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BIRBAL SAHNI INSTITUTE OF PALAEOBOTANY 53, UNIVERSITY ROAD, LUCKNOW 226 007, INDIA

PROFORMA FOR SCIENTIFIC STAFF OF GROUP IV FOR SUBMISSION OF RESUME

AND WORK CARRIED OUT BY HIM/HER FOR CONSIDERTION OF HIS/HER CASE

FOR ASSESSMENT FOR PROMOTION TO THE NEXT HIGHER GRADE IN GROUP IV

(This Proforma should be strictly followed)

1. Name of the Scientist (in Block Letters): JYOTSANA RAI

2. Date and Place of Birth : 08 - 05 -1957, Lucknow, U.P., INDIA

3. Project/ Section/ Unit : 6.2 MESOZOIC NANNOFOSSILS FROM WESTERN INDIAN CONTINENTAL SHELVES

AND THEIR PALAEOBIOGEOGRAPHIC SIGNIFICANCE

4. Date of appointment/ assessment : April 01, 2007

promotion to the present post

5. Present grade pay : Basic Rs.46380/- + Allowances.

(Scale of Pay: 37400 – 67000; GP 8700/-)

6. Academic Qualifications from Matriculation onwards:

Year Examination passed

Name of Board/ University

Name of Institution where studied

Grade/ Division

Subjects

1972 HighSchool U. P. Board, Allahabad

N.S.N. College, Lko.

Ist Hindi, English. Maths, Science, Biology

1974 Intermediate U. P. Board, Allahabad

N.S.N.College, Lko.

IInd Hindi, English, Physics, Chemistry, Biology

1976 B.Sc. Lucknow University

Lucknow University

Ist Zoology, Botany, Geology

1978 M.Sc. Lucknow University

Lucknow University

Ist Geology

1979 Proficiency Lucknow University

Lucknow University

French

. .

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Ph D Thesis: Thesis Title Year of Award University Calcareous Nannofossils from Eocene of Kutch, western India.

1988

Lucknow University, Lucknow.

7. Details of Research/Professional/Teaching Employment before joining the Institute: Name of the Organisation

Post held Scale of Pay Date

Nature of Duties

From To Geology

Department,

Lucknow University

JRF (C.S.I.R.) Rs. 400/-

01 - 03 - 79 13 - 10 - 81 Research

8. Details of research career in the Institute:

Post held Scale of Pay Date From To

Nature of Duties

JSA Rs. 425 - 700/- 14-10-81 - 18-04-84 Research

SSA Rs. 550-900/- Revised 2000/-

19-04-84 - 31-03-90 Research

JSO Rs.2000 - 3500/- 01-04-90 - 31-03-97 Research Scientist ‘C’ Rs.10,000-15200/- 01-04-97 - 31-03-02 Research Scientist ‘D’ Rs.12000-16500/- 01-04-02- 31-03-07 Research Scientist ‘E’ Rs. 37400 – 8700 01-04-07- to date Research

9. Type of work engaged in and extent of involvement since last appointment/assessment

promotion:

(a) Planning and coordination : Preparation of Research proposal. Planning of Collaborative research work with the Scientist’s of other Research organizations. Preparation of Five Yearly and Yearly

Research programmes of the Institute’s project. (b) Experimental work : Microscopic work including preparation of slides and

pellets. (c) Results interpretation : Interpretation and analysis of recovered data and preparation of Manuscripts for publication.

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(d) Electronic data processing : Preparation of data base, processing and documentation of acquired results including

processing of data. (e) Other Scientific and Technical : Actively took part in different Scientific programmes activities (Give details): in and outside the Institute. Trained manpower both as

Ph.D. student and as B.Tech Project assignment to a student from Institute of Petroleum, Dehradun and another for M.Sc. Project Assignment from Bundelkhand University, Jhansi. Provided awareness to the local school teachers and students in field excursion area to safeguard the national heritage of fossils and sections.

10. Details of research work carried-out and major achievements, if any, since last appointment / assessment promotion in the Institute, which in candidate’s view justifies his/her assessment promotion to the next higher grade:

Major achievements of my studies during this period are:

HIGHLIGHTS OF WORK DONE:

1. First record of Early Jurassic (Pliensbachian age) transgressive event in Kachchh Basin evidenced by calcareous nannofossils from Kuar Bet, Pachchham Island, Wagad Highland, Jara, Jumara and Habo domes in Mainland of Kachchh Basin. Record of Aalenian age nannofossils (oldest) from Kuar Bet, Pachchham Island.

2. Bathonian, Callovian, Oxfordian and Kimmeridgian age nannofossil assemblage record

from Jara, Jumara, and Habo domes of Mainland and Wagad Highland of Kachchh Basin. 3. Late- early Tithonian age integrated nannofossil- Himalayites cf. H. sideli ammonite

biostratigraphy from type Rupsi Shale Member of Baisakhi Formation in Jaisalmer Basin. 4. Albian to Maastrichtian age nannofossil biostratigraphy and recognition of seventeen

biostratigraphic zones well tagged with known late Cretaceous nannofossil zones from Tanot Bore-well1, Jaisalmer Basin. A new Formation (Tanot Formation) in the said borewell is erected.

5. Record of latest Maastrichtian (CC 26b) age nannofossil assemblage from Aladi

Formationof Vriddhachalam area, Cauvery Basin. 6. Record Late Maastrichtian age calcareous nannofossils of CC25/ UC 20bTP zone from

Ottakoil Formation, Cauvery Basin. 7. Record of nannofossils from Kallamendu Formation, Cauvery Basin. 8. Record of precise LPTM by marker nannofossils and Carbon –isotope excursion. 9. Record of Late Middle Eocene age calcareous nannofossil assemblage from Siju limestone,

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Garo hill, Meghalaya and correlated with coeval more diversified Kachchh assemblage. 10. Record of Oligocene age nannofossil assemblage from Maniara Fort Formation, Kachchh

is amongst very few marine Oligocene records from India. 11. Record of nannofossil assemblage from Quaternary sediments of Harshad estuary in

Saurashtra Coast and recovery of reworked Cretaceous/ Tertiary nannofossils suggesting a possible K/T section in the vicinity.

12. A rare microfossil group represented by siliceous dinoflagellates is recorded from Neill

Island of Andaman - Nicobar Islands and from Southern Indian Ocean sediments suggesting interplay of cold water containing siliceous microfossils versus calcareous plankton carrying warm water masses.

13. A Catalogue containing all the nannofossils recorded from India with its locality, age,

stratigraphic level, horizon, range is a ready reference for the beginners and for oil Industry. 14. Record of a very rare microfossil group (Ascidian spicules) with calcareous nannofossils

from Quaternary age core samples of Bay of Bengal.

WORK OTHER THAN PROJECT PROGRAMMES DST Sponsored Project:

Project Title: Integrated nannofossil-ammonite biostratigraphy of Wagad Island, Kachchh Basin:

palaeoenvironmental and palaeobiogeographic implications.

DST Project No: SR/S4/ES-521/2010 (G)

PI: Dr. Jyotsana Rai

Co-PI: Prof. D. K. Pandey, Geology Department, University of Rajasthan, Jaipur.

Dr. Rahul Garg, ex Scientist-F and Emritus Scientist at BSIP, Lucknow

Objectives of the Proposal:

(i) To identify and document nannofossil assemblages for Middle Jurassic successions of Wagad region (To carry out detailed morphotaxonomical study of significant nannofossil taxa in the assemblage and to make qualitative and quantitative analysis of species distribution, documentation of FAD’s and LAD’s of marker taxa, biozonation, assignment to standard nannofossil zones).

(ii) To integrate nannofossil and ammonite biozones. (iii) Identification of marker horizons in the Wagad region and to provide precise time bracket.

Summary of Project Progress: (i) Two field excursions were conducted (20th March, 2012-3rd April, 2012; 03 January 2013-

21st January 2013 in Wagad and adjoining areas. Traverses along Bharodia section, Patasar Talao, Trambao River Section, Chitrod Dome, Shivlakha Dome, Washtawa Dome, Nara Dome were taken. Besides these, traverses along Kuar bet, Sadhara Dome in Patcham Island, Khadir Island and Gangta Bet, Bela Island in the vicinity were also taken to check availability of nannofossils in other islands (Jumara Dome, Jhura Dome, Ler

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Section, Gangeshwar Dome) to compare nannofossil yield. Selected samples were processed for dinoflagellate cysts and productive levels are identified.

(ii) All the slides were prepared and productivity was marked. (iii) Preservation of nannofossils recorded from from Patasar Talao Section, Nara Dome,

Kantkot, Bharodia Section, Trambau River Section, Khadir Island and Washtawa Formation are moderate to good. Exceptional preservation displaying highly diverse nannofossils are recovered from Callovian/ Oxfordian sequences of Mainland domes. Well preserved dinoflagellate cyst assemblages are recovered from several levels from, Nara Shale, Kantkot ammonoid bands, Patasar shale, Wagad sandstone.

(iv) Documentation of nannofossils from Trambau River Section constrained by datable ammonites is carried out. Documentation of dinoflagellate cysts from Patasar Talao Section is done and nannopfossil documentation from Nara Shales is in progress.

Details of the work carried out during the period are given below: (a) PROJECT PROGRAMMES: KACHCHH BASIN

PATCHAM ISLAND The Patcham Island represents the westernmost highland amongst Island belt containing

oldest rocks in Kachchh Basin. At Point 16 in Kuar Bet (=Mori Bet) the exposures are seen in a hillock. The top of the hill is full of pelycepods and rare gastropod shells and the lower part shows current and flaser bedding. In the middle of current lamination a sample (GPS location 23° 59’40”N: 69°42’28”E) belonging to Dingi Hill Member of Kaladongar Formation has yielded calcareous nannofossils.

The list of nannotaxa recovered are viz. Biscutum finchii, Biscutum sp., Bussonius prinsii, Crepidolithus crassus, C. pliensbachensis, Crucirhabdus primulus, Diazmatolithus lehmanii, , Discorhabdus criotus, Ethmorhabdus gallicus, Lotharingius contractus, Mitrolithus elegans, Octopodorhabdus sp., Schizosphaerella sp., Triscutum sp., Tubirhabdus patulus, Watznaueria barnesae, W. fossacincta.

Presence of B. finchii (FAD NJ5 - LAD NJ6), B. prinsii (NJ5B), C. primulus (NJ5B) and D. criotus (FAD NJ7) suggests the placement of assemblage in NJ5 to NJ7 zones of Pleinsbachian to Torcian age. NJ5 represents upper Pleinsbachian whereas NJ6-7 indicates lower Toarcian. This has wide palaeogeographical implication as it suggests that after faulting the transgressive event in Kachchh basin might have taken place during Pleinsbachian- Toarcian time i.e. ca.?12my. earlier than Late Bajocian (ammonite: Leptosphinctes sp. and coral: Isastrea bernardiana records). However, earliest transgressive event in Bajocian time in western India is suggested by many earlier workers. Record of upper Pleinsbachian age nannofossils from Masirah Island from Sultanat of Oman, Arabia and ?Aalenian age nannofossils ffrom Kuwait strengthens this finding. Reworked Pleisbachian- Toarcian age nannofossils were earlier recovered from Callovian age nannofossil assemblage of Jara, Habo, Jumara domes and from Oxfordian age sediments of Wagad Highland.

(KACHCHH MAINLAND)

JARA, JUMARA AND HABO DOMES

Jara Dome, situated on the extreme western part of Kachchh Mainland displaying gypsiferous shales in the lower part of escarpment section is precisely dated on moderately preserved but diverse nannofossil assemblage belonging to Lower Callovian age sediments of NJ13 Zone of Bown et al. (1988).

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Jumara Dome (23°40’N: 69°06’E) is the type section of Jumara Formation of Biswas

(1977), located in NW direction about 80 km of Bhuj. The Jurassic sequences exposed in Jumara dome are mainly Jhurio, Jumara and Jhuran formations. The calcareous nannofossil assemblages at Jumara is well diversified and moderately preserved with pronounced etching is seen in Bajocian - Bathonian age nannofossils of the Jhurio Formation as well as Oxfordian age nannofossils from sediments underlying Dhosa Oolite. The nannofossil assemblages from various levels demarcate Bajocian/ Bathonian, Bathonian/ Callovian and Callovian/ Oxfordian boundaries in Jumara Dome.

Habo Dome is the biggest dome in Kachchh mainland exposing Jurassic rocks in small

inliers belonging to the Jhurio, Jumara and Jhuran formations. The assemblage is moderately preserved and well diversified. The Jhurio Formation exposed in the core of the dome have yielded Watznaueria barnesae, W. britannica, Cyclagelosphaera margerelii, Lothringuis contractus, Discorhabdus striatus, and L. velatus. The assemblage is dated Upper Bajocian – Lower Bathonian in age. The Upper Jumara Formation underlying the Dhosa Oolite is dated Late Callovian- Oxfordian. The age of oldest Jhuran Formation is thus constrained from Divisum (NJ 15 Upper Lower Kimmeridgian) to Lower Fallauxi Tethyan ammonite NJ 20A Zone of Bralower et al. 1989 which corresponds with Middle Upper Volgian NJ 16 Zone of Bown et al., 1988.

On the basis of presence of limited marker taxa the Bathonian/Callovian, Callovian/ Oxfordian and the Oxfordian/Kimmeridgian boundaries are delineated from Jhurio, Jumara and Jhuran formations exposed in Habo Dome.

Reworked Pliensbachian – Toarcian age (Early Jurassic) reworked nannofossils are seen from Middle- Late Jurassic nannofossils assemblages of all these domes. Thus providing clue for Pliensbachain age earliest transgressive event in Kachchh Basin and rejecting all the existing views of Middle Jurassic earliest transgression in Kachchh Basin. JAISALMER BASIN BHADASAR FORMATION Nannofossil from sediments associated with Himalayaites cf. S. sideliammonite (a Late Late Tithonian global marker), recovered from topmost hard band of type Rupsi Shale Member of Bhadasar Formation exposed in Rupsi village of Jaisalmer is dated late Early Tithonian. Occurrence of Z. embergeri (FAD), N. compressus (FAD) and E. gallicus (LAD) in the assemblage is taken here as potential taxa for NJ 20 (T) Conusphaera mexicana Zone assignment of late Early Tithonian age. NJ 20 (T) Zone of Bralower et al. (1989) encapsulates Tethyan lower to middle Tithonian time slice (CM22n – CM20). The assemblage can be more precisely correlated to NJ 20b (T) Middle Tithonian Polycostella beckmanni subzone. In boreal realm FO of H. chiastia and LO of E. gallicus suggests the assemblage in time bracket of late Early Tithonian (NJ 17b). PARIWAR FORMATION (SURFACE)

Pariwar Formation in the Jaisalmer Basin, Rajasthan has been precisely dated for the first time as early Middle Albian on the basis of presence of a well diversified, moderately preserved calcareous nannofossil assemblage of the upper part of Chiastozygus litterarius Zone CC7b/ Prediscosphaera columnata Zone CC8 of Sissingh 1978 corresponding with NC8/9 zones of Bown et al. (1998). Presence of nannoconids in the assemblage indicates Tethyan affinity and Seribiscutum primitivum showed presence of bipolar high cold water taxon from Austal province to mid latitudinal position. The Tethyan nannofossil laden water current appears to have been mixed with cold water current during Aptian – Albian time (Kale and Phansalkar, 1992) and continued up to

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Campanain time. Record of B. constans, Z. erectus indicates surface water nutrient rich upwelling conditions.

JAISALMER BASIN (SUBSURFACE)

TANOT BOREWELL- 1

Thesis entitled “Subsurface Cretaceous calcareous nannofossil biostratigraphy from Tanot Bore well-1, Jaisalmer basin, Rajasthan, India.” of Ms. Abha as BSRS was supervised, submitted to the Geology Depatment, Lucknow University, Lucknow on 19th March 2012 and awarded on 25th September 2012. Highlights of Thesis:

1. In all 222 nannofossils species belonging to 86 genera and 22 families were recovered from 114 bore-well samples which are delineated in 17 alpha-neumeric biozones and 5 subzones on the basis of last/ first occurrences of marker taxa.

2. Twenty three light-microscopic plates containing family-wise nannotaxa and 4 scanning electron microscopic plates are prepared.

3. The recovered nannotaxa have been plotted with respect to stratigraphic distribution, preservation factor, and r & k-strategist mode related frequency distribution.

4. On the basis of recorded global marker taxa A. octoradiata, R. levis, T. orionatus, E. eximius S. primitivum Z. biperforatus Z. noeliae Z. kerguelenesis R. planus E. rarus H. chiastia A. albianus C. kennedyi S. gausorhethium Z. xenotus B. africana E. turriseiffelii and B. stenorhetha the age assigned for these sediments is from Albian to Lower Maastrichtian.

5. Record of high latitude cold water forms viz S. primitivum, R. parvidentatum, B. dissimilis, A. octoradiata, Z. kergulensis and Nephrolithus spp. with warm water taxa W. barnesae and nannoliths viz. Braarudospherids and nannoconids indicate mixing of warm and cold water currents in Jaisalmer basin during Late Cretaceous time situated at mid latitudes (ca. 30° South).

6. The recorded nannofossil assemblage broadly indicates shelf deposit. 7. Pariwar Formation in the Jaisalmer Basin, Rajasthan has been precisely dated for the first

time as early Middle Albian on the basis of presence of a well diversified, moderately preserved calcareous nannofossil assemblage of the upper part of Chiastozygus litterarius Zone CC7b/ Prediscosphaera columnata Zone CC8 of Sissingh 1978 corresponding with NC8/9 zones of Bown et al. (1998).

8. Significant nannofossil taxa include Farhania varolii (Jakubowski, 1986) Varol, 1992; Prediscosphaera columnata (Stover, 1966) Perch-Nielsen, 1984 and Seribiscutum primitivum (Thierstein, 1974) Filewicz et al. in Wise and Wind, 1977. These forms are zonal or subsequent markers in various zonal schemes (Jakubowski, 1987; Mutterlose, 1992; Bown et al., 1998; Jeremiah, 2001). However, Sissingh’s and Mutterlose’s zonal classifications of mid-latitude have been followed here while other zonal schemes are tenable to high latitude.

9. Cyclagelosphaera margerelii Noël, 1965; Faviconus multicolumnatus Bralower, 1989 in Bralower et al., 1989; Tubodiscus jurapelagicus (reworked) (Worsley, 1971) Roth, 1973 are reworked forms present in the assemblage.

10. Presence of nannoconids in the assemblage indicates Tethyan affinity and Seribiscutum primitivum showed bipolar high cold water distribution. The Tethyan nannofossil laden water current appears to have mixed with cold water current during Aptian – Albian time

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(Kale and Phansalkar, 1992). Record of B. constans, Z. erectus indicates surface water nutrient rich upwelling conditions.

11. On the basis of recorded global marker taxa A. octoradiata, R. levis, T. orionatus, E. eximius S. primitivum Z. biperforatus Z. noeliae Z. kerguelenesis R. planus E. rarus H. chiastia A. albianus C. kennedyi S. gausorhethium Z. xenotus B. africana E. turriseiffelii and B. stenorhetha the age assigned for these sediments is from Albian to Lower Maastrichtian.

12. Presence of B. enormis, B. matalosa, B. parca expansa and L. carniolensis indicates mixing of taxa from Austral Province current. The recorded nannofossil assemblage broadly indicates shelf deposit.

11. Interdisciplinary/Inter-institutional/Collaborative research activities in which the

candidate is participating since last appointment/assessment promotion in the Institute (Please mention all relevant details and extent of involvement along with others, if any in such activities)

CENTRAL INDIA

A rich and precisely datable calcareous nannofossil assemblage is recovered from the infra-trappean sandy succession conformably overlying the marl bed of the Bagh Formation, exposed at 1 km north of the Chakrud village, Zeerabad area, Dhar district, M.P. The nannofossil assemblage belongs to infra- trappean sandy facies overlying the typical carbonate facies of the Bagh Formation which has been referred to as the Lameta Formation (Kumar et al. 1999, Field Guide). The Chakrud nannofossil assemblage is moderately preserved and fairly diverse, represented by forty seven species. It shows a distinct Late Cretaceous aspect but completely lacks any typical Maastrichtian taxa. Occurrence of cosmopolitan markers Arkhangelskiella cymbiformis, Eiffellithus eximius, Broinsonia parca parca, Eprolithus floralis, Heteromarginatus bugensis, Lithraphidites prequadratus, Marthasterites furcatus, Marthasterites simplex and Zegrhabdotus diplogrammus clearly indicates Early Campanian age. The assemblage is assigned to the standard nannofossil CC18 / UC14 zone. Discovery of Early Campanian marine microplankton demands reappraisal of the existing models on the age and depositional environment of the Bagh - Lameta succession of the Bagh area. The nannofossil evidence provides a compulsive constraint for the upper age limit of the infra-trappean sandy succession (Lameta Formation) overlying the Bagh Formation, which is broadly assigned Late Turonian - Santonian age on various mega and microfossil evidences. It further indicates that subsequent to the deposition of the Coralline Limestone, Nodular Limestone and marl, marine/estuarine conditions continued uninterrupted at least up to the Early Campanian during the deposition of sandy horizon. It is pertinent to note that the dinosaur egg-bearing Lameta sediments in the Bagh area, widely considered to be of Maastrichtian in age, are mostly represented by sandy and nodular calcrete overlying the Coralline Limestone of the Bagh Formation and underlying 1 m thick red quartzitic sandstone capped by the Deccan Trap occurring more or less in the same stratigraphic position as the nannofossil bearing calcareous sandy facies (Mohabey, 2001). Taking into consideration the previous record of Late Turonian nannofossils from the Nimar Sandstone (Jafar, 1982), a Late Turonian - Early Campanian time bracket for the Bagh - Lameta succession in the Bagh area was proposed.

(J. RAI; R. GARG & S. KUMAR) MEGHALYA

Thirty-five samples representing significant Siju limestone Formation, exposed in the Dilni river section, Garo Hills, Meghalaya were processed to check nannofossil productivity. A low diversity assemblage is recovered. Abundance of cosmopolitan marker viz. Reticulofenestra reticulata and presence of R. umbilica indicate potential for demarcation of Lutetian - Bartonian

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boundary in the area. (J. RAI & R. GARG)

MIZORAM The samples from Ruata Quarry, Turial Bungalow Section and Turial Prayer Point Section

representing Bhuban Formation have yielded datable nannofossil assemblages. Though the Bhuban Formation is broadly mega and micro- fossil lacking thick calcareous sandstone unit and its precise age has been debated for want of fossils.

1. The Ruata Quarry R1 sample is dated NN2 - NN4 Late Burdigalian – Early Langhian of Early- Middle Miocene, whereas R3 number sample is NN11B – NN12 Messinian i.e.Late late Miocene in age. 2. The Turial Bungalow Section has two productive levels represented by TB3 which is dated NN8 – NN12 of Middle – Late Late Miocene age and the TB2 sample is dated NN13 – NN19 zones of Pliocene age. Very close sampling at the boundary in this section of Mizoram is required to be done to resolve and calibrate the Mio-Pliocene boundary globally. 3. Only one sample TP3 from Turial Prayed Point section has been dated NN5 - NN11B of Middle to Latest Miocene age.

(J. RAI, J. MALSAWMA, C. LALRINCHHANA, PAUL LALNUNTLUANGA, V. Z.

RALTE AND R. P. TIWARI)

SOUTHERN INDIAN OCEAN

Siliceous dinoflagellates represented by solitary form Actiniscus pentasterias with numerous variations is reported from upper one m. deep core from Southern Indian Ocean. The assemblage shows its presence throughout the studied interval which characteristically represents siliceous ooze with subordinate calcareous nannoplankton.

(J. RAI, R. GARG & N. KHARE) BAY OF BENGAL

Sixty two samples with two cm. each of sample difference from a core of 124 cm depth

from Bay of Bengal area bearing no. BOBCore1 have yielded calcareous nannofossils of Quaternary age. The assemblage is very diverse, well- preserved and indicates presence of Braarudosphaera bigelowii, Calcidiscus leptoporus, Ceratolithus acutus, C. cristatus, C. simplex, C. telesmus, Coccolithus pelagicus, Cyclicargolithus abisectus, Dicoaster brouweri, D. calcaris, D. pansus, D. quinqueramus, D. surculus, D. triradiatus, Emliania huxleyi, Gephyrocapsa carribbeanica, G. oceanica, G. parallela, G. sinuosa, Helicosphaea carteri, H. hyaline, H. inverse, H. pavimentum, H. wallichii, Neosphaera coccolithomorpha, Pontosphaera discopora,, Pseudoemiliania lacunose, Reticulofenestra asnoi, R. haqii, R. pseudoumbilicus, Rhabdosphaera clavigera, R. stylifera, Scapholithus fossilis, Schyphosphaera globulata, S. intermedia, S, pulcherima, Sphenolithus abies, S. dissimilis, S. moriformis, Syracosphaera pulchera, Thoracosphaera albertosiana, T. heimii, T. operculata, T. pelagica, Triquetrorhabdulus rioi, Umbilicosphaera sibogae var. sibogae and a variety of ascidian spicules. The decrease in calcium carbonate percentage is marked by sharp fall in productivity of coccoliths. Six plates are prepared.

(J. RAI, HEMA ACHUTAN, NAGASUNDARAM)

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KACHCHH BASIN

Nannofossil assemblage of Quaternary age is recovered from estuarine sediments of Harshad estuary, situated on the north-western part of Saurashtra coast. The assemblage contains flood abundance of Gephyrocapsa oceanica, Emiliania huxleyi, Helicosphaera carteri var. wallichii and subordinate H. kamptnerii. The assemblage contains reworked late Cretaceous Watznaueria barnesae, Micula decussata, Arkhangelskiella cymbiformis, Aspidolithus parcus, Rhagodiscus splendens, Cribrosphaerella ehrenbergii, Orastrum campanensis, Braarudosphaera bigelowii, Eprolithus floralis, Biscutum constans, Coronocyclus nitescens, Markalius inversus and Palaeocene-Oligocene age Calcidiscus macinyrei, Coccolithus pelagicus, Cribrocentrum reticulatum, Cyclicargolithus floridanus, Coccolithus doronicoides, Cyclococcolithus luminis, Discoaster saipanensis, D. barbadiensis, D. multiradiatus and calcareous dinoflagellates represented by Thoracosphaera albertosiana, T. operculata, T. pelagica and T. saxea. Possibility of a section containing late Cretaceous and Palaeogene age nannofossils in close vicinity is inferred a reason for these reworked species in a coastal marine set up.

(J. RAI, V. PRASAD AND V. SINGH)

JAISALMER BASIN Integrated collaborative research work on Jurassic age calcareous nannofossil – ammonite in a sequence stratigraphic frame- work from Jaisalmer Basin was initiated with Dr. D.K. Pandey of Department of Geology, University of Rajasthan, Jaipur. A comprehensive field work in Mesozoic sections of Jaisalmer area was conducted and material was prepared. Productive levels are being used in erecting an integrated sequence bio-stratigraphy. The work is under progress.

(J. RAI & D.K. PANDEY) CAUVERY BASIN

1. Moderately diversified with low frequency nannofossil assemblage comprising over twenty

species are recorded from one (S-13) calcareous marl sample of Ariyalur Formation situated North of the village Aladi exposed on either side of the road displaying friable limestone beds in a stream section bearing Lat : N11°37’47”; Long: E79°21’4”.

2. The recovered nannofossil taxa are of latest Maastrichtian in age. 3. On the basis of the occurrence of zonal marker taxa Micula prinsii the assemblage is

asssigned to CC 26b (Perch- Nielsen, 1985) corresponding with UC 20d TP of Burnett in Bown (1998) of latest Maastrichtian age. It is a low latitude marker and is indicative of latest Maastrichtian age approximately 50,000 years prior to the K/T boundary.

4. Besides this, frequent abundance of Petrobrasiella? bownii in both very small and big sizes (3-4 µm to 10 µm diameter) along-with Ceratolithoides kamptneri, Arkhangelskiella maastrichtiana, Calculites obscurus attests to this zonal placement.

5. A high latitude Maastrichtian age genus Nephrolithus represented by N. miniporus is also present in the assemblage indicating presence of cold water current in Southeastern part of India during latest Maastrichtian time.

6. Reworked Campanian age forms are represented by Ceratolithoides aculeus, Nannoconnus spp. and Haqius circumradiatus are also present in the assemblage. The detailed study may provide exact K/T boundary level as Pondicherry Formation of Palaeocene age is exposed in the vicinity.

J. RAI, MALARKODI, ABHA

Collaborative research work incorporating integrated nannofossil and Geochemistry of K/T section of Cauvery Basin with Dr. Mu. RamKumar, Department of Geology, Periyar University, Salem is initiated on 18. 10. 2007 vide letter no. BSIP/ IV/ Coll.Res/2007-08/L- 866. A poster was prepared

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and an abstract entitled “Calcareous nannofossils from Ottakoil Formation (Late Maastrichtian), Cauvery Basin, South India’ containing datable nannofossil assemblage yielded from only productive sample was presented at a conference at BSIP 2007.

(J. RAI & MU. RAMKUMAR)

A Project entitled “Integrated nannofossil - ammonite biostratigraphy of Wagad Island, Kachchh Basin: palaeoenvironmental and palaeobiogeographic implications.” sponsored by (DST project No. SR/S4/ES-521/2010(G)) was awarded and initiated from September 2012.

J. RAI, D.K. PANDEY & R. GARG

WAGAD HIGHLAND, KACHCHH BASIN

First record of bennetitalean fossil flower represented by Williamsonia sp. along with Carpolithes (seed), from the upper part of the Callovo- Oxfordian Washtawa Formation (Kantkot ammonite Bed) is recorded. The specimen is comparable with W. kakadbhitensis of Albian age from the Bhuj Formation of Kachchh Mainland area. All the known record of Williamsonia is from early to late Cretaceous sediments in India and this is about 40 million years earlier record. The horizon with plant fossils is rich in datable ammonites and also contains nannofosils. The mainland sections display exceptional preservation of Callovian age calcareous nannofossils but in Oxfordian strata (Dhosa oolite) nannofossils are not well preserved.

In the bed of the Trambau River between Kantkote and Jharsa villages a succession of brick-red to yellowish (iron -rich) calcareous, mudstone is exposed. One bedding surface at the nala is, for several hundred metres, studded with a variety and size range of ammonoids, belemnites, large bennetitalean fossil wood logs and pieces with attached fructifications and seeds at places, along with large Thalassinoides burrows. At places symmetrical ripple marks are also seen which suggest wave influence and hence comparatively shallow-water conditions. The ammonite assemblage has been dated as late Middle Oxfordian for this part of the succession. More precisely, the ammonite assemblage belongs to Oxfordian Transversarium Zone, Schilli Subzone (Krishna et al., 1994, 1995). Associated with the ammonites is a moderately diverse nannofossil flora, represented by Axopodorhabdus cylindratus Biscutum dubium, Carinolithus magharensis, Crepidolithus perforata, Cyclagelosphaera margerelii, C. tubulata, Ethmorhabdus gallicus, Lotharingius contractus, L. sigillatus, Stephanolithion bigotii bigotii, Stradnerlithus geometricus, S. fragilis, Triscutum expansus, Triscutum spp., Watznaeuria barnesae. W, britannica, W. ovata etc. The calcareous matrix of the sandy Nara Shales has been provided by calcareous nannofossils. The low-diversity, moderately preserved nannofossils from the upper part of Nara Shales Member of the Washtawa Formation can also be placed, with confidence, in the NJ 15 Cyclagelosphaera margerelli Zone of Bown et al (1988) of Lower Oxfordian (Cordatum AZ) to Lower Kimmeridgian (Autissiodorensis AZ). The Wagad Island section contains excellent datable ammonite in hard calcareous bands and moderately –preserved nannofossils in calcareous sandy shales in between these hard bands. Early and early Middle Oxfordian ammonites are recorded from Mainland Kachchh, whereas Middle and Late Oxfordian ammonites have been recorded from Kantkote of the Wagad region. Possibly, the mainland area underwent sediment starvation, while sedimentation was going on in Wagad Island. The part of the section in question may correspond to a maximum flooding zone.

GANGTA BET Gangta Bet is located between the Khadir Island and Wagad highland (N 23°46’ to N 23°

43’ longitude, E 70°30’ to E 70°33’ latitude). The stratigraphy of Eastern Kachchh designated by Biswas (1977) is represented by inter-related rock- units exposed in unconnected outcrops of Wagad, Khadir, Bela and Chorar. In Gangta Bet the base of Gangta Member is exposed in the

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central dome below Ravechi Mata temple and is highly fossiliferous containing brachiopods mainly Rhynconella and Terebratula. Few bands are rich in ammonites and other fossils and serve as key bed. Youngest of them is called Gangta Ammonite bed/ bands. These bands are chocolate coloured, haemtitic, pebbly with quartz pebbles. Large chunks of fossil wood and ammonites present with it are diagnostic and studied.

The anatomical details of two new fossil woods recovered from top of Gangta Bet Member of Khadir Formation exposed around the core of the central dome of Gangta Bet occurring near fault region. It is designated as Aurocarioxylon wagadiensis n. sp. and Podocarpoxylon gangtensis n. sp. The level of the collected samples is the youngest of five designated members of Biswas (1971, 1977). Callovian – to late Middle Oxfordian age ammonites are known from Gangta Bet and the marker Gangta Ammonite band was assigned to Helenae Assemblage Zone of late Middle Oxfordian age. Presence of low diversity nannofossil assemblage with moderate preservation from all the five samples collected from the profile indicates Callovian to slightly younger Kimmeridgian/ Tithonian age assignment. Presence of Faviconus multicolumnatus, Nannoconus sp., Placozygus fibuliformis, Prediscosphaera cretacea in the nannofossil assemblage suggests early Cretaceous sediments in the vicinity. Co-investigator for carrying out Nannofossil studies in a MOES Project entiled “High Resolution Palaeoclimatic studies from Bay of Bengal”

(DRS. RAJIV NIGAM, RAJEEV SARASWAT, PRANAB DAS, G.N. NAIK, VANDANA PRASAD & S.M. HUSSAIN & J. RAI).

12. Details of field work undertaken since last appointment / assessment promotion in the Institute:

2007- 2008 –A field excursion to Jaisalmer was conducted and samples from Lathi (Thaiyat, Member), Jaisalmer (Joyan, Fort, Bara Bagh, Kuldhar and Jajiya members) and Baisakhi and Bahdasar formations were collected. Samples from Mataji ka dungar Formation and Lathi formation from Barmer basin were also collected for the recovery of calcareous nannofossils.

J. Rai & D.K. Pandey (Department of Geology, University of Rajasthan, Jaipur)

2008- 2009 - A field- work was conducted in Jaisalmer and adjoining areas and samples from various members of Jaisalmer, Baisakhi and Pariwar formations were collected. An integrated ammonite – nannofossil studies in a sequence stratigraphic framework of Mesozoic of western Indian basins is under progress.

J. Rai, A. Singh & D.K. Pandey (Department of Geology, University of Rajasthan, Jaipur) 2009- 2010 - A field excursion to Kachchh was conducted and samples from Kharol, Nara Shale and Chitrod sandstone members of Washtawa Formation, Patasar shale and Fort sandstone, Adhoi members of Kantkot Formation, and Gamdau Formation of Wagad Highland were collected to check the nannofossil productive levels. Samples from Kakindia Bet area of Khadir Island were also collected for recovery of calcareous nannofossils. Representative calcareous mudstone sample of Chari Formation from Jawahar Nagar section from Mainland Kachchh were also collected.

J. Rai 2011- 2012- A field excursion to Kachchh area was conducted and samples were collected from (Bharodia section in Kantkot Dome, Patasar shale Near Patasar water tank, Chitrod Dome, Shivlakha Dome, Washtawa Dome, Nara Dome) of Wagad Highland. Besides this, Lodrani section of Bela Island, Amarapur section of Khadir Island, Kuar Bet and Sadahra Dome sections

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in Pachchham Island were also covered and samples from Matanomadh section were also collected.

J. Rai, R. Garg & A. Singh 2012 – 2013 – A field work to Mizoram area was conducted and samples from Middle- upper Bhuban Formation exposed at Ruata Quarry Section, Bawngkawn – Durtlang section, Chatlang- Chandmari section, Turial Prayer point, Turial Road side and Turial Bunglaw sections, Tuithum Quarry Sairong section, were collected to find levels of datable nannofossils in otherwise practically devoid of/ confined to very thin and limited levels of macro and microfossils.

J. Rai, R. P. Tiwari, J. Malsawma, Lalchhanhima 2012 – 2013 - A field excursion to Kachchh area was conducted and samples from Kuar Bet, Chaper Bet, Dingi Hill, Sadhara Dome of Patcham Island and Habo Dome, Gangeshwar Dome of Mainland were collected to find preservation and abundance of calcareous nannofossils.

J. Rai 2012-2013 – A field excursion to Kachchh was carried out and systematic sampling from Jumara Dome, Jhura Dome, Ler section, Sadhara Dome, Gangta Bet, Trambau River section, and Ghuneri section are collected.

J. Rai, D. K. Pandey & A. Singh

13. Publications (in chronological order, please enclose reprints of five of your best papers published since last appointment / assessment promotion in the Institute and indicate the same in the list):

a) Original Research Papers (Please mention Co-author (s), if any, title, journal, volume, year

and page numbers):

(i) upto the last appointment/ assessment promotion in the Institute: 1. RAI, J. (2002) An overview of Nannofossil Records from India. Journal of the Palaeontological Society of India, Lucknow, 47: 85-91. 2. RAI, J. (2003) Early Callovian Nannofossils from Jara Dome, Kachchh, Western India. Journal of the Geological Society of India, Bangalore, 61: 283- 294, Impact Factor, 0.217 . 3. RAI, J.; UPADHYAY, R. & SINHA, A. K. (2004) First Late Triassic nannofossil record from the Neo -Tethyan sediments of the Indus - Tsangpo Suture Zone, Ladakh Himalaya, India. Current Science, 86 (6): 774 - 777. 4. UPADHYAY, R.; RAI, J.; & SINHA, A. K. (2005) New record of Bathonian – Callovian calcareous nannofossils in the eastern Karakoram block: a possible clue to understanding the dextral offset along the Karakoram fault. Trera Nova, 17: 149 – 157, Impact Factor, 1.739. 5. RAI, J. (2006) Late Miocene siliceous endoskeletal dinoflagellates from the Sawai Bay Formation, Neill Island, Andaman Sea, India. J. Micropaleontology, 25: 37 – 44, Impact Factor, 0.243. 6. RAI, J. (2006) Discovery of nannofossils in a plant bed of the Bhuj Member, Kutch and its significance. Current Science, 91 (4): 519 – 526, Impact Factor, 0.728.

(ii) Since last appointment/assessment promotion in the Institute: ♣ Papers attached

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♣ 1. Rai, J. (2007). Response to comments of Dr. S.K. Biswas on nannofossils in a plant bed. Current Science 92: 571-573. (IF-0.935) 2. Rai, J. (2007). Middle Eocene calcareous Nannofossil Biostratigraphy and Taxonomy of onland Kutch Basin, western India. Palaeobotanist 56: 29-116. 3. Rai, J. (2007). A catalogue of Calcareous Nannoplankton from India. Diamond Jubilee Special Publication, Birbal Sahni Institute of Palaeobotany, Lucknow: pp 1-77. ♣ 4. Rai, J & Garg, R. (2007). Early Callovian nannofossils from Kuldhar Section, Jaisalmer, Rajasthan. Curr. Sci. 92: 816-820. (IF-0.935) 5. Rai, J.; Garg, R. & Khare, N. (2008). “Actiniscus pentasterias, an endoskeletal siliceous dinoflagellates from Southern Ocean sediments” Indian Journal of Marine Sciences, 37(4), 430-434. (IF.0.422) 6. Rai, J. & Garg, R. (2009). Late Middle Eocene (Bartonian) age calcareous nannofossiols from Dilni river section, Meghalaya, nnortheastern India” published at the IGCP – 2007 Proceedings volume on the International Conference entitled “Geo - environment challenges Ahead”, Mac Millan Publishers, pp. 275- 291. 7. Rai, J. (2009). “Nannofossils” Comments in response to a paper entitled “Nannofossils or Ammonites- how real is the age paradox at the Jurassic Jaisalmer” by S. Jain Current Science Journal, vol. 97, no. 2, 133. (IF-0.935) 8. Rai, J. & Abha (2010.) Calcareous nannofossils and their applications. Gondwana Geological Magazine, 25(1), 149-159. 9. Ramkumar, Mu., Anbarasu, K., Sugantha, T., Rai, J., Sathish, G., & Suresh, R. (2010). Occurrences of KTB exposures and Dinosaur nesting site near Sendurai, India-An initial report. International Journal of Physical Sciences, 22(3), 573-584. (IF- 0.55) 10. Rai, J.; Mishra, V.P.; Sahni, A.; Singh A. and Vega. Francisco J. (2013). On some Paleogene and Neogene crabs of Kachchh, Western India. Bulletin of the Mizunami Fossil Museum, no. 39, p. 39–45, 2 figs., 1 pl. Mizunami Fossil Museum Bulletin, Japan. ♣ 11. Samanta, A., Sarkar, A., Rai, J. and Rathore, S. S. (2013). Late Paleocene- Eocene carbon isotope stratigraphy from a near – terreastrial tropical section and antiquity of Indian mammals. Journal of Earth System Sciences, vol. 122, no. 1, pp. 163- 171, Indian Acad. Sciences. (IF- 0.82) 12. Mu. Ramkumar; Sugantha T., and Rai, J. (2013). Facies and textural characteristics of the Kallamedu Formation, Ariyalur Group, Cauvery Basin, South India: Implications on Cretaceous-Tertiary Boundary (KTB) events Special volume of Springer Verlag (Ed. Ramkumar) on the Sustenance of Earth Resources, Heidelberg, Germany., pp.263- 284 . 13. Rai, J.; Ramkumar, Mu. and Sugantha, T. (2013). Calcareous nannofossils from the Ottakoil formation, Cauvery Basin, South India: Implications on age, biostratigraphic correlation and palaeobiogeography Special volume of Springer Verlag (Ed. Ramkumar) on the Sustenance of Earth Resources, Heidelberg, Germany, pp. 109- 122.

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♣ 14. Samanta, A., Bera, M. K., Ghosh, R., Bera, S., Filley, T., Pande, K., Rathore S.S., Rai, J. and Sarkar, A. (2013). Do the large carbon isotopic excursions in terrestrial organic matter across Paleocene–Eocene boundary in India indicate intensification of tropical precipitation? Palaeogeography, Palaeoclimatology, Palaeoecology, 387, 91–103. (IF – 2.745) 15. Rai, J., Malarkodi, N. and Abha (2013). Terminal Maastrichtian age calcareous nannofossils preceding K/T mass extinction from Ariyalur Formation, Vridhhachalam area, South India. Journal of the Geological Society of India, Special Volume (Eds. Malarkodi, Gerta Kellar, Nallapa Reddi & B.C. Jaiprakash) pp. 439- 477. (IF – 0.567) 16. Rai, J., Singh, A. and Garg, R. (2013). Calcareous nannofossils of Albian age from Tanot Well-1, Jaisalmer Basin, Rajasthan and its palaeobiogeographic significance. Palaeontological Society of India Journal, 58(1), 67-73. ♣ 17. Rai, J., Singh, A. and Pandey, D.K. (2013). Early to Middle Albian age calcareous nannofossils from Pariwar Formation of Jaisalmer Basin, Rajasthan, western India and its significance. Current Science Journal, 105 (11), 1604 - 1611. (IF – 0.91)

TOTAL IMPACT FACTOR: 7.479

Papers accepted for publication:

Papers communicated for publication /under review: 1. Rai, J. and Jain, S. Pliensbachian nannofossils from Kachchh: Implications on the earliest Jurassic transgressive event on the western Indian margin, Accepted Zitteliana Journal, Germany. 2. Rai, J.; Singh, A. and Gulati, D. Bartonian age calcareous nannofossil biostratigraphy of Tanot well-1, Jaisalmer basin and its implications Submitted to the Journal of the Palaeontological Society of India and is under review. 3. Rai, J.; Malsawma, J. ; Lalrinchhana, C. ; Lalnuntluanga, P.; Ralte, V. Z. and R. P. Tiwari Nannofossil Biostratigraphy from Bhuban Fomation, Mizoram, Northeastern India and its palaeoenvironmental interpretations. Submitted to Palaeonotogical Society of India, Spl. Volume.

b) Review Papers (Please mention Co-author (s), if any, title, journal, volume, year and page

numbers):

(i) upto the last appointment/ assessment promotion in the Institute: NIL (ii) Since last appointment/assessment promotion in the Institute NIL

c) Books/ Monographs/ Catalogues (Please mention Co-author (s), if any, title, year, edition and name of the publisher:

(i) upto the last appointment/ assessment promotion in the Institute: Nil

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(ii) Since last appointment/assessment promotion in the Institute:

Rai, J. (2007) A Catalogue of Calcareous Nannoplankton from India. Diamond Jubilee Special

Publication, Birbal Sahni Institute of Palaeobotany, Lucknow, pp. 1- 77.

d) Edited Volumes (Please mention Co-author (s), if any, name of the book/journal, volume, year and name of the publisher): (i) upto the last appointment/ assessment promotion in the Institute: NIL

(ii) Since last appointment/assessment promotion in the Institute:

Refereed Proceedings volume of the International Conference on “Geo- environment Challenges Ahead” held at Jammu on 23- 25 April 2007.

e) Chapters contributed in Edited Books (Please mention Co-author (s), if any, title of the Chapter, year, name of the book, editor (s), edition and name of the publisher : i) upto the last appointment/ assessment promotion in the Institute: NIL

ii) Since last appointment/assessment promotion in the Institute: Chapter 5. Rai, J.; Ramkumar, Mu. and Sugantha, T. (2013). Calcareous nannofossils from the Ottakoil formation, Cauvery Basin, South India: Implications on age, biostratigraphic correlation and palaeobiogeography Special volume of Springer Verlag (Ed. Ramkumar) on the Sustenance of Earth Resources, Heidelberg, Germany, pp. 109- 122. Chapter 15. Mu. Ramkumar; Sugantha T. and Rai, J. (2013). Facies and textural characteristics of the Kallamedu Formation, Ariyalur Group, Cauvery Basin, South India: Implications on Cretaceous-Tertiary Boundary (KTB) events Special volume of Springer Verlag (Ed. Ramkumar) on the Sustenance of Earth Resources, Heidelberg, Germany., pp.263- 284 .

f) Popular Scientific Articles/Reports (Please mention Co-author (s), if any, title, name of the magazine/periodical, year and page numbers) :

i) Upto the last appointment/assessment promotion in the Institute :NIL 1. Rai, J. (2002) Jaisalmer jehan Kabhi Samudra lehrata tha. Samvay, C.D.R.I.: 5 – 7. 2. Rai, J. (2002) Koyala, a scientific poem published in BSIP News Letter, no. 5. 3. Rai, J. (2003) Paraganu tatha jeevan, a scientific poem published in BSIP News Letter, no. 6.

4. Rai, J. (2004) Jeevashm, a scientific poem published in BSIP News Letter, no. 7: 29. 5. Rai, J. (2004) Nannofossil, a scientific poem published in BSIP News Letter, no. 8: 46.

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6. Rai, J. (2004) Kyon aate hain bhukamp, a radio talk from All India Radio , broadcasted on 08.10. 04. 7. Rai, J. (2006) kya Andman mein adam - yugeen sabhyata vidyaman hai, Gyan – Vigyan, C.D.R.I. Hindi periodical, 20: 27-29.

ii) Since last appointment/assessment promotion in the Institute : 1. Awarded fisrt prize in Kavita pratiyogita in 2007 in Hindi pakhwara at BSIP.

2. Awarded third prize in Galti dhudo patiyogita in Hindi Pakhwara in 2007

3. Kavya path from All India Radio on 20. 03. 09.

4. Rai, J. (2011). Delivered Raio talk entitled “Kahan gaye Dinosaur” on 19.06. 2011.

5. Rai, J. (2011). Delivered Radio talk entitled “Kya hote hain Fossils” on 04. 12. 2011

6. Rai, J. (2012) Nannofossils: The Size matters and a Matter of size”delivered on 11.09. 12 in

Training on Palynology in Fossil Fuel Exploration at Birbal sahni Institute of Palaeobotany w.e.f.

10- 17 september 2012.

7. Rai, J. (2013) When did meet the twain? The Jurassic Sea with the western Indian craton?

Nannofossils the blackbox.18 October 20013, Lecture at BSIP, Lucknow.

g) Book Reviews (Please mention Co-author (s), if any, title, name of the book reviewed, name of the journal, volume, year and page numbers) :

i) Upto the last appointment/assessment promotion in the Institute: NIL

ii) Since last appointment/assessment promotion in the Institute: NIL

h) Papers presented in National/International Conferences/ Seminars/ Symposia,

i) Upto the last appointment/assessment promotion in the Institute: (1) UPADHYAY, R.; RAI, J. & SINHA, A.K. (2002) Discovery of the Bathonian _ Callovian Nnnoflora from the Eastern Karakoram Block. XVIIth Himalayan – Karakoram – Tibet Workshop, Gangtok, Sikkim. (2) RAI, J. (2002) Calcareous nannofossils from the Maniara Fort Formation (Oligocene), SW Kachchh (= Kutch), western India. 9th International Nannoplankton Association Conference, Parma, Italy (8 –14 Sept. 2002), JNR 24 (2): 153. (3) RAI, J. (2002) Early Callovian Nannofossils from Kuldhar, Jaisalmer Basin, Rajasthan, western India. 6th International Symposiun on Jurassic System (12- 22 Sept. 2002), Mondello, Sicily, Italy.

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(4) RAI, J. (2003) Nannofossils as biochronostratigraphic markers of Bartonian, Priabonian and Rupelian Stages in western India. In International Subcommission on Paleogene Stratigraphy -Symposium on the Paleogene preparing for modern life and climate, Leuven, Belgium (Aug, 25 -30, 2003). (5) RAI, J. (2005) Role of nannofossils in assessing palaeoclimate. Diamond Jubilee National Conference on Challenges in Indian Palaeobiology, BSIP, Lucknow, Nov. 2005. (6) RAI, J. (2005) Callovian transgressive event in Indian Subcontinent, Nannofossil evidence. International Seminar on Northward flight of India in the Mesozoic-Cenozoic: Consequences on biotic changes and basin evolution, Department of Geology, University of Lucknow, Lucknow, December 7-9, 2005: 72- 73. (7) Rai, J.; jaikrishna & Ojha, J. R. (2005) Late Callovian nannofossils from Jara Dome, Kutch, western India- Biochronology and calibration by ammonites. XX Indian Colloquium on Micropaleonotology & Stratigraphy, Visakhapatnam, October 2005. (8) RAI, J. (2006) Reworked Pliensbachian – Aalenian nannofossils from Jara Dome, Kutch: Early Jurassic Palaeobiogeography of western India at The XIth International Nannoplankton Association at Nebraska, U.S.A.: 84 – 85. ii) Since last appointment/assessment promotion in the Institute: (1) RAI, J. & GARG, R. (2007) Record of late Eocene (Bartonian) age calcareous nannofossils

from Dilni river section, Meghalaya, northeastern India. In International Conference on Geoenvironment: Challenges Ahead, April 23 - 25, 2007, Geology Department, Jammu University, Jammu.

(2) DESAI, B. G.; RAI, J. and PATEL, N. (2007) Belemnite Biostratigraphy of Callovian

sediments of Jara Dome, southwestern Kutch, Gujarat, XXIth Indian Colloquium on Micropalaeonotology & Stratigraphy Nov. 16 - 17, 2007, B.S.I.P., Lucknow: 26.

(3) RAI, J. (2007) Early Jurassic calcareous nannofossils from Patcham Island, Kutch, western

India. XXIth Indian Colloquium on Micropalaeonotology & Stratigraphy, Nov. 16 - 17, 2007, B.S.I.P., Lucknow: 143.

(4) RAI, J. & RAMKUMAR, M. (2007) Calcareous nannofossils from Ottakoil Formation (Late

Maastrichtian), Cauvery Basin, South India. XXIth Indian Colloquium on Micropalaeonotology & Stratigraphy, Nov. 16 - 17, 2007, B.S.I.P., Lucknow: 144 - 145.

(5) RAI, J. & SINGH, A. (2007) Significance of calcareous nannofossils in biostratigraphy and

palaeoenvironmental and Paleoclimatic interpretation. XXIth Indian Colloquium on Micropalaeonotology & Stratigraphy, Nov. 16 - 17, 2007, B.S.I.P., Lucknow: 146.

(6) RAI, J. & SINGH, A. (2008) A poster entitled “Albian age calcareous nannofossils from Tanot

Bore- well, Jaisalmer Basin in Rajasthan area, Western India” was presented In Conference on “Plant Life through the Ages”, Birbal Sahni Institute of Palaeobotany, Lucknow. Nov. 16 - 17, 2008.

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(7) RAI, J. SINGH, A. & Pandey, D. K. (2009) Early to Middle Albian age calcareous nannofossils from Pariwar Formation of Jaisalmer Basin, Rajasthan, western India and its significance. 8th International Cretaceous Symposium, University of Plymouth, U.K. (06- 12 Sept. 2009), 121 - 123.

(8) RAI, J. & SINGH, A. (2009) Reinterpretation of age and depositional environment of Pariwar

Formation in Jaisalmer Basin – A nannofossil perspective. “GEOYOUTH-09” All India Students Symposium on Geology. Dept. of Geology, Mohanlal Sukhadia University, Udaipur. (06 - 07 November,2009), 4-6.

(9) RAI, J. & ABHA (2009) Nannofossil imprints of Albian transgressive event in Indian subcontinent.

XXII Indian colloquium on Micropalaeontology and Stratigraphy. December 16-18, 2009, PG and Research Department of Geology, Tiruchirapalli: 30 - 32.

(10) RAI, J. & GARG, R. (2010) Nannofossil age constraint for Rupsi Member, Baisakhi Formation,

Jaisalmer Basin, western India. Strati 2010- “4th French” Congress on Stratigraphy, Universite Pierre et Marie Curie- UPMC, August 30 September 02, 2010, Session 15, How nannobiostratigraphy can improve the age control of stage Boundaries.

(11) RAI, J. & ABHA (2011). Palaeogeographic significance of Seribiscutun primitivum, a cold

water representative from Jaisalmer Basin, Rajasthan. National conference on “Stratigraphy, Palaeontology and Palaeoenvironment”. February 3 - 5, 2011, Department of Geology, University of Rajasthan, Jaipur.

(12) RAI, J., PRAKASH N., PANDEY, D. K., FÜRSICH F. T. AND ALBERTI, M. (2011) On the

earliest record of Bennetitalean plant fossils from the Middle Oxfordian Washtawa Formation of the Wagad region, Kachchh, Western India – ammonoid and nannofossil evidence, February 3 - 5, 2011, Department of Geology, University of Rajasthan, Jaipur.

(13) RAI, J. (2011) “Reminiscence of Jurassic climate in India recorded by calcareous

nannofossils” at the Humboldt Kolleg and International Conference “Earth Future” from 7th – 9th September 2011 at Periyar University, Salem, p. 92.

(14) RAI, J. & JAIN, S. (2012) Early Jurassic Gondwanaland breakup- A nannofossil story. DST Sponsored national level Field Workshop and Brainstorming session on “Geology of kachchh Basin, western India: Present status and Future Perspectives” Department of Earth and Environmental Science, KSKV Kachchh University, Gujarat, 26 - 29 January, 2012.

(15) RAI, J. ; MALSAWMA, J.; LALRINCHHANA, C.; LALCHAWIMAWII & RALTE, V. Z.

(2012) Nannofossil biostratigraphy from Bhuban Formation, Mizoram, Northeastern India and its palaeoenvironmental interpretations. November 28-30, 2012, 27th Himalaya- Karakoram – Tibet Workshop, Journal of the Nepal Geological Society, Kathmandu, v. 45, special issue, pp. 72 - 73.

(16) Rai, J. (2013) “When did the Jurassic Sea date the western Indian craton? Revelations by

nannofossils” 14 International Nannoplankton Association Meeting 15 - 21 September 2013, Reston, Virginia.

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(17) Garg R., Rai, J and Singh, A. (2013). Calcareous nannofossils across K/Pg boundary at Um sohryngkew, Meghalaya, Northeastern India, 14 International Nannoplankton Association Meeting 15 - 21 September 2013, Reston, Virginia.

(18) Rai, J.; Patel, S.J.; Singh, A.; Shukla, H.; Gupta, M. and Garg, S. (2013). Bathonian-

Kimmeridgian age nannofossils from Habo Dome, northeastern Kachchh, Gujarat, western India, XXIVth Indian Colloquium on Micropaleontology and Stratigraphy, 18 - 21, November 2013, Dehradun.

(19) Rai, J.; Achutan, H.; Singh A. & Nagasundaram, M. (2013). Quaternary age calcareous

nannofossils and ascidian spicules from Bay of Bengal, India, XXIVth Indian Colloquium on Micropaleontology and Stratigraphy, 18 - 21, November 2013, Dehradun.

(20) Rai, J.; Garg, S.; Singh, A.; Gupta, M.; Garg, R. & Pandey, D.K. (2013). High resolution

nannofossil – dinoflagellate and ammonite biostratigraphy from Wagad Highland, Kachchh, western India, XXIVth Indian Colloquium on Micropaleontology and Stratigraphy, 18 - 21, November 2013, Dehradun.

(21) Rai, J.; Gupta, M.; Singh A.; Garg S. & jain, S. (2013). Calcareous nannofossil-ammonite

biostratigraphy from Jumara Dome, Kachchh, western India, XXIVth Indian Colloquium on Micropaleontology and Stratigraphy, 18 - 21, November 2013, Dehradun.

(22) Rai, J.; Prasad, M.; Prakash, N.; Singh, A.; Garg, S. Gupta, M. Pandey, D.K. (2013). First

record of Fossil wood from Gangta Bet, Wagad, eastern Kachchh and its palaeoecological interpretations. National Conference on Recent Developments in Plant and earth Sciences, 28-29 November , 2013, pp. 96 - 97.

(23) Ramkumar, M.; Berner, Z.; Sugantha, T.; Rai, J. AND Garg, R. (2013). Trends of

geochemistry, relative sea level and source area weathering in the Barremian- Danian strata of the Cauvery Basin, South India: implications and relationships with the regional and global palaeoclimatic models. National Conference on Recent Developments in Plant and earth Sciences, 28 - 29 November, 2013, pp. 100.

(24) Singh A. and Rai, J. (2013). Record of southern high latitude nannotaxa at low latitude: a case

study from subsurface Late Cretaceous of Jaisalmer, western India. National Conference on Recent Developments in Plant and earth Sciences, 28 - 29 November , 2013, pp. 119.

14. Citation of research work since last appointment / assessment promotion in the Institute ( Please mention names of the scientists who have cited your publication (s) along with all relevant details) : Cited in various National and International publications.

15. Training undertaken /short term or refresher course since last appointment/assessment promotion in the Institute:

Name and type of

training/Short-term Refresher

Course

Duration Venue

Relevance to the candidate’s research activities

21

A proficiency course on “Modern Practices in Petroleum Exploration” by The Petrotech Society.

18-23 Sept. 2006

The Institute of Drilling Technology, ONGC Dehradun.

It has direct bearing on my current researches related with Academia.

Sedimentology and sequence stratigraphy

26-31 Oct. 2009 Birbal Sahni Institute of Palaeobotany, Lucknow

Principles and application of sequence stratigraphy are pertinent to my field of work.

16. Lectures/Seminars delivered or Training imparted since last appointment/assessment

promotion in the Institute: Title Date Organization where Lecture/Seminar delivered or

Training imparted (with the name (s) of trainee (s))

1.“Calcareous Nannofossils”

2. Nannofossils – Morphotaxonomy and Biostratigraphy

3. The so called equable Jurassic climate and nannofossils – The story teller. 4. “Nannnofossils: The Goliath size and David Applications ” delivered two lectures .5. “Calcareous Nannofossils”

6. When did meet the twain? The Jurassic Sea with the western Indian craton? Nannofossils the blackbox.

05-12- 2007 06-01-2009 01-05- 2010. 12 September 2011 18 October 20013

Geology Department, University of Rajasthan, Jaipur. In-House-Lecture series at Birbal Sahni Institute of Palaeobotany, Lucknow. Friday Lecture series at Birbal Sahni Institute of Palaeobotany, Lucknow MBA Programme on Petroleum Technology and management at The Institute of Management Sciences, University of Laucknow, Lucknow. Geology Department, Anna University, Chennai. Lecture at BSIP, Lucknow.

17. Theses supervised: Degree Name of Name of Title of Year Co-supervisor,

22

student University Thesis completed if any Ph.D. Ms. Abha University of

Lucknow, Lucknow

Subsurface Cretaceous calcareous nannofossil biostratigraphy from Tanot Bore Well-1 Jaisalmer Basin, Rajasthan, India

2012 Supervisor: Dr. Ajay Mishra, Department of Geology, Lucknow University

Ph.D. Ms. Surabhi Garg

BHU, Varanasi

High Resolution Integrated Nannofossil - ammonoid biostratigraphy of Wagad, Kachchh Basin, palaenvironmental and palaeobiogeographic implications

under progress

Supervisor: Dr. A.K. Jaitley, BHU

Ph.D. Ms. Mridul Gupta

BHU, Varanasi

Calcareous nannofossil – ammonite biostratigraphy from Jumara Dome, Kachchh, western India

under progress

Supervisor: Dr. A.K. Jaitley, BHU

18. Sponsored projects completed/in progress since last appointment/assessment promotion in the Institute :

Participated in a DST- Sponsored Project of Bhawani Singh G. Desai of Department of

Geology, Faculty of Science, M.S. University of Baroda, Vadodara cited below and carried out nannofossil studies from Jurassic of Jara Dome of Kutch.

Project Title Whether completed or in

progress

Duration Amount of

grant

Sponsoring agency

Co-investigator (s) if any

Member, National working group IGCP- 506 Marine and Non –marine Jurassic: Global correlation and major geologic events.

In progress

2005- 2009 Nil

GSI, Kolkata

Working members

Ichnology of the Jurassic rocks of the Jara Dome of Western Mainland Kachchh, India DST Sponsored Project No. SR/FTP/FS-48/2003

09.03.2005 -08.03.2008

Three years Nil

DST PI Bhawani Singh

G. Desai

23

19. Review/Research/Design/Feasibility Reports prepared since last appointment/assessment promotion in the Institute: Title No. of pages Agency for which

preparedCo-author, if any

Application of Palynology in Hydrocarbon Exploration of Petroliferous Basins of India Organic Matter Studies in Source Rock Analysis Palynology and Palynofacies studies: some case histories - Gap areas where BSIP can play a role” and “BSIP – offerings to Industry in Hydrocarbon Exploration Research pamphlet “Birbal Sahni Institute of Palaeobotany, Lucknow: Offering Palynology as a tool to Industry in Hydrocarbon Exploration Research”

- - - -

BSIP, Lucknow V. PRASAD, M. KUMAR, A. SINGH, J. RAI, S.K.M. TRIPATHI, B.D. SINGH& R. GARG

20. Consultancy/Contract Research/Contract Training Services rendered since last appointment/assessment promotion in the Institute: NIL Name of client

Type of service rendered

Period Amount paid by theClient to the Institute

21. Conferences/ Symposia/ Seminars/Workshops attended since last appointment /assessment

promotion in the Institute: Conference/Symposia/ Seminar/ Workshop Duration Venue In India:

Abroad: (1) 27th Himalay- Karakoram-Tibet Workshop

(28-30 Nov. 2012)

Kathmandu, Nepal

24

22. Visits abroad, if any for availing Scholarship/Fellowship/Training or under any Exchange Programme since last appointment/assessment promotion in the Institute:

Name of Scholarship/ Fellowship/ Training/ Exchange Programme

Laboratories/ Countries visited Duration

INSA Exchange Programme Natural History Museum, U.K. University College London, U.K.

21th March to18th June 2008

23. Examinerships, Memberships of Selection/Assessment Committees and other expertise,

etc. render to other origination since last appointment/ assessment promotion in the Institute:

Academic/Professional

expertise Name of the Organization Year

Examinership of M.Sc. Geology IV semester exam

Mizoram University

July 02, 2012

Co-ordinator International Conference on Geology and Hydrocarbon Potential of the Neoproterozoic-Cambrian Basins in India, Pakistan and the Middle East

Geology Department, University of Jammu, Jammu

Feb. 20-21, 2008

Member Committee for priced publication

BSIP, Lucknow -

Member Programming Committee, in Founder’s Day Celebrations and National Conference

Nov. 14-17, 2007

Member Abstract Publication Committee in XXIth Indian Colloquium on Micropalaeontology and Stratigrapny

BSIP, Lucknow Nov. 16-17, 2007

24. Memberships/Fellowships of scientific/ professional bodies/ societies/ academies: Scientific/professional Body/society/academy

Year of admission whether the Membership/ Fellowship is continue

Fellow of the Journal of the Palaeontological Society of India, Lucknow.

1986

Member Executive council, Fellow, Continued

Indian Association of 1982 Life Member

25

Palynostratigraphers, Lucknow South Asian Association of Economic Geologists, Dhanbad

1997 Founder Member

Member International Nannoplankton Association

1984 Continued

Paleobotanical Society 2013 Life Member 25. Prizes/Honours/Medals/Awards/Distinctions, if any, received in recognition of the

research work: Prizes/Honours/Medals/Awards/Distinctions Year Upto the last appointment/assessment promotion in the Institute

Since last appointment/assessment promotion in the Institute Examinership of M.Sc. Geology IV semester exam at Mizoram University Member Executive Council The Palaeontological Society of India, Centre of Advanced Studies in Geology, University of Lucknow, Lucknow Chairperson Technical Session IV entitled “Evolution, Extinctions, Biostatigraphy” at XXIII Indian Colloquium on Micropalaeontology and Stratigraphy and International Symposium on Global Bioevents in the Earth History Co- chaired a Technical session in Venkatgiri Auditorium, Bangalore Chaired Technical Session at the National Conference on “Stratigraphy, Palaeontology and Palaeoenvironment” in the Department of Geology, University of Rajasthan, Jaipur Delivered keynote lecture “Reminiscence of Jurassic climate in India recorded by calcareous nannofossils” at the Humboldt Kolleg and International Conference “Earth Future” at Periyar University, Salem, p. 92 Chaired Technical session III in XXIIth Indian Colloquium on Micropalaeontology and Stratigraphy, Tiruchirapalli, Tamilnadu Co-ordinator International Conference on Geology and Hydrocarbon Potential of the Neoproterozoic-Cambrian Basins in India, Pakistan and the Middle East, Geology Department, University of Jammu, Jammu Member Programming Committee, in Founder’s Day and two

July 02, 2012 2012 9- 11 December 2011 10th December, 2011

3rd to 5th February 2011 7th – 9th September 2011 16-18 December 2009 Feb. 20-21, 2008 Nov. 14-17, 2007

26

National Conferences Member Abstract Publication Committee in XXIth Indian Colloquium on Micropalaeontology and Stratigrapny Awarded Ist prize in Hindi Kavita lekhan in Hindi Pakhwara at BSIP, Lucknow Member of Nirnayak mandal for class IX- XII Nibandh pratiyogita on Water and Life at BSIP on National Science Day Member National Advisory Committee in “The 9th International Congress on Jurassic System” scheduled to be held in Department of Geology, University of Rajasthan, Jaipur

Nov. 16-17, 2007 2007 2007 January 06 - 09, 2014

26. Involvement in the administrative/organizational activities of the Institute since last appointment/assessment promotion in the Institute:

• Physical verification of annual stock of price publication, BSIP from 2007- 2013. • Current Convener Electron Microscopy Committee • Current Member Microscope Maintenance and Distribution Committee. • Current Convener Staff Welfare Committee

27. Any other information which is relevant for considering the candidate’s case for assessment promotion: Nannofossil researches from late Triassic – Quaternary age marine sediments of both surface and subsurface sequences have been carried out by me from past over three decades. Significant data providing nannofossil biostratigraphy have been generated from stratigraphically critical horizons of Indian sedimentary basins (e.g. Quaternary of Harshad estuary, Gujarat; Bay of Bengal; Neogene of Mizoram and Andaman – Nicobar Islands; Oligocene of Kachchh; Eocene of Kachchhh and Assam, Late Cretaceous of Lameta Formation, Bagh, central India, Jaisalmer and Cauvery basins; early Cretaceous of Kachchh and Rajasthan basins, Jurassic of Kachchh, Jaisalmer and Karakoram Block, late Triassic of Ladakh). Current finding of precise Pliensbachian age earliest epeiric transgressive event in Kachchh Basin is envisaged by nannofossil studies. It has wide palaeogeographical implications. It speaks of break-up of Gondwanaland by ca. 12 my earlier and thereby opening of an arm of sea (the Ethiopian gulf) leading to inundation of western Indian craton. Presently I am engaged in erecting an integrated classical Jurassic nannofossil – ammonite biostratigraphic zonation of western India and its palaeobiogeographical implications with respect to stratotypic European Jurassic nanno- assemblages biozonation. My visit under INSA exchange programme to U.K. has greatly benefitted me in studying European Jurassic type material and consulting rare nannofossil literature. Exchange of scientific ideas and discussions with the U.K. scientists (Jeremy Young, Paul Bown, Jackie Lees, Susan Fiest Bukhardt) have helped me for my ongoing Jurassic researches on Indian material. Integrated Jurassic nannofossil- ammonite- dinoflagellate cyst studies will be helpful in erecting precise zonal scheme for mixed Tethyan province to which the Indian subcontinent was a part during this time slice. The nannofossil expertise has a direct bearing for dating marine sequences and is most useful

27

onboard ships in a deep sea drilling vessel for which India is venturing in petroleum exploration. My futuristic plan of work is to develop manpower/ specialists for nannofossil studies which may help in establishing BSIP a national centre of excellence for nannofossil researches and a consultancy centre as well. I request you Sir, assessing my research output, to kindly consider my case for award of two advance increments, which would compensate and provide encouragement. Date: 20.12.13 Signature of the Candidate

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*For correspondence. (e-mail: jyotsana_rai@yahoo.com)

supported by Das and Scholz5, who used the dynamical model and found that ruptures that initiate in a shallow (low stress) region are prevented from propagating into deeper (high strength) regions. Instead, ruptures that ini-tiate in deeper (high-stress region) are capable of propa-gating through the entire ‘schizosphere’. This view is supported by prediction from friction data coupled with stability analysis14 that earthquakes should not nucleate within the upper region of mature fault zones15, i.e. 1–4 km in this case. Assuming that frequency–magnitude statistics can be used to estimate probabilities of a small rupture initiation growing into a larger earthquake, Mori and Abercombie16 showed that a small (magnitude 2) rup-ture initiated at a depth of 9–12 km is 18 times more likely to grow into a magnitude 5.5 or larger event com-pared to the small rupture initiation at shallower depth of 0–3 km. We conclude based on theoretical and experi-mental considerations, that earthquakes in Koyna region initiate at deeper level and propagate upward along a fault plane surface. These results clearly demonstrate that the earlier proposed hypothesis that earthquakes in Koyna region nucleate at shallow depth and migrate downward is not tenable and hence the earthquake prediction model must be discarded. The results call for developing a new model for nuclea-tion of earthquakes in Koyna region with better located hypocentres and supported by appropriate dynamical simulation of geo-mechanical systems using accurate description of 3D geometry and mechanical property of the fault systems, hitherto lacking despite over five decades of geophysical investigation in the region.

1. Ohnaka, M., Nonuniformity of the constitutive law parameters for shear rupture and quasistatic nucleation to dynamic rupture: a physical model of earthquake generation processes. Proc. Natl. Acad. Sci. USA, 1996, 93, 3795–3802.

2. Mandal, P. et al., Method of short term forecasting of moderate sized earthquakes. US Patent 2003/0182065 A1, September 2003.

3. Rastogi, B. K. and Mandal, P., Foreshock and nucleation of small to moderate sized Koyna earthquakes (India). Bull. Seismol. Soc. Am., 1999, 89, 829–836.

4. Abercrombie, R. E. and Mori, J., Occurrence, patterns of fore-shocks to large earthquakes in the western United States. Nature, 1997, 381, 303–307.

5. Das, S. and Scholz, C. H., Why large earthquakes do not nucleate at shallow depth? Nature, 1983, 305, 621–623.

6. Rai, S. S., Singh, S. K., Sarma, P. V. S. S., Srinagesh, D., Reddy, K. N. S., Prakasam, K. S. and Satyanaryana, Y., What triggers Koyna region earthquakes? Preliminary results from seismic tomography digital array. Proc. Indian Acad. Sci. (Earth Planet. Sci.), 1999, 108, 1–14.

7. Kissling, E., Geotomography with local earthquake data. Rev. Geophys., 1988, 26, 659–698.

8. Waldhauser, F. and Ellsworth, W. L., Double difference location algorithm: method and application to Northern Hayward fault, California. Bull. Seismol. Soc. Am., 2000, 90, 1353–1368.

9. Waldhauser, F., HypoDD – a program to compute double differ-ence hypocenter locations. US Geol. Surv. Open file report, 01-113, 2001, p. 113.

10. Got, J. L., Frechet, J. and Klein, F. W., Deep fault geometry inferred from multiple relative relocations beneath the south flank of Kilauea. J. Geophys. Res., 1994, 99, 15375–15386.

11. Page, C. C. and Saunders, M. A., LSQR: an algorithm for sparse linear equation and sparse least squares. ACM Trans. Math. Soft-ware, 1982, 8, 43–71.

12. Mandal, P., Rastogi, B. K. and Sarma, C. S. P., Source parameters of Koyna earthquakes, India. Bull. Seismol. Soc. Am., 1998, 88, 833–842.

13. Macelwane, J., Problems and progress on the geological– seismological front. Science, 1936, 83, 193–198.

14. Rice, J. R. and Ruina, A. L., Stability of steady and frictional slip-ping. J. Appl. Mech., 1983, 105, 343–349.

15. Marone, C. and Scholz, C. H., The depth of seismic faulting and the upper transition from stable to unstable slip regimes. Geophys. Res. Lett., 1988, 15, 621–624.

16. Mori, J. and Abercrombie, R. E., Depth dependence of earthquake frequency–magnitude distribution in California. Implication of rupture initiation. J. Geophys. Res., 1997, 102, 15081–15090.

ACKNOWLEDGEMENTS. S.S.R. is supported by J.C. Bose Fellow-ship from DST, New Delhi. Field observation was supported by a research project from DST. We thank the anonymous reviewer for critical suggestions that helped improve the manuscript. Received 5 August 2013; revised accepted 24 September 2013

Early to Middle Albian age calcareous nannofossils from Pariwar Formation of Jaisalmer Basin, Rajasthan, western India and their significance Jyotsana Rai1,*, Abha Singh1 and Dhirendra Kumar Pandey2 1Birbal Sahni Institute of Palaeobotany, 53, University Road, Lucknow 226 007, India 2University of Rajasthan, Jaipur 302 004, India Early–Middle Albian calcareous nannofossil assem-blage comprising 55 species has been recovered from the Pariwar Formation, Jaisalmer Basin, western India. The nannofossils are moderate to well-preserved and are calibrated with Early–Middle nannofossil zones CC7–CC8 of Albian age. The present record of nannofossils indicates a marine depositional environ-ment with good connection to the open ocean for the Pariwar Formation. Presence of species, Seribiscutum primitivum in small numbers in surface sediments of Pariwar Formation and its common occurrence in coeval subsurface succession of Tanot Well-1 is the first record from the Cretaceous of Western India, which was located at ~30°S of the equator during mid-Cretaceous. S. primitivum is considered as cold-water, high-latitude taxa. Its presence in the Jaisalmer Basin

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suggests influx of cooler water currents from southern high latitudes during Albian time. Its co-existence with warm-water, wide-canal-bearing robust Tethyan nannoconids in the Jaisalmer assemblage suggests mixing of cold water masses with the warm waters in the western margin of the Indian subcontinent during Albian. Keywords: Calcareous, cold and warm waters, deposi-tional environment, sedimentary succession. THE Lower Cretaceous sedimentary succession exposed in the Jaisalmer Basin comprises of arenaceous Pariwar

Formation (‘Neocomian’) and calcareous Abur Formation (Early Aptian–Middle Albian; Figure 1). Although plant fossils, e.g. leaf impressions and wood-fossils1,2 are known from the Pariwar Formation, no marine mega or micro fauna are yet reported. Pariwar Formation has been considered as deposit of non-marine or estuarine setting and assigned a broad ‘Neocomian’ age. The formation is sandwiched between ammonite-bearing Bhadasar Forma-tion (Tithonian) and Abur Formation (Early Aptian–Middle Albian). In the subsurface, however, the sandy succession considered equivalent of the Pariwar Forma-tion is known to contain agglutinated foraminifera3,4 and

Figure 1. Geological map of the Jaisalmer Basin (modified after Das Gupta11 and Singh31), showing location of samples.

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datable calcareous nannofossils of Albian age5. In the present communication, we record a rich and diverse calcareous nannofossil assemblage from sandy calcareous shale beds within the poorly sorted, fine-grained sand-stone to pebbly sandstone succession, which provides evidence for age and depositional environment of the Pariwar Formation. Regional and geological studies of Jaisalmer area have been carried out by several workers6–13. The Pariwar For-mation is named after the Pariwar village (27°14′30″N; 70°44′30″E) and is predominantly made up of medium to coarse-grained sandstone showing large-scale cross-bedding. There are few beds of fine-grained sediment. Filicales, Pteridosperms, Cycadales, Bennettitales, Gink-goales and Coniferales wood fossils and fossil leaf im-pressions are present in some horizons, which indicates the existence of climatic conditions conducive for luxuri-ant growth of plants1,2. During early part of the Late Cretaceous, the Jaisalmer area was situated 30°S of the equator surrounded by sea2. Hence it is inferred that dur-ing this time, subtropical coastal climate must have pre-vailed in Jaisalmer area with hot summers, cool winters and good amount of rainfall, and the fossil plant remains are testimony to this. The riverine system washed the plant debris into marine coastal area. The Pariwar Forma-tion consists of alternating bands of highly bioturbated and non-bioturbated sediments, suggesting alternating periods of slow and rapid sedimentation. Some of the cross-bedded sandstones show bipolar cross-bedding, in-dicating influence of tidal currents. Deposition of Pariwar Formation took place in high-energy coastal setting with tidal influence. Nine samples were collected from (27°10′54.6″N, 70°34′08.8″E) Jaisalmer–Ramgarh Road section near 11 km milestone at Sanu (Figures 2 and 3). Samples were processed following conventional method of nannofossil slide preparation14. The slides are housed in the museum of Birbal Sahni Institute of Palaeobotany, Lucknow (slide no. 13929-13931). Only one sample (no. 9/9) was productive and studied under Leitz polarizing micro-scope. The documented taxa are illustrated in Figures 4 and 5. Zonal classification of mid-latitude has been followed here because of the mid-latitudinal position of India dur-ing Albian following the classification proposed by Sissingh15,16 and Mutterlose17,18. The recovered nannofos-sil assemblage is assigned early to middle Albian age on the basis of presence of Prediscosphaera columnata, a cosmopolitan marker, whose FAD marks the base of lower Albian (base of CC8a) and Tranolithus orionatus, which demarcates the CC8a/b boundary. In Tethyan realm the FAD of T. orionatus lies between CC8a/b boundary of lower/middle Albian age in the Indian Ocean (Figure 6). Besides, the record of Arkhangelskiella ante-cessor (Albian), Owenia hillii (Albian–Cenomanian), Zeugrhabdotus erectus (Albian–Cenomanian), Eprolithus

floralis (Aptian-Campanain), Eiffellithus gorkae (Albian-Maastrichtian) places the assemblage safely within CC8a/b P. columnata zone of early–middle Albian age

Figure 2. Photograph showing productive sample site.

Figure 3. Composite litholog of the Pariwar Formation, Jaisalmer Basin (after Singh31).

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Figure 4. 1a, b, Arkhangelskiella antecessor Burnett, 1998b. 2a, b, Cribrosphaerella ehrenbergii (Arkhangelsky, 1912) Deflandre in Piveteau, 1952. 3a, b, Biscutum constans (Górka, 1957) Black in Black and Barnes, 1959. 4a, b, B. coronum Wind and Wise in Wise and Wind, 1977. 5a, b, Discorhabdus ignotus (Górka, 1957) Perch-Nielsen, 1968. 6a, b, Seribiscutum primitivum (Thierstein, 1974) Filewicz et al. in Wise and Wind, 1977. 7a, b, Rucinolithus windleyae Rutledge and Bown, 1996. 8a, b, Owenia hillii Crux, 1991b. 9a, b, Calculites obscurus (Deflandre, 1959) Prins and Sissingh in Sissingh, 1977. 10a, b, Calculites sp. 11a, b, Gen et sp indet 1. 12a, b, Gen et sp indet 2. 13a, b, Isocrystallithus compactus Verbeek, 1976b. 14a, b, Ceratolithoides sp. 15a, b, Chiastozygus litterarius (Górka, 1957) Manivit, 1971. 16a, b, Rhabdophidites parallelus (Wind and Cepek, 1979) Lambert, 1987. 17a, b, Tranolithus orionatus (Reinhardt, 1966a) Reinhardt, 1966b. 18a, b, Zeugrhabdotus bicrescenticus (Stover, 1966) Burnett in Gale et al., 1996. 19a, b, Z. embergeri (Noël, 1958) Perch-Nielsen, 1984. 20a, b, Z. erectus (Deflandre in Deflandre and Fert, 1954) Reinhardt, 1965. 21a, b Retecapsa ficula (Stover, 1966) Burnett, 1998b. 22a, b, R. surirella (Deflandre and Fert, 1954) Grün in Grün and Allemann, 1975. 23a, b, Helenea chiastia Worsley, 1971. 24a, b, Eiffellithus gorkae Reinhardt, 1965. 25, 26a, b, Faviconus multicolumnatus Bralower, 1989 in Bralower et al., 1989. 27, 28, Faviconus sp. 29, Nannoconus sp. 30a, b, Nannoconus circularis Deres and Achéritéguy, 1980. (cf. Mutterlose17, Figure 6). It corresponds to Chiastozy-gus litterarius zone CC7b P. columnata zone CC8 of Sissingh15, which in turn corresponds to NC8/9 zones of Bown et al.19 and the environment of deposition is dedu-

ced as coastal marine. Cyclagelosphaera margerelii Noël, 1965; Faviconus multicolumnatus Bralower, 1989 in Bralower et al., 1989; Tubodiscus jurapelagicus (Worsley, 1971) Roth, 1973 are reworked forms present

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Figure 5. 1a, b, Nannoconus elongatus Brönnimann, 1955. 2a, b, N. multicadus Deflandre and Deflandre-Rigaud, 1959. 3a, b, Epro-lithus floralis (Stradner, 1962) Stover, 1966. 4a, b, Farhania varolii (Jakubowski, 1986) Varol, 1992. 5a, b, Micula infracretacea Thier-stein, 1973. 6a, b, M. staurophora (Gardet, 1955) Stradner, 1963. 7a, b, Radiolithus planus Stover, 1966. 8a, b, ? Uniplanarius sp.1. 9a, b, Uniplanarius sp.2. 10a, b, Prediscosphaera columnata (Stover, 1966) Perch-Nielsen, 1984. 11a, b, Prediscosphaera sp. 12a, b, Cylin-dralithus nudus Bukry, 1969. 13a, b, Manivitella pemmatoidea (Deflandre in Manivit, 1965) Thierstein, 1971. 14a, b, Tubodiscus jurape-lagicus (Worsley, 1971) Roth, 1973. 15a, b, Cyclagelosphaera margerelii Noël, 1965. 16a, b, C. reinhardtii (Perch-Nielsen, 1968) Romein, 1977. 17a, b, C. rotaclypeata Bukry, 1969. 18a, b, Diazomatolithus lehmanii Noël, 1965. 19a, b, D. cf. D. lehmanii Noël, 1965. 20a, b, 21a, b, Watznaueria barnesae (Black, 1959) Perch-Nielsen, 1968. 22a, b, Watznaueria sp. 23a, b, Laguncula pitcherensis Rai, 2006. 24a, b, Rhagodiscus asper (Stradner, 1963) Reinhardt, 1967. 25a, b, Gen et sp indet 2. 26a, b, Gen et sp indet 3. 27a, b, Gen et sp indet 4. 28a, b, Thoracosphaera operculata Bramlette and Martini, 1964.

in the assemblage. Presence of mid-latitude nannoconids of epicontinental Tethyan affinity in the assemblage indi-cates warm water condition20. On the other hand, Seribis-cutum primitivum, a bipolar, high-latitude, cold-water Austral form is also present21. Record of Biscutum constans

and Zeugrhabdotus erectus indicates surface water, nutri-ent-rich upwelling conditions. The recorded nannofossil assemblage from the Pariwar Formation is dominated by the forms indicating coastal marine set-up. Similar nannofossils are known from Bhuj

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Figure 6. Correlation of nannofossil assemblage with different nannofossil zones and ammonite zones.

Figure 7. Surface water circulation, upwelling areas and atmospheric pressure distribution in the Mid-Cretaceous Atlantic and Indian Oceans (modified after Roth and Krumbach32).

Member of Umia Formation in the Kachchh Basin22,23, western India, which is also deposited in coastal marine setting. This assemblage resembles the one recorded from

Cauvery Basin, east coast of India, which is also a coastal marine deposit24,25. The dominant nannofossils of the Pariwar Formation are of Tethyan affinity. It may be

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pointed out that the nannofossils also exhibit strong pro-vincialism, similar to ammonite, belemnite, bivalve, brachiopods and foraminifera during the Cretaceous26. Cold water nannofossil species S. primitivum is known to show bipolar high-latitude distribution but is restricted to latitudes greater than 30°, viz. 40–50°N and 35–60°S (ref. 17) or 40–60°N and 40–70°S (ref. 18). S. primitivum is also recorded from coeval Cauvery Basin, east coast of India25. It is present in small numbers in the Albian age surface outcrop of Pariwar Formation. It also occurs in small numbers in Albian onwards samples from the Tanot #1 borehole of the Jaisalmer Basin5. The rare occurrence of Rhagodiscus asper in the assemblage substantiates cool surface water temperature27. The assemblage also shows broad-canal nannoconids, which indicates warm-ing in the Tethyan Zone. The Nannoconus spp. are also recorded from Cauvery Basin24,25 (Figure 7). The present nannofossil record from the Pariwar Formation in western India provides evidence of warm-water conditions domi-nated by Tethyan connection. However, cold-water currents from mid-latitudes located south of the Tethys Sea influenced the area intermittently. Influence of the cold-water currents in the Kachchh Basin during the Call-ovian–Oxfordian is indicated by the study of oxygen iso-topes in Belemnites28. It is concluded that the calcareous nannofossil assem-blage comprising 55 species suggests Early to Middle Albian age for the Pariwar Formation. The nannofossil forms which dominate in the assemblage indicate coastal marine environment. The assemblage is dominated by warm-water forms of Tethyan affinity including nanno-conids. Nannoconus spp. usually prefer warm water based on their high abundance in low-latitude locations29. It is suggested that Nannoconus was a deep-dwelling taxon that flourished with a deep-nutricline and marked oligotrophic conditions in surface waters30. Co-occurrence of S. primitivum, a bipolar, high-latitude form from Jais-almer Basin, Middle Albian-latest campanian indicates that cooler currents were present intermittently from Al-bian to latest Campanian, allowing the high-latitude spe-cies to migrate to lower latitudes (30–15°S) and reach the near-equatorial zone. The presence of warm (nannoco-nids) and cold water (S. primitivum) nannofossil forms during Albian is also reported from the Cauvery Basin, east coast of India25, which indicates influence of cold-water currents from the south on both east and west coasts of the Indian subcontinent.

1. Maheshwari, H. K. and Singh, N. P., On some plant fossils from the Pariwar Formation, Jaisalmer Basin, Rajasthan. Palaeo-botanist, 1974, 23, 116–123.

2. Guleria, J. S. and Shukla, A., Occurrence of a conifer wood in the desert of Rajasthan and its climatic significance. Geophytology, 2008, 37, 81–85.

3. Singh, N. P., Mesozoic–Tertiary biostratigraphy and biogeochro-nological datum planes in Jaisalmer Basin, Rajasthan. In XVI

Indian Colloquium on Micropalaeontology and Stratigraphy, Dehradun, 1996, pp. 63–89.

4. Bhandari, A., Phanerozoic stratigraphy of western Rajasthan Basin: a review. In Geology of Rajasthan: Status and Perspective (A. B. Roy Felicitation Volume) (ed. Kataria, P.), Proceedings of a Seminar, Department of Geology, Mohan Lal Sukhadia Univer-sity, Udaipur, 1999, pp. 126–174.

5. Rai, J., Singh, A. and Garg, R., Calcareous nannofossils of Albian age from Tanot Well-1, Jaisalmer Basin, Rajasthan and its palaeo-biogeographic significance. J. Palaeontol. Soc. India, 2013, 58(1), 67–73.

6. Oldham, R. D., Preliminary notes on the geology of northern Jaisalmer. Rec. Geol. Surv. India, 1886, 19, 157–160.

7. La Touche, T. H. D., Geology of western Rajputana. Mem. Geol. Surv. India, 1902, 35, 1–116.

8. Ghosh, P. K., Western Rajputana – its tectonic and minerals including evaporites. In Proceedings of Symposium on Rajasthan Desert, Bulletin of National Institute of Science, India, 1952, vol. 1, pp. 101–136.

9. Swaminathan, J., Krinshnamurthy, J. G., Verma, K. K. and Chan-diak, G. J., General geology of Jaisalmer area, Rajasthan. In Pro-ceedings of the Symposium of Development in Petroleum Resources of Asia and the Far East, Mineral Resources Develop-ment, Bangkok (ECAFE, UN), 1959, Ser. 10.

10. Narayanan, K., Stratigraphy of the Rajasthan Shelf. In Proceed-ings of the Symposium on Problems of the Indian Arid Zones, Government of India Publication, 1964, pp. 92–100.

11. Das Gupta, S. K., Revision of the Mesozoic–Tertiary stratigraphy of the Jaisalmer Basin Rajasthan. Indian J. Earth Sci., 1975, 2, 77–94.

12. Pareek, H. S., Basin configuration and sedimentary stratigraphy of western Rajasthan. J. Geol. Soc. India, 1981, 22, 517–527.

13. Pandey, D. K., Choudhary, S., Bahadur, T., Swami, N. and Sha, J., A review of the Lower–lowermost Upper Jurassic lithostratigra-phy of the Jaisalmer Basin, western Rajasthan, India – an implica-tion on biostratigraphy. Vol. Jurassica, 2012, X, 61–82.

14. Bown, P. R. and Young, J. R., Techniques. In Calcareous Nanno-fossil Biostratigraphy (ed. Bown, P. R.), British Micropalaeontologi-cal Society Series, Chapman & Hall, London, 1998, pp. 16–28.

15. Sissingh, W., Biostratigraphy of Cretaceous calcareous nanno-plankton. Geol. Mijnbouw, 1977, 56, 37–65.

16. Sissingh, W., Microfossil biostratigraphy and stage-startotypes of the Cretaceous. Geol. Mijnbouw, 1978, 57, 433–440.

17. Mutterlose, J., Lower Cretaceous nannofossil biostratigraphy of northwestern Australia (Leg 123). Proc. Ocean Drill. Prog. Sci. Results, 1992, 123, 343–368.

18. Mutterlose, J., Biostratigraphy and palaeobiogeography of Early Cretaceous calcareous nannofossils. Cretaceous Res., 1992, 13, 167–189.

19. Bown, P. R., Rutledge, D. C., Crux, J. A. and Gallagher, L. T., Lower Cretaceous. In Calcareous Nannofossil Biostratigraphy (ed. Bown, P. R.), British Micropalaeontological Society Series, Chapman & Hall, London, 1998, pp. 86–131.

20. Tremolada, F., Bornemann, A., Bralower, T. J., Koeberl, C. and van de Schootbrugge, B., Paleoceanographic changes across the Jurassic/Cretaceous boundary: The calcareous phytoplankton response. Earth Planet. Sci. Lett., 2006, 241, 361–371.

21. Kulhanek, D. K. and Wise, S. W., Albian calcareous nannofossils from ODP Site 1258, Demerara Rise. Rev. Micropaleontol., 2006, 49, 181–195.

22. Rai, J., Discovery of nannofossils in a plant bed of the Bhuj Mem-ber, Kutch and its significance. Curr. Sci., 2006, 91, 519–526.

23. Rai, J., Nannofossil assemblage in Kutch: Response. Curr. Sci., 2007, 92, 572–573.

24. Jafar, S. A. and Rai, J., Discovery of Albian nannoflora from type Dalmiapuram formation, Cauvery Basin, India – palaeoceano-graphic remarks. Curr. Sci., 1989, 58, 358–363.

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*For correspondence. (e-mail: rajivksaxena@hotmail.com)

25. Kale, A. S. and Phansalkar, V. G., Nannofossil biostratigraphy of the Utatur Group, Trichinopoly District, South India. Mem. Sci. Geol., 1992, 43, 89–107.

26. Bornemann, A., Aschwer, U. and Mutterlose, J., The impact of calcareous nannofossils on the pelagic carbonate accumulation across the Jurassic–Cretaceous boundary. Palaeogeogr., Palaeo-climatol., Palaeoecol., 2003, 199, 187–228.

27. Erba, E., Mid-Cretaceous cyclic pelagic facies from the Umbrian–Marchean Basin: what do the nannofossils suggest? INA Newsl., 1987, 9, 52–53.

28. Fürsich, F. T., Singh, I. B., Joachimski, M., Krumm, S., Schlirf, M. and Schlirf, S., Palaeoclimate reconstructions of the Middle Jurassic of Kachchh (western India): an integrated approach based on palaeoecological, oxygen isotope, and clay mineralogical data. Palaeogeogr., Palaeoclimatol., Palaeoecol., 2005, 217, 289–309.

29. Street, C. and Bown, P. R., Palaeobiogeography of Early Creta-ceous (Berriasian–Barremian) calcareous nannoplankton. Mar. Micropaleontol., 2000, 39, 265–291.

30. Erba, E., Nannofossils and superplumes: the early Aptian ‘nanno-conids crisis’. Paleoceanography, 1994, 9, 483–501.

31. Singh, N. P., Relevance of laboratory studies in geological modeling and field geology; Jaisalmer field guide. IMD, ONGC, Dehradun, 1999, pp. 1–25.

32. Roth, P. H. and Krumbach, K. R., Middle Cretaceous calcareous nannofossil biogeography and preservation in the Atlantic and Indian Oceans: implications for palaeoceanography. Mar. Micro-paleontol., 1986, 10, 235–266.

ACKNOWLEDGEMENTS. We thank Prof. Sunil Bajpai, Director, Birbal Sahni Institute of Palaeobotany (BSIP), Lucknow for providing facility and encouragement. We also thank Prof. I. B. Singh, Geology Department, University of Lucknow for constructive sedimentological discussions that helped improve the manuscript. We also thank Drs Ra-hul Garg, Vandana Prasad, Biswajeet Thakur of BSIP for help. Received 29 May 2013; revised accepted 3 October 2013

Heterogeneity of reticulocyte population in mouse peripheral blood Nitin Bhardwaj1 and Rajiv K. Saxena2,* 1School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067, India 2Faculty of Life Sciences and Biotechnology, South Asian University, New Delhi 110 021, India Reticulocytes constitute about 1–6% of total blood erythrocyte in mice and their numbers may be upregulated markedly in a variety of situations like treatment with erythropoietin and induction of anae-mia, etc. Reticulocytes originate in the bone marrow from erythroblasts by the process of nuclear extru-sion, and are released into the blood where they further mature into erythrocytes. From blood cells,

reticulocytes may be isolated using discontinuous Per-coll density gradient (DPDG) fractionation. Highly enriched reticulocyte preparations are obtained from the low buoyant density cellular fraction from DPDG and such enriched cell preparations have as such been used extensively as a source of purified blood reticulo-cytes in many studies. The possibility of presence of reticulocytes in other cell fractions of higher buoyant densities has, however, not been examined. In the pre-sent study, we have fractionated mouse blood cells on a five-layered discontinuous DPDG and the presence of reticulocytes was monitored in each fraction by staining for Ter-119 (transferrin receptor) and CD71 markers that together are specific markers for blood-derived reticulocytes. Our results indicate that only 16% of the blood reticulocytes were present in the low buoyant density DPDG fraction, the rest being dis-tributed in heavier DPDG fractions. Expression levels of some important functional and phenotypic reticulo-cyte markers like CD47 (integrin associated protein), CD147 (basigin), cellular calcium levels as well as RNA contents were compared for reticulocyte popula-tions derived from different DPDG fractions. Our re-sults show significant differences in the expression of these markers in reticulocyte populations of different buoyant densities and indicate that the reticulocytes isolated from low buoyant density fractions of blood cells may represent only a minor subpopulation of blood reticulocytes. Keywords: Buoyant density, erythrocytes, mouse blood cells, reticulocytes. INBRED C57Bl/6 male mice (8–12 weeks old, 20–25 g body wt) were used throughout this study as the source of blood cells. Animals were obtained from the National Institute of Nutrition, Hyderabad and maintained in the animal house facility at Jawaharlal Nehru University (JNU), New Delhi using standard environmental condi-tions. All the experimental protocols were approved by JNU Institutional Animal Ethics Committee. For prepar-ing a discontinuous Percoll density gradient (DPDG), Percoll (Sigma-Aldrich, India) solutions with mean buoy-ant densities 1.06500, 1.06805, 1.07465, 1.08200 and 1.08705 g/ml were prepared in accordance with the manufacturer’s instructions1. Discontinuous five-step gra-dients were prepared by superimposing 2 ml of each den-sity layer in 17 × 100 mm polypropylene centrifuge tubes. Blood was collected in PBS in the presence of EDTA (5 mM) and washed three times with ice-cold normal saline containing 10 mM HEPES buffer (pH 7.4) and 1% FBS. Mouse erythrocytes (1 ml, 20% hematocrit) were layered on the Percoll gradients followed by centri-fugation (4100 rpm, 30 min at 4°C). Six fractions were collected carefully starting from the top. The cells in each fraction were washed with PBS, suspended in 1 ml of PBS and cell recovery determined by cell counting on hemocytometer.

Do the large carbon isotopic excursions in terrestrial organic matteracross Paleocene–Eocene boundary in India indicate intensificationof tropical precipitation?

A. Samanta a, M.K. Bera b, Ruby Ghosh d, Subir Bera d, Timothy Filley e,f, Kanchan Pande g, S.S. Rathore h,Jyotsana Rai c, A. Sarkar a,⁎a Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur 721 302, Indiab Indian Institute of Science Education and Research, Kolkata 741 252, Indiac Birbal Sahni Institute of Palaeobotany, Lucknow 226007, Indiad Department of Botany, Calcutta University, Kolkata 700 019, Indiae Department of Earth and Atmospheric Sciences, Purdue University, West Lafayette 47907, USAf Purdue Climate Change Research Center, Purdue University, West Lafayette 47907, USAg Department of Earth Sciences, Indian Institute of Technology, Mumbai 400076, Indiah KDM Institute of Petroleum Exploration, Dehradun 248195, India

a b s t r a c ta r t i c l e i n f o

Article history:Received 19 February 2013Received in revised form 3 July 2013Accepted 8 July 2013Available online 21 July 2013

Keywords:Tropical terrestrial Paleocene–Eocene ThermalMaximumEocene hyperthermalsCarbon isotope excursionHydrological cycle

Five distinct transient warming (hyperthermal) events (Paleocene–Eocene Thermal Maximum [PETM],H1/ETM2/ELMO, H2, I1, and I2), marked by negative carbon isotope excursions (CIEs) occurred between LatePaleocene and Early Eocene (~56 to 52 Ma) interval. However, not many records of either the PETM or definitiveEarly Eocene Hyperthermals (EEHs) are yet available from terrestrial realm in the tropics except two neo-tropicalsections of Colombia and Venezuela (Jaramillo et al., 2010). Therefore, response of the tropical biosphere to thesewarming events is not verywell known. Here we report high resolution carbon isotope (δ13C) chemostratigraphy,biomarker, calcareous nannofossils, and pollen data from the Cambay shale Formation of Western India(paleolatitude ~ 5°S), which show complete preservation of all the above CIE events including the PETM, hithertounknown from tropical terrestrial record. Comparatively largermagnitudes of CIEs for all the hyperthermal events(the PETM and EEHs) point towards a possible intensification of precipitation during the PETM and all the earlyEocene hyperthermal/CIE events. This inference is supported by data of lignin phenols and presence of tropicalrain forest elements spanning the entire time period ~56–52 Ma and suggest that higher organic burial and soilerosion favored deposition of thick lignitic seams as a consequence of high tropical precipitation.

© 2013 Elsevier B.V. All rights reserved.

1. Introduction

Earth's surface experienced a series of transient warming/hyperthermal events superimposed on the long term warming trendfrom Late Paleocene (~56 Ma) to the Early Eocene (~52 Ma) and aremarked by negative Carbon Isotopic (δ13C) Excursions (CIEs) in variousproxy records (Zachos et al., 2010). Short lives (ranging between 50and 200 kyr) of these CIEs/hyperhtermals indicate both rapid additionof 13C depleted carbon to the long-term carbon cycle as well as rapidburial of 13C depleted organic matter (Bowen and Zachos, 2010) duringthese episodes e.g., Paleocene–Eocene Thermal Maximum (PETM) orEarly Eocene Thermal Maxima 1 (ETM1), (ETM2) or H1, H2, I1, and I2(Dickens et al., 1995, 1997). Considered as a past analog of future green-house earth with ongoing rapid addition of 13C depleted carbon from

fossil fuel burning decades of research on these paleo-hyperthermalsmainly focused on understanding both the mechanisms and conse-quences of these events. Characterized by global surface temperaturerise of ~5 to 9 °C (McInerney and Wing, 2011) the PETM was the mostprominent among these hyperthermals. Newly discovered Early EoceneHyperthermal events (EEHs) i.e., H1, H2, I1, and I2 have received lessattention compared to the PETM. One of the most distinctive featuresof the PETM is ~2 to 7‰ negative CIE both in atmosphere–ocean systemdenoting addition of N2000 Gt of 13C depleted carbon to the long-termcarbon cycle (Dickens et al., 1995; Dickens et al., 1997). However, themagnitude of these CIEs varies depending on the carbon phase analyzed,paleo-latitudinal location, and the completeness of the sedimentary re-cord (Bowen et al., 2006; Sluijs et al., 2007; Sluijs and Dickens, 2012).In case of the PETM, magnitude of the negative CIE is typically 2 to 4‰in marine carbonate (benthic and planktic foraminifera; Kennett andStott, 1991; Thomas and Shackleton, 1996)while it is 4 to 5‰ in bulk ter-restrial organic carbon (Domingo et al., 2009), and ~6‰ in soil carbonate(Koch et al., 1992). Similar to the PETM,magnitude of the negative CIE of

Palaeogeography, Palaeoclimatology, Palaeoecology 387 (2013) 91–103

⁎ Corresponding author. Tel.: +91 3222283392.E-mail address: sarkaranindya@hotmail.com (A. Sarkar).

0031-0182/$ – see front matter © 2013 Elsevier B.V. All rights reserved.http://dx.doi.org/10.1016/j.palaeo.2013.07.008

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the ETM2/H1 in marine calcareous microfossils and bulk organic mattervaries from ~1 to 1.5‰ (Stap et al., 2010) and ~3 to 3.5‰ (Sluijs et al.,2009; Clementz et al., 2011) respectively. Themagnitude of the negativeCIE of the H2 and other two hyperthermals (I1 and I2) in high resolutionmarine carbonate varies from 0.2 to 0.7‰ (Stap et al., 2010), ~0.5 to0.7‰, and ~0.2 to 0.6‰ (Nicolo et al., 2007) respectively. However,with addition of new data, obtained from different carbon phases, mag-nitude of these hyperthermals may change in future, as it happened forthe PETM. Since the magnitude of the CIEs is very crucial to quantifythe amount of carbon added to the long-term carbon cycle (Sluijs et al.,2007; Sluijs and Dickens, 2012) and consequent climate changes, thelarge spread in the reported magnitude for the CIEs invited severalconflicting opinions regarding the temperature and precipitation changeacross these CIEs (Zeebe et al., 2009; Diefendorfa et al., 2010). For exam-ple, ocean acidification at the onset of the PETM leads to dissolution ofpreviously deposited marine carbonate while prohibiting deposition ofnew carbonates. Thusmarine carbonate fails to record the real depletionin 13C at the PETM onset which has the largest isotopic shift. Hence, ma-rine carbonate many a times underestimates the magnitude of the neg-ative CIEs (Zachos et al., 2005). Further, decreased pH during oceanacidification reduces the CO3

2− concentration thereby enriching theδ13C of marine fossil carbonates (Spero et al., 1997; Uchikawa andZeebe, 2010). Soil carbonate records, on the other hand, are thought tooverestimate the CIEs influenced either by vegetation change (Smithet al., 2007) or by change in soil respiration rate in an elevated atmo-spheric CO2 and increased precipitation regime (Bowen et al., 2004).Bulk organic matter data are expected either to amplify or dampen thesignal depending on the depositional environment and response of thebiosphere with the warming (Sluijs and Dickens, 2012). While mixingof marine and terrestrial organic matter in marginal marine sectionsand change in water use efficiency (WUE) of the plant in a changed cli-matemay either dampen or amplify the signal, plant community change(gymnosperm to angiosperm) can only amplify the CIEs (Schouten et al.,2007; Smith et al., 2007). The net result may be an offset of the CIEs fromactual CIEs, possibly by 1–2‰ (Bowen et al., 2004; Uchikawa and Zeebe,2010). Since, plant community change (i.e., gymnosperm to angiosperm)could not occur near the equator (Jaramillo, 2002; Jaramillo et al., 2006;Jaramillo et al., 2010), δ13C of bulk organicmatter from the equatorial re-gion could only be influenced by hydrologic cycle over and above the ac-tual CIEs, and can shed light on the change in precipitation regime in thetropics during the CIEs. Here we report the PETM and all early EoceneCIEs from bulk organic matter, hitherto unknown from tropical terrestri-al records (Fig. 1a). This first PETM report from an Indian section also ex-hibits comparatively higher magnitude of the CIEs (PETM: ~5.1‰, H1:2.6‰, H2: ~2‰, I1: 2.1‰, and I2: 2‰) and demands an increased

precipitation regime in the equator during the early Eocene predictedby general circulation models.

Further, we make an attempt to constrain absolute age of the PETMand EEHs by Ar–Ar thermochronology of authigenic glauconitespreserved in these sections. This is important because the absolute agefor the onset of PETM is not very well constrained due to the absenceof a datable material (e.g. ash layer) within the PETM body itself.Using radiometric dates of marine ash layers +19 and −17 withinmagnetochron C24r and orbital tuning of marine sediments the age ofthe PETM CIE onset has recently been estimated as 56.011–56.293 Ma(Westerhold et al., 2009). Jaramillo et al. (2010) dated the PETM(56.09 ± 0.03) from a terrestrial section by U–Pb dating of zirconseparated from a tuff lying in the upper part of the PETM body. The glau-conites dated in the present study occur exactly within the bodies of thePETM and EEHs and hence have added significance to the chronology ofthese hyperthermals.

2. Materials and methods

Sediment samples of the Cambay shale Formation were collectedfrom both Vastan (21° 26.152′N and 73° 06.968′E; Fig. 1b) and Valia(21° 35.837′N and 73° 12.027′E; Fig. 1b). At Vastan, samples weretaken from 60 m thick exposed section of the Vastan mine face as wellas ~100 m drill core raised by the Gujarat Industrial Power CorporationLimited (GIPCL). Later composite litholog was prepared using the~10 m thick upper coal seam (Fig. 2) and Nummulites bearing zoneidentified in both mine face and also in the core. Another ~320 m drillcore penetrating up to the late Cretaceous Deccan Trap basalt was raisedfromValia, at ~20 kmNE of the Vastan. The sampling resolution at Valiais higher (at ~50 cm interval throughout the core) than that of Vastan(50 cm to 1 m). Nannofossils were separated from the Vastan sedi-ments by standard random settling technique, smear-slides preparedand studied with a polarizing microscope. Selected slides were goldsputtered and studied under a Scanning Electron Microscope (SEM) atBirbal Sahni Institute of Palaeobotany, Lucknow. Quantitative estima-tions were made by counting index species per unit area. For pollenanalysis, sediments were treated with a 10% KOH solution to dissolvehumic acid and liberate palynomorphs. Material was sieved through200 μm mesh, filtrate centrifuged, washed and processed by theconventional technique of acetolysis. Palynomorphs were mounted formicroscopic study with 50% glycerin and pollen grains were countedin each sample for quantitative estimation.

For δ13C analysis of bulk organic matter ~1–50 mg de-carbonatedsample was combusted in a Flash Elemental Analyzer. The evolvedCO2, purified through a moisture trap, was measured for its isotopic

Fig. 1. (a) Paleogeographic locations of the study area and other PETM sectionswhere all Eocene hyperthermals have been documented (Supplementary Table 5); note paucity of tropicalhyperthermal sites. 1 = ODP 690; 2 = ODP 1262; 3 = ODP 1263; 4 = ODP 1265; 5 = ODP 1267; 6 = ODP 1051; 7 = DSDP 550; 8 = Lomonosov Ridge; 9 = Possagno section, Italy;10 = Contessa section; 11 = DSDP 577; 12 = Mead Stream, New Zealand; 13 = Dee Stream, New Zealand; 14 = Bighorn Basin,Wyoming, U.S.A. (b) Detailed geological map of Vastanand Valia areas.

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compositions in a Delta Plus XP continuous flow mass spectrometer(analytical precision ± 0.1‰) at the National Stable Isotope Facility,Indian Institute of Technology, Kharagpur. Isotopic results arepresented in δ notation as per mill (‰) deviation from standard. Where,δ = ((Rsample − Rstandard) / Rstandard) × 1000 and R = 13C / 12C. Theratios of total organic carbon to nitrogen (C/N) were also measured. Forthis, samples were converted to N2 and CO2 in the elemental analyzerand the percentage of N and C was calculated from the peak areasobtained from the sum of the m/z 28 and 29, and 44, 45, and 46 respec-tively. Typical analytical error was b1%.

For biomarker analysis, ~1–5 g powdered sediment samples,encompassing all lithological types, were extracted using an acceleratedsolvent extractor (Dionex ASE 350) with dichloromethane (DCM)/methanol (MeOH) 9:1 (v/v) over 3 cycles at 1700 psi and 100 °Cfor 15 min at the Indian Institute of Science Education and Research,Kolkata. Total lipid extract (TLE) was concentrated in a rotary-evaporator to near dryness. The hydrocarbon fraction was elutedusing hexane from the TLE using short columns filled with activated sil-ica gel. Semi-quantitative measurement of n-alkanes was performedusing an Agilent 7890 GC System fitted with a FID detector and Flukan-alkane standard mixture (C10–C40; part no. 68281). Separation wasachieved with a HP-5MS column and with helium as the carrier gas.The GC oven temperature program was as follows: 40 °C (held for2 min) to 320 °C at 8 °C/min, and held at 320 °C for 12 min.

For lignin phenol analysis, powdered sediment samples (~15–300 mg) were weighed into stainless steel reaction vessels with CuOpowder and ferrous ammonium sulfate, and purged under N2 gas for

3 h. The vessels were then filled with 2 M NaOH, placed in a rotatingcarousel, heated to 150 °C and held for 150 min, cooled and ethylvanillin and DL-12 hydroxystearic acid were added as internal recoverystandards (IRS). The high molecular-weight, acid-insoluble organicswere then precipitated by acidification, and soluble lignin-derived phe-nols were extracted. Lignin phenols monomers were trimethylsilane(TMS) derivatized and analyzed in a Shimadzu QP2010 PLUS quadru-pole mass spectrometer interfaced to a gas chromatograph andquantified relative to the IRS. Lignin phenol vegetation index is definedas LPVI = [{S(S + 1) / (V + 1) + 1} × {C(C + 1) / (V + 1) + 1}]Where V, S and C are expressed in % ofλs orΣ8 lignin phenols of vanillyl,syringyl, cinnamyl (mg/100 mg organic carbon; Tareq et al., 2004).

For strontium (Sr) isotope, fossil shell (bivalves and benthic forams)sampleswere ultrasonically cleaned, dried, leached in ultrapure 1 NHCland residue removed. Sr was separated from the leachate by conven-tional cation exchange column chromatography and loaded onto atantalum filament. 87Sr/86Sr was measured in a Thermo Fischer Tritonthermal ionization mass spectrometer at the KDM Institute of Petro-leum Exploration, Dehradun. The measured ratios are normalized to86Sr/88Sr = 0.1194. All sample ratios were adjusted to measured 87Sr/86Sr ratio of NIST 987 standard which was ~0.000015 higher than therecommended value.

Two glauconite samples were dated by the Ar–Ar method at theIITB-DST National Facility for Ar–Ar Geo-thermochronology by theconventional step-heating method following Sen et al. (2012). All agespresented herein are measured against the 523.1 ± 2.6 Ma MMhb-1(Renne et al., 1998). The 95.03 ± 1.11 Ma glauconite standard GL-O

Fig. 2. Graphic correlation of the lithounits at Vastan (top); note westward thickening of the units suggesting basinal depocenter. Composite litholog and a part of the Vastan mine facesection showing the relative positions of lower marine layer, Nummulites burdigalensis (Nb) zone and ETM2/H1 hyperthermal (bottom). Correlation of lithounits of Vastan with that ofthe Valia area, situated NE is also shown.

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(Odin et al., 1982), analyzed along with the samples to check thelaboratory procedures and accuracy of the measurements, yielded anage of 93.5 ± 0.7 Ma. (Supplementary Fig. 1; details are in supplemen-tary materials).

3. Results and discussion

3.1. Depositional environment

Shale-lignite sequence at both Vastan and Valia, belongs to Cambayshale Formation and was directly deposited over the Deccan Trapbasement (Punekar and Saraswati, 2010) in southern Cambay basin.The sequences at both sites consist of alternate lignite and gray shaleencasing thick (meter scale) wedge shaped coquina like marine shellbeds and centimeter to decimeter scale silt/fine sand lenses (Fig. 2). Thepresence of fine grained sediments, anoxic to dysoxic sedimentary facies(e.g., coal/black-/gray-shale;Weaver et al., 2011), lack of tide orwave fea-tures, profuse bioturbations in gray shales and lenticular silt/sand/shellbeds are suggestive of a possible lagoonal environment (Holz, 2003).The Vastan section contains two prominent marine incursion horizons.The lower one is at ~200 m depth yielding rich nannoplankton assem-blage and cosmopolitan Operculodinium cf. centrocarpum dinoflagellatecharacteristic of coastal to near open-ocean environments capable of tol-erating largefluctuations in temperature and salinity (Candel et al., 2009).The upper one occurs at ~170 m depth yielding larger benthic foramini-fers (e.g. Nummulites) and profuse marine bivalves. A terrestrial mammalrich horizon occurs ~10 m above this horizon (Fig. 2). The proximal Valiasection is practically devoid of any marine fossil in its lower part exceptoccurrence of a number of foraminifer-marine mollusk rich beds in

its upper part over a large interval between 40 m and 120 m. Althoughmarine beds occur at certain levels, lignite layers are frequent throughoutthese sections implying a dominant near-terrestrial environment (fordetails see Samanta et al., 2013).

3.2. Chronology

Both marine intervals at Vastan contain diagnostic marine fossils. Inthe lower unit, thermophilic calcareous nannofossil assemblage first ap-pears at a depth of ~215 m reaching maximum abundances between200 m and 190 m and represented by Discoaster araneus (nannoplank-ton zone [NP] 9b to NP10a), Rhomboaster cuspis (NP9b to NP10a;Aubry, 1999), Tribrachiatus bramlettei (NP10 to NP11; Martini, 1971),and Fasciculithus tympaniformis (end of NP4 to NP9b; Fig. 3). Appearanceand blooming of these nannoplanktons are characteristic of the Paleo-cene–Eocene thermal maximum as observed in other type are marinesections (Raffi et al., 2005; Mutterlose et al., 2007). Base of T. bramlettei,D. araneus and R. cuspis typically coincides with the PETM whileF. tympaniformis terminates at the PETM. This unique association ofT. bramlettei, D. araneus, R. cuspis, and F. tympaniformis is globallyassigned as the PETM (Raffi et al., 2005). However, continuous bio-zonation was not possible in this near terrestrial setting and hence theexact level of blooming and First Appearance Datum (FAD) is not identi-fiable. The nannoplankton association only suggests the possibility of theexistence of the PETMbetween ~215 mand 190 m at this location. Larg-er benthic foraminifera Nummulites burdigalensis burdigalensis andNummulites burdigalensis kuepperi occur in the upper marine horizon(160 m–170 m, Punekar and Saraswati, 2010) corresponding to earlyShallow Benthic Zone (SBZ) 10. Based on the latest magnetostratigraphy

Fig. 3. Typical nannofossil biostratigraphic ranges across the PETM and light microscopic (1–5) and SEM (6–7) photographs of their occurrences in Vastan at ~200 m depth. (1)Fasciculithus tympaniformis (Hay andMohler in Hay et al., 1967), (2) Tribrachiatus bramletti (Proto Decima et al., 1975), (3) Discoaster araneus (Bukry, 1971), (4,5,6,7) Rhomboaster cuspis,(Bramlette and Sullivan, 1961).

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of Gradstein et al. (2004) and re-calibration of the SBZ-10 by Mochaleset al. (2012) the time span of SBZ-10 has recently been revised to51.5 Ma to 53.5 Ma (see later discussion).

To substantiate the above biostratigraphic ages we also analyzed87Sr/86Sr ratio of marine bivalves from lower fossiliferous interval ofVastan, which have excellently preserved pristine aragonitic shells(Supplementary Fig. 2). The Sr ratio of these shells varies from0.707752 ± 0.000009 to 0.707722 ± 0.000005. These ratios are verysimilar to those earlier published by Clementz et al. (2011) at Vastan.Using the strontium isotope stratigraphic calibration of McArthur et al.(2001), the numerical best fit ages of these bivalves (red dots, Fig. 4)suggest an age range between ~56.5 Ma and 54.5 Ma (SupplementaryTable 1). Considering the new and published 87Sr/86Sr data along withthe biostratigraphic ages it can be inferred that the age of the lowerpart of Vastan sequence (below ~190 m depth) ranges from ~56.5 Mato at least 54.5 Ma. 87Sr/86Sr ratios (Supplementary Table 2) of largerbenthic foraminifers from the upper (~115 m to 50 m depth) fossilifer-ous beds of the Valia (blue dots, Fig. 4) suggest a span of sedimentationbetween 33 and 38 Ma. This suggests that in Valia the sediment depos-ited below ~115 m must be older than 33 Ma.

Absolute age for the PETM is, so far, not available due to the absenceof datable ash layer within the PETM body itself. Earlier works mostlyrelied on the cyclostratigraphy (orbital chronology) based relative ageof the PETM from well dated ash layers (e.g. ash +19 and−17) fallingwithin magnetochron C24r (see Westerhold et al., 2009 for details).However, complications arose due to (1) the presence of a debatable405 kyr eccentricity cycle during the Early Paleogene, (2) the chaoticdiffusion in the orbital solutions beyond ~42 Ma (Laskar et al., 2004),and (3) absolute age of the ash −17. Although, astronomicallyrecalibrated age of the Fish Canyon Tuff (FCT) standard (28.201 Ma,Kuiper et al., 2008) from its standard monitor age (28.02 Ma, Renneet al., 1998; Villeneuve, 2004) and new orbital solutions partially solvethe issue, but these came up with three alternative ages for the PETM(see Westerhold et al., 2009 for details). Jaramillo et al. (2010) firstdated the PETM (56.09 ± 0.03) from a terrestrial section by U–Pb dat-ing of zircon separated from a tuff lying in the upper part of the PETMbody. Considering the above discrepancies we separated authigenicglauconite from the lower marine interval at Vastan (Fig. 2, position ofglauconite in the litholog) and dated them by 40Ar/39Ar method. Theglauconite sample from 217.5 m depth at Vastan gives an age 56.6 ±0.7 Mawhich agrees excellently with the PETMage provided by the op-tion 3 of Westerhold et al. (2009) and Jaramillo et al. (2010; Fig. 5). In-cidentally the characteristic PETM nannofossil assemblage of T.bramlettei, D. araneus, R. cuspis, and F. tympaniformis is also found justabove this glauconite layer. Glauconite sample from the top part of

Valia core gives an age of 52.6 ± 1.0 Ma for 192.5 m depth. This dateis closer to the astronomically calibrated age of I1/I2 hyperthermal(~52.7 Ma; Zachos et al., 2010; see a detailed discussion below) ob-served in marine record. All the above bio-, Sr- and Ar–Ar-chronologiesof Vastan and Valia strongly indicate possibilities of preservation of thePETM and EEHs climatic signals in these sediments and are further sup-ported by their corresponding δ13C chemostratigraphy as shown below.

3.3. Diagenesis and fingerprinting sources of organic matter by δ13C, C/N,and biomarker

Caution must be taken when dealing with the δ13C values of bulkorganicmatter as carbon isotope signalmay be altered by (a) burial dia-genesis of organic matter (OM) and (b)mixing of sources i.e., terrestrialandmarine OM (Carvajal-Ortiz et al., 2009). Thus, before using bulk OMisotopic composition for paleoclimate study, it is necessary to addressthe diagenetic history of these sediments.

All the marine bivalve shells recovered from the mine and coresection show exceptionally well preserved original aragonitic shellswith the outermost organic layer (periostracum) intact. A deep burialdiagenesis would have transformed the aragonites to micritic calciteor re-precipitated crystalline sparite. Further, these bivalves preservepristine Paleocene–Early Eocene marine 87Sr/86Sr rations (Clementzet al., 2011; see discussion on chronology). Rock-Eval Pyrolysis oflignites from the upper coal seam at Vastan shows Tmax values rangingbetween 400 and 423 °C suggesting their immature nature (Petersand Cassa, 1994; Dutta et al., 2012). This is also corroborated by thepresence of characteristic angiosperm biomarkers within these sedi-ments (Dutta et al., 2011, 2012).

To evaluate the OM degradation and microbial contributions to OMand their effect on δ13C we also carried out biomarker analysis for

Fig. 4. Chronology of Vastan and Valia sediments based on strontium isotope ratios (87Sr/86Sr) of marine bivalves (red dots) and foraminifers (blue dots) respectively followingMcArthur et al. (2001). (For interpretation of the references to color in this figure legend,the reader is referred to the web version of this article.).

Fig. 5. Comparison of astronomical and radioisotopic ages for the Paleocene-Eocene ther-mal maximum (PETM). Dark blue bars mark the absolute age ranges for the onset of thePETM based on the age and relative distance of ash −17 with respect to the age of theFish Canyon Tuff (FCT) standard of 28.02 (Renne et al., 1998), 28.201 (Kuiper et al.,2008), 28.305 (Renne et al., 2010), 27.93 (Channell et al., 2010), and 27.89 Ma(Westerhold et al., 2012). Horizontal black lines mark the three possible options of theage ranges for the onset of the PETM based on the astronomically calibrated Paleocenetime scale (Westerhold et al., 2008). The light blue bar marks the new astronomically cal-ibrated absolute age for the onset of the PETM established in Westerhold et al. (2012) byanchoring the geological data to the La2011 (Laskar et al., 2011) eccentricity solution andgreen bar marks the U–Pb dating of onset of the PETM. The red bar denotes the rangebased on Ar–Ar dates of glauconites within the PETM body of Vastan. (For interpretationof the references to color in this figure legend, the reader is referred to the web versionof this article.).

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selective samples (n = 9; Supplementary Table 3). n-Alkane distribu-tion of the samples shows contrasting nature. While few samples arecharacterized by higher proportion of long chain n-alkane (LCNA; C25–C33), the rest shows dominance in the short chain n-alkane (SCNA;C15–C21). The LCNA/SCNA ratio varies between ~12 (n = 4; N1) and0.2 (n = 5; b1). However, irrespective of the LCNA/SCNA ratio, LCNA al-ways shows clear dominance of odd over even n-alkane (odd over evenpreference; OEP) with average chain length (ACL25–33) varying between30.53 and28.68. The carbon preference index (CPI) for the LCNA, varyingbetween 3.25 and 1.25, also suggests clear OEP. Contrasting to the distri-bution of LCNA, SCNA always shows lower (b1) CPI varying between0.77 and 0.38 suggesting even over odd (EOP) preference. n-Alkane de-rived from the terrestrial vascular plants is dominated by LCNA withcharacteristic strong OEP (Eglinton and Hamilton, 1967; Pearson andEglington, 2000). SCNA, on the other hand, is produced by freshwaterphotosynthetic algae and/or macrophytes (submerged/floating plants)and other micro-organisms (Grimalt and Albaiges, 1987; Muri et al.,2004; Van Dongen et al., 2006; Jansen et al., 2008) and shows character-istic EOP. High concentration of SCNAmay also be produced bymicrobialdegradation of primary OM and thus restrict the use of bulk δ13C for anypaleo-environmental analysis (Bergen and Poole, 2002; Carvajal-Ortizet al., 2009). Recent compound specific carbon isotopic analysis ofSCNA from modern soil, however suggested that soil organic mattermay show higher concentration of SCNA with strong EOP primarily de-rived from plant (Kuhn et al., 2010). This study further showed thatthe δ13C values of the SCNAs derived from soil are very similar to theδ13C values of LCNAs from the thriving plant. In the absence of a detailedcompound specific isotope analysis of individual n-alkanes it is difficultto pinpoint the source of SCNA at this stage. Nevertheless OEP in LCNAand its high CPI (N1), and EOP in SCNA, do suggest excellent preservationof original OM and minimal diagenesis/degradation.

Usually lagoon or estuarine sediments receive both autochthonous(in-situ plants) and allochthonous (transported either by tidal invasionof oceanwater or river) organicmatters (Sarkar et al., 2009). Dependingon the source of carbon used for photosynthetic mechanism, terrestrialor aquatic plants, algae, and marine particulate organic matters (POM)acquire different δ13C values. δ13C of two major groups of modern ter-restrial plant i.e., C3 and C4 plants has average values of ~−26 ± 3‰and ~−13 ± 4‰ respectively (Meyers, 1994) for their different photo-synthetic pathways. While the modern freshwater algae (−26‰ to−30‰) are considerably negative than the marine algae (−16‰ to−23‰), marine POM have δ13C ranges (−21‰ to −18‰;Middelburg and Nieuwenhuize, 1998) closer to C4 plants. These valuesprobably were significantly different during the early Paleogene. Hayeset al. (1999) showed that marine organic matter (MOM) of Paleocene–Eocene times (between −26 and −28‰) was depleted than thepresent (−20‰). Apart from δ13C, C/N ratio of organicmatter is anotherpotential tracer for source identification (viz. C3 ≥ 12; Tyson, 1995 andC4 ≥ 20; Meyers, 1994) although overlapping C/N ratios are alsoobserved between plant communities. In comparison the C/N ratio ofmarine OM is distinctly different having a value of ~10. Hence, a combi-nation of both δ13C and C/N (Supplementary Table 4) canfingerprint thesources of organic matter in a lagoonal environment. The ranges of δ13Cand C/N ratios of bulk organicmatter of the Vastan sequence are plottedin Fig. 6a, alongwith large C3 plants (including tropical mangroves), la-custrine and marine algae, and marine POM (phytoplankton) from Bayof Bengal (Sarkar et al., 2009). The C/N ratio at Vastan, varies from 20 to90 (mean ~ 36), indicating dominant input of terrestrial organic matterin this lagoon, where highest C/N ratios correspond to thicker ligniteseams (see Fig. 7 for vertical variation in C/N ratio). The ranges of C/Nratio and δ13C values clearly indicate the presence of C3 typeplant community during this time and are also supported by pollenand lignin biomarker δ13C data of Vastan organic matters (see later dis-cussion). Our data suggest that even in marine intervals contribution ofland plants derived organic matter far exceeded that of marine POMand algae.

Further, the frequency distribution of δ13C in different lithofaciesshows near-normal distributions with similar median values in coal,carbonaceous shale, fossiliferous and gray shale (Fig. 6b). Total OrganicCarbon (TOC) vs. δ13C plot (Fig. 6c) also supports previous observationand suggests no lithology or OM amount dependent bias on δ13C(Fig. 7). More specifically, the undoubted marine incursion horizons,i.e., gray shale with fossils do not show any positive bias towardslower values both for δ13C and C/N (varies between ~20 and 60).Using a simple mass balance model we estimate N85% terrestrial OMcontribution in these lagoons. Such inference, however, may be biasedif selective preservation of OM occurs during early decompositionthereby obliterating the effect of source mixing. This is because lowerC/N values (~6–9) ofmarine POM aremainly an effect of higher amountof proteins (Biggs et al., 1983; Meyers, 1994). Since protein degradesfaster than the other compounds during early degradation, C/N ratioof the POM tends to be higher. Degradation experiment by incubatedmicrobes (Lehmann et al., 2002) showed that C/N ratio of marinePOM can increase from ~6 to merely 10. In contrast, terrestrial plantsenriched in cellulose and containing few nitrogenous compounds,have much higher C/N ratio (Sampei andMatsumoto, 2001). Thus, pos-sibility of lower C/N ratio than original exists during early degradationof terrestrial OM (Meyers et al., 1995). Further, as decomposition pro-gresses, organic carbon can be preferentially removed from terrestrialsediments and inorganic nitrogen increases relative to organic nitrogen(Meyers and Lallier-Vergès, 1999; Sampei and Matsumoto, 2001). Thistoo can reduce the original C/N ratio of the terrestrial organic matter(TOM). It is therefore possible that ~85% terrestrial contribution basedon observed C/N (≥20) ratio may be somewhat underestimated andthe actual terrestrial contribution was even higher.

The above inference is also supported by biomarker data of these OM.Since the samples show considerable concentration of SCNA weemployed a two end ember mixing model following Sikes et al. (2009)to evaluate the marine contribution. For a marginal marine system theproxy Pmar–aq is defined as [C23 + C25] / [C23 + C25 + C29 + C31]where low values (0.01–0.25) indicate terrestrial inputs while highvalues (N0.6) indicate aquatic plants and marine macrophytes. Interme-diate Pmar–aq values (~0.4–0.6) indicate contribution from emergentaquatic plants including mangroves. Pmar–aq values averaging at 0.23 inthe studied samples suggest dominant contribution of terrestrial OMinto the system with minor contribution from emergent aquatic plantsand mangroves in only one sample (0.39). None of the samples showPmar–aq N0.6 suggesting insignificant contribution from marine macro-phyte. Further, considering the depleted δ13C values of the marineprimary producers compared to terrestrial vascular plant during the Pa-leocene (see above; Hayes et al., 1999), the mixing would have depletedthe bulk OM values depending on the marine–terrestrial ratio. No suchtrend, however, is found when δ13C is plotted against marine–aqueousmixing indicator (Pmar–aq; Fig. 6d). Even if we consider that SCNA has amarine source, OEP in LCNA and LCNA/SCNA N1 in several samples clear-ly suggest that the OMwere primarily derived from the terrestrial plants(Carvajal-Ortiz et al., 2009).

3.4. δ13C stratigraphy

Fig. 8 shows the bulk organic matter δ13C stratigraphy at Valia (a)and Vastan (d). The solid line in Fig. 8a represents five pointmoving av-erage through the bulk OM δ13C data of Valia. Due to its lower samplingresolution, the Vastan δ13C data have been plotted as it is in Fig. 8d. Alsoplotted in the Fig. 8b is the global marine carbonate δ13C stratigraphycompiled by Zachos et al. (2008). Five δ13C minima zones are seen atValia section. Two most pronounced minima occur at depths of~270 m and ~245–226 m (below ground level), while the other threeof relatively lesser magnitude occur between ~220 m and 190 mdepth. δ13C values from 190 m upward show monotonous increasethat stabilizes in the rest of the section. The δ13C profile of lagoonalValia section has excellent similarity with that of the marine record.

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The magnitudes (base to peak difference in δ13C of the excursion) ofthese five minima or negative CIEs are 5.1‰ (at 270 m depth), 3‰ (at241 m depth), 1.7‰ (at 212.5 m depth), 2.7‰ (at 205 m depth), and1.7‰ (at 191.6 m depth) respectively. The authigenic glauconites at192.5 m depth in Valia occur just below the last CIE and provided an40Ar–39Ar date of ~52.6 ± 1 Ma. The last CIE i.e. I2 in global marinerecord has been dated at ~52.7 Ma and is ~0.1 Ma younger than thepreceding CIE I1. Given the error of 40Ar–39Ar date we are at the mo-ment unable to resolve this age difference between I1 and I2. Our datanevertheless strongly indicate that the four CIEs between 241 m and191.6 m depth at Valia correspond to the EEHs (ETM-2, H2, I1 and I2)correlatable with those in marine records. The shape, size and magni-tude of the lowermost and largest CIE suggest it to be PETM.

At Vastan also five distinct short lived negative CIEs are observed up-ward from the base of the section. The first major negative CIE occursbetween 231.85 m and 194 m depth with magnitude of 5.2‰ and theother four negative CIEs occur at 152.5 m (2.2‰), 140.7 m (2.2‰),134.5 m (1.6‰), and 117 m (2.3‰) depths. Using the Sr isotope ratiosand partial δ13C profile, the peak near 152 m in the Vastanmine sectionhas already been identified by Clementz et al. (2011) as ETM2 (greenCIE in Fig. 7). Based on the presence of characteristic nannofossil assem-blage, Ar/Ar dating of glauconite (~56.6 ± 0.7 Ma at 217.5 m depth),and 87Sr/86Sr ratio (as discussed earlier; Figs. 7 and 8), we interpretthe lowermost and largest plateau like negative CIE at Vastan (5.2‰)as the PETM (Samanta et al., 2013). Up in the section, the second excur-sion of 2.2‰ is foundwithin the thickest lignite seam andwe assign thisexcursion as the H1/ETM2 (~53.7 Ma; Zachos et al., 2010; Clementzet al., 2011) on the basis of the occurrence of larger benthic foraminiferaN. burdigalensis burdigalensis and N. burdigalensis kuepperi (correspond-ing to early SBZ 10, equivalent to NP 11, see above; Gradstein et al.,

2004; Punekar and Saraswati, 2010; Mochales et al., 2012; Samantaet al., 2013; Figs. 7, 8) at ~10 mbelow.We correlate the three CIEs, over-lying the ETM2, to theH2, I1, and I2 (Figs. 7, 8; Zachos et al., 2010) basedon the shape, amplitude, and approximate timing. At both Vastan andValia the ETM2/H1 is present within the same thick lignite seam. Iden-tification of the PETMand other EEHs at spatially two different locationsin the same basin provides evidence of the early Cenozoic carbon cycleperturbations even in tropical terrestrial realm.

Because all the EEHs are not visible in the global compilation ofZachos et al. (2008) and are reported from only few marine sections,we also plotted in Fig. 8 the carbonate δ13C profile at ODP site 1051 inthe southern ocean that records best the EEHs. The dotted lines inFig. 8 denote the correlation of the PETM and EEHs with the marine re-cords. The CIEs in deep sea carbonates are severely attenuated by disso-lution effect due to ocean acidification (Nicolo et al., 2007; Smith et al.,2007), thus questioning the amplitude of these events and their globalnature. The present study, for the first time, documents all fivehyperthermal/CIE events, including the PETM, in a near-terrestrialequatorial sequence with magnitude of the CIEs larger than or equalto those recorded elsewhere (Supplementary Table 5) and suggeststhese to be global in nature. Specially to be noted that apart from thePETM magnitudes of other hyperthermals viz. I1 (ETM-2), I2, H1 andH2 are also higher at Vastan/Valia compared to other deep or shallowmarine locations. Fig. 7 shows the correlation of the Vastan δ13C profilewith two published terrestrial sections from Claret, Spain and Honey-combs, North America (Domingo et al, 2009). The PETM interval at allthese three terrestrial sections is similar and much expanded (~30–40 m) compared to themarine PETM. An additional CIE is observed im-mediately after the PETM at ~190 m in Vastan and at ~260.3 m in Valia.Such an excursion has also been observed in Claret and Honeycombs

Fig. 6. (a) Cross plot of δ13C andC/N ratios of bulk organicmatter fromVastan; for comparison total ranges of C3plants,marine and lacustrine algae and tropicalmarine organicmatter fromBay of Bengal (Sarkar et al., 2009) are also shown. Note the Vastan data fall in range of terrestrial C3 plants. (b) Frequency distribution of δ13C of Vastan bulk organic matter in variouslithologies; note the δ13C values have no lithological bias. (c) Cross plot of TOC and δ13C of bulk OM showing absence of any correlation. (d) Cross plot of δ13C of bulk OM and Pmar–aq.

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sections (Fig. 7), although its significance is not fully understood. Belowwe discuss the implications of the large CIEs in this tropical terrestrialenvironment.

3.5. Magnitude of CIE, plant community and climate across Indian PETM

The magnitudes of the PETM CIE at Vastan and Valia are 5.2‰ and5.1‰ respectively, which are similar to most terrestrial sections(Domingo et al., 2009) but ~0.7‰ to 0.6‰ larger than the maximumrecorded marine and estimated global atmospheric CIE (~4.5‰,Handley et al., 2008; Diefendorfa et al., 2010). Based on biomarker iso-tope studies, the amplified terrestrial signal has previously beenexplained by a change in plant community (conifer to angiosperm)across the PETM, where the angiosperms exhibit ~2–6‰ higher CIEcompared to conifers due to the difference in their water use efficiency(WUE, Schouten et al., 2007; Smith et al., 2007). These records, howev-er, come from the high latitude regions (Schouten et al., 2007; Smithet al., 2007) conducive for conifer habitat. The presence of conifers orits shift to angiosperm taxa in the vegetation is unlikely for equatoriallagoons like Vastan and Valia. To test this we carried out palynologicalanalysis across the Vastan and Valia PETM. The detailed time stratigra-phy of pollen abundance is underway and will be reported elsewhere.The entire Vastan sequence exhibits abundant terrestrial elements be-longing to the families Araceae, Arecaceae, Annonaceae Bombacaceae,Cytheaceae, Dipterocarpaceae, Liliaceae, Meliaceae and Sapotaceae(Fig. 9). These typical rain forest taxa dominate Valia and Vastan sec-tions both at PETM and post-PETM levels and do not show any high lat-itude/altitude gymnospermous elements at all. This suggests that thechange in plant community (e.g. conifer to angiosperm) did not playany important role for the large Vastan–Valia CIE.

Another factor that can potentially influence the carbon isotope frac-tionation in terrestrial plants is rainfall. A global compilation of δ13Cvalues of all C3 plants shows an inverse relationship between δ13C andmean annual precipitation (MAP). A recent in-situ Dipterocarpaceae

(e.g. Albertopollenites; Fig. 9) tree ring experiment in a tropical forestin Thailand also shows similar relationship, where 13C depletion wasobserved during higher rainfall as a consequence of higher stomatalconductance and decreased WUE (Ohashi et al., 2009). As shownabove, the tree elements in Vastan and Valia belong to Araceae,Arecaceae, Annonaceae, Bombacaceae, Cytheaceae, Dipterocarpaceae,Liliaceae, Meliaceae and Sapotaceae families all of which are wet-loving (Jaramillo et al., 2010). In particular, Dipterocarpaceae is a wellknown family of trees of tropical Asian rain forests covering as muchas ~30% of the modern forest covers. Several of these plants today are,however, confined to the very wet climatic zone of western Ghatswhere MAP is exceptionally high between 2500 and 5000 mm,representing a tropical evergreen forest (Prasad et al., 2009). Recentstudy of terpenoid chemistry of resins from ETM2 level of Vastan lignitebeds also indicated dominance of Dipterocarpaceae plants in Early Eo-cene time, much older than their previously known global appearanceat Oligocene time (Dutta et al., 2011). Our pollen study indicates thatthey could possibly be older, originating even during the PETM. The em-pirical relationship between δ13C of modern organic matter (Kohn,2010, see above) and MAP suggests that an increased precipitation of~400–600 mm across the PETM interval might explain the excess mag-nitude of ~0.7‰ to 0.6‰.

Several lines of evidences indeed suggest a possible increase in rain-fall amount at this location. For example, the sedimentation rate inVastan looks fairly high. Orbital chronology suggests that duration ofthe PETM interval is only ~170 kyr and considering its expandedPETM interval at Vastan (~35 m) it implies an increased continentalerosion and sediment accumulation rate probably due to a very hightropical rainfall regime in an ambient high CO2 climate. At Valia thePETM interval is ~10 m thick but occurs within a coal seam. The lesserthickness is probably due to very high compaction of coal seams com-pared to the PETM interval of gray shale at Vastan. To substantiatethis, we carried out analyses of various lignin phenol compounds viz.Vanillyl, Syringyl and Cinnamyl at several levels of the Vastan sequence.

Fig. 7.Bulk organicmatter δ13C stratigraphy andnannofossil across the PETMat theVastanmine and correlation of CIEs (hyperthermal events). For comparison the δ13C stratigraphy acrossthe terrestrial PETM sections of Claret (Spain), and Honeycombs (North America) and previously reported ETM2/H1 CIE at Vastan (green CIE) are also shown. C/N ratio of bulk organicmatter, TOC (%), and abundance of lignin phenol at Vastan are shown. Note high C/N ratios (≥30) throughout the section suggesting terrestrial sources, highest values correspondingto thickest lignite seams. b1000 LPVI value (vertical yellow line) denotes woody angiosperm tissue preservation in coaly beds. High 3,5Bd at Vastan is suggestive of high soil erosion(for details see text). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.).

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Fig. 8. Lithologs alongwith bulk organic matter δ13C stratigraphy of Valia (five point moving average) and Vastan. The δ13C stratigraphy is compared and correlatedwith a general global carbon isotope (carbonate) record based on the data compiledfrommore than 40 DSDP and ODP sites (Zachos et al., 2008) and carbonate δ13C stratigraphy of ODP 1051 of Southern Ocean best recording the EEHs (Cramer et al., 2003). Both the Indian sections show amplifiedmagnitudes compared to themarinerecords with both PETM and EEHs clearly discernible.

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The lignin phenol vegetation index (LPVI) is a useful parameter todifferentiate woody and non-woody angiosperm tissues in terrestrialorganic matter. Certain levels of the lower part of the sequence yieldLPVI value N1000, suggesting preservation of non-woody angiospermtissues (Tareq et al., 2004), which decreases up-section (Fig. 7; Supple-mentary Table 6). This is consistent with thicker coal seams up in thesection, where more woody material was preserved possibly due tohigher burial of terrestrial plant matters compared to the lower part ofthe sequence characterized by much thinner seams. We further ana-lyzed a specific compound 3,5-dihydroxybenzoic acid (3,5Bd) phenolthat is thought to be a product of lignin degradation in soils (Ugoliniet al., 1981) and thus an effective tracer for soil erosion in sediments(Dickens et al., 2007). The (3,5Bd) phenol as well as 3,5Bd to totalVanillyl (3,5Bd/V) ratio inmost of the section shows high concentrationreaching maximum up to ~1.1 mg/100 mg of total organic carbon(Fig. 7; Supplementary Table 6). Concentration of this phenol is lowonly in the calcareous nannofossil rich, palynologically barren andlower C/N ratio marine Vastan PETM interval at ~200 m. Overall high3,5Bd throughout the Vastan section suggests increased soil erosionand overwhelming supply of terrestrial organic matter possibly due tointense tropical precipitation.

Application of lignin phenols in paleo-records specially in deep timeis, however, rare and no attempt has so far beenmade where change in3,5Bd has been directly compared with precipitation indicator like δDof n-alkane. Since 3,5Bd is a lignin degradation product in oxic soilenvironment and soil erosion is positively correlated with rainfallamount, its concentration in sediments is thought to be positivelycorrelated with rainfall amount through soil erosion (Dickens et al.,2007). We infer that the large PETM CIE and high 3,5Bd in Indian

sections are essentially products of increased MAP and consequent soilerosion.

One might, however argue that the CIE signal is an effect of modifi-cation by mixing of MOM and TOM in these marginal marine sections.As mentioned Hayes et al. (1999) showed that MOM of Paleocene–Eocene times (between −26 and −28‰) was depleted than thepresent (−20‰). The difference probablywasdue to increased 13C frac-tionation by the carboxylation enzyme Rubisco caused by high pCO2 inpast ocean water (Freeman and Hayes, 1992). TOM on the other hand,had relatively higher values around −24‰ during Paleocene–Eocene.Considering these end members for the early Cenozoic, a marine incur-sion in any marginal terrestrial environment might show amplificationof the CIE in the bulk OM δ13C at the onset of PETM. Sedimentary recordsfrom several passive continentalmargins exhibit that global average sealevel rose during the PETM (Sluijs et al., 2008a). Eventually higher sealevel increased supply of depleted MOM (−26 to −28‰) to themarginal marine sections. But in case of Vastan all tracers viz. LPVI,C/N and 3,5 dihydroxy benzoic acid suggest that supply of TOM to thismarginal marine section increased during Late Paleocene to EarlyEocene and supported by evidences of higher river discharge to theshelves in many locations (Crouch et al., 2003; Hollis et al., 2005;Giusberti et al., 2007; Sluijs et al., 2008b) andhigher rainfall/MAPduringthis interval. These two processes have different effects e.g., higheramount of MOM causes amplification of CIE, whereas higher amountof TOM would dampen it. We demonstrated earlier that these coal ba-sins probably received ≥85% TOM. Hence the observed high PETM CIEis in spite of this damping effect of TOM, if any, and is probably a precip-itation effect. To test occurrence of higher precipitation we analyzedclaymineralogy of the shales in this basin. Akin to several other tropical

Fig. 9. Some representative palynotaxa across the Vastan and Valia PETM and Early Eocene. All the taxa belong to wet-loving families like Annonaceae, Arecaceae, Araceae, Bombacaceae,Dipterocarpaceae and Liliaceae of tropical rain forest community.

100 A. Samanta et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 387 (2013) 91–103

PETM sections, the presence of monomineralic kaolinitic clays in all theshale layers in this basin (Supplementary Fig. 3) indicates severe flush-ing of weathered profiles in a continuous wet climate (Robert andKennett, 1994; Thiry, 2000; Clechenko et al., 2007; Schmitz andPujalte, 2007). Elsewhere high moisture delivery was indicated by de-pleted n-alkane D/H values in the Arctic Ocean (Pagani et al., 2006)and Neotropics of South America (Jaramillo et al., 2010). AdmittedlyD/H values in alkanes in these Indian sections can only give the final an-swer. Nevertheless, taking all the geochemical and mineralogical datainto account, Vastan/Valia data strongly supports the predictions ofcoupled ocean–atmosphere model or general circulation model (GCM)of higher precipitation in tropics too during awarmer earth. The precip-itation increase possibly resulted due to the more availability of watervapor, larger water holding capacity of the atmospheric reservoir,expansion of Hadley cell and intensified vapor transport (Douvilleet al., 2002; Retallack, 2008; Zhou et al., 2011).

4. Conclusions

High resolution carbon isotope (δ13C) stratigraphy, calcareousnannofossils, biomarker and pollen assemblages of lagoonal lignitebeds of the Cambay shale, western India have been studied. Datashow complete preservation of all the Early Eocene CIE events (viz.H1/ETM2/ELMO, H2, I1, and I2) including the PETM, hitherto unknownfrom tropical terrestrial records. Relatively largermagnitudes of the CIEsfor all the hyperthermals indicate strengthening of hydrological cycleduring the PETM and all the Early Eocene hyperthermal/CIE events. Var-ious proxy data spanning the entire time period ~56–52 Ma also sug-gest that higher organic burial and soil erosion favored deposition ofthick lignitic seams as a consequence of high tropical precipitation.The presence of an intense hydrological cycle is also evident by the per-sistence of the tropical rain forest elements across the PETM consistentwith the GCM prediction for greenhouse earth.

Acknowledgments

This work forms part of the Ph.D. thesis of A. Samanta, who thanksIIT, Kharagpur, for a fellowship. A. Sarkar thanks the Department ofScience and Technology (DST), NewDelhi for funding a research projecton Paleogene sediments of western and northwestern India underwhich the present work was carried out. Bulk isotope and lignin phenoldata were generated in the mass spectrometer laboratory of IIT,Kharagpur funded by the DST and organic geochemistry laboratory,Purdue University respectively. JR and RG thank the Director, BirbalSahni Institute of Palaeobotany for necessary help. KP thanks DST,New Delhi for funding the Ar–Ar mass spectrometer national facility(Grant No. IR/S4/ESF-04/2003). We thank Gujarat Industrial PowerCorporation Limited (GIPCL) for giving permission to carry out thefield work at Vastan mine area and for kindly providing the drill coresamples. SSR thanks the Executive Director, KDMIPE for giving permis-sion for Sr isotope analysis and collaboration. We thank Greg Retallackand two other anonymous reviewers for critical comments whichgreatly improved the manuscript.

Appendix A. Supplementary data

Supplementary data to this article can be found online at http://dx.doi.org/10.1016/j.palaeo.2013.07.008.

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Late Paleocene–early Eocene carbon isotope stratigraphyfrom a near-terrestrial tropical section and antiquity

of Indian mammals

A Samanta1,∗, A Sarkar

1, M K Bera1, Jyotsana Rai

3 and S S Rathore2

1Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur 721 302, India.2KDM Institute of Petroleum Exploration, Dehradun 248 195, India.

3Birbal Sahni Institute of Palaeobotany, Lucknow 226 007, India.∗Corresponding author. e-mail: arpitas25@gmail.com

Late Paleocene to early Eocene (∼56 to 51 Ma) interval is characterized by five distinct transient warm-ing (hyperthermal) events (Paleocene–Eocene thermal maximum (PETM), H1/ETM2/ELMO, H2, I1and I2) in a super greenhouse globe associated with negative carbon isotope excursions (CIEs). Althoughwell-documented marine records exist at different latitudes, terrestrial PETM sections are rare. In par-ticular, almost no terrestrial records of either the PETM or early Eocene hyperthermals (EEHs) are yetavailable from the tropics. Further, evolution of modern order of mammals near the PETM has beenrecorded in many northern continents; however, the response of mammals in the tropics to these warm-ing events is unknown. A tropical terrestrial record of these hyperthermal/CIE events, encompassingthe earliest modern order mammal bearing horizon from India, can therefore be vital in understandingclimatic and biotic evolution during the earliest Cenozoic time. Here, for the first time, we report highresolution carbon isotope (δ13C) stratigraphy, nannofossil, and Sr isotope ratio of marine fossil carbon-ate from the Cambay Shale Formation of Western India. The record shows complete preservation of allthe above CIE events, including the PETM, hitherto unknown from the equatorial terrestrial records.δ13C chemostratigraphy further suggests that at least the present early Eocene mammal-bearing hori-zon, recently discovered at Vastan, does not support the ‘out of India’ hypothesis of earliest appearanceof modern mammals and subsequent dispersal to the Holarctic continents.

1. Introduction

The transition from late Paleocene to early Eocene(∼56 to 51 Ma) witnessed a series of short-livedhyperthermal events (Paleocene–Eocene thermalmaximum (PETM), H1/ETM2/ELMO, H2, I1,and I2), superimposed on the long-term globalwarming trend (Cramer et al. 2003; Nicolo et al.2007; Zachos et al. 2010). Each hyperthermal

event, lasting between 50 and 200 Kyr, is markedby characteristic negative carbon isotope excur-sions (CIEs), signifying rapid addition of 13C-depleted carbon to the exogenic carbon cycle(Lourens et al. 2005; Zachos et al. 2010). Amongthe CIEs, only the PETM (∼55.5 Ma) is glob-ally well-recognized, while the other early Eocenehyperthermals (EEHs) have been recorded mostlyfrom few high-latitude deep ocean sites (figure 1a).

Keywords. Tropical terrestrial Paleocene–Eocene thermal maximum (PETM); early Eocene hyperthermals; carbon isotope

excursion; modern order mammal.

J. Earth Syst. Sci. 122, No. 1, February 2013, pp. 163–171c© Indian Academy of Sciences 163

164 A Samanta et al.

Figure 1. (a) Paleogeographic locations of Vastan and other PETM sections where all Eocene hyperthermals have beendocumented; note paucity of tropical hyperthermal sites. 1 = ODP 690; 2 = ODP 1262; 3 = ODP 1263; 4 = ODP 1265;5 = ODP 1267; 6 = ODP 1051; 7 = DSDP 550; 8 = Lomonosov Ridge; 9 = Possagno section, Italy; 10 = Contessa section;11 = DSDP 577; 12 = Mead Stream, New Zealand, 13 = Dee Stream, New Zealand. (b) Detailed geological map of Vastanarea.

Equatorial or shallow marine records of theseEEHs are rare, viz., only at DSDP/ODP sites 577,1215, and off-New Zealand coast. Almost com-pletely absent are the tropical terrestrial recordsof either the PETM or EEHs (Nicolo et al. 2007;Leon-Rodriguez and Dickens 2010). While thePETM has been reported from terrestrial sec-tions of Colombia and Venezuela (Jaramillo et al.2010), only one record of terrestrial ETM2 hasbeen reported from Vastan Lignite mine, India(Clementz et al. 2011).

Apart from its importance in understandingthe climate dynamics in a greenhouse globe, suchclimate extremes presumably played an impor-tant role in the biotic evolution also as severalmodern orders of mammals (artiodactyls, peris-sodactyls, and primates or artiodactyls, perisso-dactyls, and primates (APP) taxa) first appearednearly concurrently in the Holarctic continents(North America, Europe and Asia) during thisinterval (Gingerich 2006; Smith et al. 2006). How-ever, the first appearance datum of the APPtaxa in North America (Polecat Bench, Bighornbasin) and China (Hengyang Basin) show markedchronological discordance when compared with thehigh resolution carbon isotope stratigraphy. While,the appearance of APP taxa at North Americaoccurred within the PETM CIE body (Smith et al.2006), in China they appeared at the base of thePETM CIE (Bowen et al. 2002). Recent discoveryof exciting assemblages of terrestrial mammalianfauna, viz., euprimates (adapoids, omomyids, etc.),Laurasian artiodactyl Diacodexis, Perissodactyla,rodent Meldimys, primitive lagomorph, and manyother forms from the Vastan mine led to thesuggestion that the earliest mammals might havemigrated from southern Asia (e.g., China) toIndian subcontinent near the PETM (Rose et al.

2009). The mammal assemblage in the Ghazi for-mation, Pakistan is also suggestive of modernmammalian dispersal during initial India–Asia col-lision (Clyde et al. 2003). An alternative specula-tion is that many of these early modern mammalsmight have originated in island-India duringits northward drift towards Eurasia and latermigrated to northern continents after the India–Eurasia collision (Bajpai et al. 2008; Clementzet al. 2011). This has been termed as ‘Out of India’hypothesis in many recent literature (see Rustet al. 2010 for detail). Fundamental to this specu-lative hypothesis is the identification of the PETMinterval and the exact chronological assignment ofthe mammal layers relative to the PETM CIE inthe Vastan mine section. Here, for the first time,we report near-terrestrial equatorial PETM sec-tion with all subsequent EEHs within the CambayShale Formation at Vastan lignite mine, southernCambay basin, western India. Our study showsthat the mammal layer at Vastan is substantiallyyounger than the PETM, thus casting doubt aboutthe ‘out of India’ hypothesis.

2. Materials and methods

Sediment samples of Cambay Shale Formationwere collected from both 60 m thick exposed sec-tion of the Vastan mine face (21◦26.152′N and73◦06.968′E; figure 1b) as well as ∼100 m drillcore raised by the Gujarat Industrial Power Corpo-ration Limited (GIPCL) at Vastan. The compos-ite litholog was prepared using the ∼10 m thickupper coal seam (figure 2) and upper fossilifer-ous grey shale layer identified in both mine faceand core.

Late Paleocene–early Eocene carbon isotope stratigraphy 165

Figure 2. Field photograph of the Vastan mine section and representative composite litholog showing the position of mam-mal layer, Nummulites burdigalensis (Nb) zone and ETM2/H1 hyperthermal. The column to the left of the litholog showsthe actual sediment colours.

For δ13C analysis of bulk organic matter ∼1–50 mg decarbonated sample was combusted in aflash elemental analyser. The evolved CO2, puri-fied through a moisture trap, was measured for itsisotopic compositions in a Delta Plus XP contin-uous flow mass spectrometer (analytical precision±0.1�) at National Stable Isotope Facility, IndianInstitute of Technology, Kharagpur. For strontium(Sr) isotope, fossil shell samples were ultrasoni-cally cleaned, dried, leached in ultrapure 1 N HCland residue removed. Sr was separated from theleachate by conventional cation exchange columnchromatography and loaded onto a tantalum fila-ment. 87Sr/86Sr was measured in a Thermo FischerTriton thermal ionization mass spectrometer atthe KDM Institute of Petroleum Exploration,Dehradun. The measured ratios are normalized to86Sr/88Sr = 0.1194. All sample ratios were adjustedto measured 87Sr/86Sr ratio of NIST 987 standard.Nannofossils were separated by standard randomsettling technique, smear-slides prepared and stud-ied with a polarizing microscope. Selected slideswere gold sputtered and studied under scan-ning electron microscope (SEM) at Birbal SahniInstitute of Palaeobotany, Lucknow.

3. Results and discussion

3.1 Depositional environment ofthe Vastan sequence

Formed by intracratonic rifting, the Cambay basinhosts ∼8 km of fluvio-lacustrine sediments (with

minor marine intervals) as a result of episodic sub-sidence from late Cretaceous to Miocene period(Biswas 1987). The shale–lignite sequence atVastan, belonging to Cambay Shale Formation,was directly deposited over the Deccan Trap base-ment (Punekar and Saraswati 2010). The sequencecomprises alternate lignite and grey shale encas-ing thick (metre scale) wedge-shaped coquina-likemarine shell beds and centimetre to decimetrescale silt/fine sand lenses (figure 2). Dominant fine-grained sediments, anoxic to dysoxic facies (e.g.,coal/black-/grey-shale), general absence of tide orwave features, profuse bioturbations in grey shalesand lenticular silt/sand/shell beds indicate depo-sition in a possible lagoonal environment (Holz2003). In particular, the lagoonal beds at Vastancontain two prominent marine incursion horizons,the lower one yielding rich marine bivalve assem-blage at ∼200 m depth and the upper one at∼170 m depth yielding both marine bivalves as wellas larger benthic foraminifers (e.g., Nummulitesreported by Punekar and Saraswati 2010). Theseintervals possibly represent discrete high sea standswith more open ocean connectivity in this lagoon.It is, however, important to note that althoughmarine beds occur at certain levels, thinner lig-nite layers are present throughout the sequencesignifying a dominant near-terrestrial environment.

3.2 Chronology

In Vastan thermophilic calcareous nannofossil,assemblage first appears near the lower marine

166 A Samanta et al.

bivalve rich horizon at a depth of ∼215 m andextends up to ∼190 m and represented by Dis-coaster araneus (nannoplankton zone (NP) 9b toNP10a), Rhomboaster cuspis (NP9b to NP10a;Aubry 1999), Tribrachiatus bramlettei (NP10 toNP11; Martini 1971), and Fasciculithus tympani-formis (end of NP4 to NP9b; figure 3). Base ofT. bramlettei, D. araneus and R. cuspis typicallycoincides with the PETM, while F. tympaniformisterminates at the PETM. This unique associationof T. bramlettei, D. araneus, R. cuspis and F. tym-paniformis is globally assigned as the PETM (Raffiet al. 2005). Based on this evidence, we considerthe depth interval between 215 and 190 m belowthe Vastan mine section to be equivalent to thePETM. Larger benthic foraminifera Nummulitesburdigalensis burdigalensis and N. burdigalensiskuepperi occur in the upper marine horizon (160–170 m, Punekar and Saraswati 2010) correspond-ing to early shallow benthic zone (SBZ) 10. Basedon the latest magnetostratigraphy of Gradsteinet al. (2004) and re-calibration of the SBZ-10 byMochales et al. (2012), the time span of SBZ-10has recently been revised from 51.5 to 53.5 Ma(see later discussion). To ascertain the chronol-ogy of the sequence, we also carried out 87Sr/86Srratio of marine bivalves from both lower and upper

fossiliferous intervals of Vastan, which have excel-lently preserved pristine aragonitic shells (figure 4inset). The 87Sr/86Sr ratio of these shells variesfrom 0.707708 ± 4 to 0.707766 ± 4. These ratiosare similar to those reported by Clementz et al.(2011). Using the strontium isotope stratigraphiccalibration of McArthur and Howarth (2004), thenumerical best fit ages of these bivalves (red dotswith vertical bar, figure 4) range between ∼56.5and 52 Ma. Considering the new and published87Sr/86Sr data along with the biostratigraphic ages,it can be inferred that the age of the Vastansequence ranges from ∼56.5 to at least 52 Ma. Theabove chronology of Vastan is further supported bytheir corresponding δ13C chemostratigraphy (seelater discussion on carbon isotope stratigraphy).

3.3 Diagenesis and sources of organic matter

Two major uncertainties associated with the use ofbulk organic matter δ13C stratigraphy are (i) post-depositional diagenetic modification and (ii) faciesor lithology-dependent mixing of diverse sourcesof organic matter. Almost all the marine bivalvesat Vastan have exceptionally well-preserved arag-onitic shells (figure 4 inset). As discussed above,

Figure 3. Typical nannofossil biostratigraphic ranges across the PETM and light microscopic (1–5) and SEM (6–7) pho-tographs of their occurrences in Vastan at ∼200 m depth. (1) Tribrachiatus brameletti (Proto Decima et al. 1975),(2) Fasciculithus tympaniformis (Hay and Mohler 1967), (3–4) Rhomboaster cuspis (Bramlette and Sullivan 1961),(5) Discoaster araneus (Bukry and Percival 1971), (6–7) Rhomboaster cuspis.

Late Paleocene–early Eocene carbon isotope stratigraphy 167

Figure 4. Chronology of Vastan sediments based on stron-tium isotope ratios (87Sr/86Sr) of marine bivalves (red dots).Also plotted previously published ratios of Vastan carbon-ates by Clementz et al. (green dots, 2011) and data used byMcArthur and Howarth (2004; gray dots) for age calibration.Vertical bars represent analytical errors (±2σ). Inset show-ing photograph of preserved aragonitic bivalve shells fromwhich Sr ratios were measured.

these carbonates also preserved pristine Paleocene–early Eocene marine 87Sr/86Sr ratios. Biomarkerisotopes of Vastan resins even identified the plantcommunity at generic level (Dutta et al. 2011)suggesting minimal diagenesis. Thermochemolysisof the lignites suggest preservation of lignin com-pounds in these rocks indicating their derivationfrom terrestrial plants (Dutta et al. 2012). Apartfrom diagenesis, another factor that might poten-tially complicate the interpretation of δ13C stratig-raphy is the facies-dependent mixing of diversesource of organic matter. Different kinds of vege-tation might thrive on different sedimentary faciesnamely, proximal or distal part of a depositionalecosystem (e.g., river floodplain, bar or lagoonbank). No specific bias towards specific lithofacieson the frequency distribution of δ13C was observedindicating that isotopic compositions are facies-independent and can be used for palaeoclimaticinferences.

3.4 δ13C stratigraphy

Figure 5 shows the bulk organic matter δ13Cstratigraphy at Vastan. Five distinct negative CIEsare observed upward from the base of the section.The first major CIE occurs between 231.85 and

194 m depth with magnitude (Δδ13C, base to peakdifference in δ13C of the excursion) of 5.2�. Theother four CIEs occur at 152.5 m (Δδ13C = 2.2�),140.7 m (Δδ13C = 2.2�), 134.5 m (Δδ13C =1.6�), and 117 m (Δδ13C = 2.3�) depths. Usingthe Sr isotope ratios and partial δ13C profile, thepeak from a level close to 152.5 m in the Vastanmine section has already been identified byClementz et al. (2011) as ETM2 (green CIE infigure 6). Based on the 87Sr/86Sr ratio (as discussedearlier) and association of Tribrachiatus bramlettei,Discoaster araneus, Rhomboaster cuspis and Fasci-culithus tympaniformis; we interpret the lowermostand largest plateau like CIE at Vastan (Δδ13C =5.2�) as the PETM. Up in the section, the sec-ond excursion of 2.2� is found within the thick-est lignite seam at ∼152.5 m depth. From thepresence of Nummulites burdigalensis burdigalen-sis and N. burdigalensis kuepperi just below thisseam (figures 5, 6) Punekar and Saraswati (2010)earlier assigned it to be equivalent to early SBZ-10 (following Serra-Kiel et al. 1998). The earlierage of SBZ-10 (∼52.7–∼50.7 Ma) was calibratedagainst an old-time scale of Berggren et al. (1995).However, using the latest available GeomagneticPolarity Time Scale (GTPS; Gradstein et al. 2004),Mochales et al. (2012) showed that the base ofthe SBZ 10 is substantially older (∼53.5 Ma)than previously thought and lies within the mag-netic Chron C24n.2n. Based on this, the CIE at∼152.5 m can be considered as ETM2. However,unlike the PETM, it has not been possible toassign an absolute date for the ETM2. The dateof the PETM, i.e., 55.53 ± 0.05 Ma is now well-established using both the astronomical calibra-tion and absolute radiogenic isotope date of theEocene ash-17 layer from the ocean drilling pro-gram (ODP) section 1262 (see Westerhold et al.2012). On the other hand, no datable horizon hasso far been found near ETM2 and its age assign-ment has been done based only on the combinationof magneto-stratigraphy and orbital chronology.This suggests that the time gap between the PETMand the ETM2 is either 2.25 myr (spans ∼21 eccen-tricity cycle, Lourens et al. 2005) or 1.83 myr(spans ∼19 eccentricity cycle, Westerhold et al.2007). Considering 55.5 Ma absolute age of thePETM, the age of the ETM2 could be either∼53.25 or 53.67 Ma. The ranges of both SBZ-10 (green bar) and ETM2 (blue bar) are shownin figure 5, which shows an overlapping range.Based on these observations, we conclude that theCIE at ∼152.5 m depth as the H1/ETM2/ELMO(Lourens et al. 2005; Zachos et al. 2010; Clementzet al. 2011). The shape, amplitude and approxi-mate timing suggest that the three CIEs, overlyingthe ETM2, are possibly the H2, I1 and I2 (figures 5,6; Zachos et al. 2010).

168 A Samanta et al.

Figure 5. Lithologs along with bulk organic matter δ13C at Vastan. The δ13C stratigraphy is compared and correlated withcarbonate δ13C stratigraphy of ODP 1051 of Southern Ocean best recording the EEHs. Amplified magnitudes of the Vastansection compared to the marine records of both PETM and EEHs are clearly discernible. ETM2 (blue bar) and SBZ 10(green bar) age ranges show an overlap of about ∼0.25 Ma (for details see text).

The carbonate δ13C profile at ODP site 1051 inthe southern ocean, that records best the EEHs, isplotted with the δ13C profile of Vastan in figure 5.The dotted lines in figure 5 denote the correlationof the PETM and EEHs with the marine records.The CIEs in deep sea carbonates are severely atten-uated by dissolution effect due to ocean acidifica-tion (Nicolo et al. 2007; Smith et al. 2007), thusquestioning the magnitude of these events andtheir global nature. The present study, for the firsttime, documents all five hyperthermal/CIE events,including the PETM, in a near-terrestrial equato-rial sequence with Δδ13C of the CIEs larger thanor equal to those recorded elsewhere and suggestthese to be global in nature. Figure 6 shows thecorrelation of the Vastan δ13C profile with twopublished terrestrial sections from Claret, Spainand Honeycombs, North America (Domingo et al.2009). The PETM interval at all these three ter-restrial sections are similar and much expanded(∼30–40 m) compared to the marine PETMs. Anadditional CIE is observed immediately after thePETM at ∼190 m in Vastan. Such an excursion

has also been observed in Claret and Honeycombssections, although its significance is not fullyunderstood. Identification of the PETM and otherEEHS at this location provides evidence of theearly Cenozoic carbon cycle perturbations even intropical terrestrial realm. The large magnitudes ofthe CIE of either the PETM (∼5.2�) or otherEEHs at Vastan suggest that (1) the perturbationwas recurring in nature and (2) cannot possiblybe explained only by the dissociation of marinegas hydrates, since it would require an unrealisticinstability of hydrate reservoir over a long periodof ∼3–4 Myr (i.e., 55–52 Ma). Recent studies infact suggest an alternative source of methane fromterrestrial swamps and peat lands triggered duringthis ancient super-greenhouse condition (Pancostet al. 2007; DeConto et al. 2012). Estimationbased on the global distribution of coal-bearingfacies suggest that during the late Paleocene–earlyEocene aerial extension of wet land/peat land was∼3 times higher than today (Sloan et al. 1992;Beerling et al. 2011). Strong evidences exist aboutenhanced methane emission from wet land due to

Late Paleocene–early Eocene carbon isotope stratigraphy 169

Figure 6. High resolution record of bulk organic matter δ13C of Vastan compared with continental Claret (Spain; in red)and Honeycombs (North America; in blue) section. Previously reported ETM2/H1 CIE at Vastan is also shown (in green).Note that the mammal horizon at Vastan is much younger than either the PETM or Holarctic taxa of China (discussionin text).

ongoing global warming (Turetsky et al. 2008).If so, methane from wet land could easily injectdepleted carbon into the ocean–atmosphere systemcausing hyperthermal CIEs during the late Pale-ocene and early Eocene. Indeed, recently observeddepletion in δ13C of hopanoids (a biomarker ofmethanotrophic bacteria) across a lignitic PETMsequence (Pancost et al. 2007) supports significantrole of methanogenic carbon emission from wetland and peat land that was much more extensivein a warm early Eocene globe.

3.5 Antiquity of modern Indian mammals

Detection of PETM at Vastan has an added impli-cation. Our data, for the first time, reports thePETM interval at Vastan and clearly shows thatthe mammal layers are significantly younger thanthe PETM interval (figure 6). Considering theage of termination of the PETM (∼55.3 Ma)and ETM2 (∼53.7 or ∼53.25 Ma; Lourens et al.2005; Zachos et al. 2010) and the intervening

sediment thickness (without decompacting), theage of the mammal layer is close to a million yearsyounger than the PETM, thus raising doubts aboutthe ‘out of India’ hypothesis. Although molec-ular clock estimation suggested origin of manymodern vertebrate lineages and mammalian taxain an isolated drifting Indian continent (Krauseand Maas 1990; Bossuyt and Milinkovitch 2001)which later dispersed and colonized in rest ofthe world, the revival of ‘out of India’ hypo-thesis took place when oldest (∼55 Ma) Anthro-poidea (Anthrasimias gujaratensis) was claimedto have been discovered in Vastan (Bajpai et al.2008; Clementz et al. 2011). Assignment of thisAnthrasimias, on the basis of differentiating smallcusps in isolated teeth, has been questioned andconsidered to be unreliable phyllogenetic indicator(Rose et al. 2009). An exhaustive analysis of Vastanfauna suggests that none of the primates namely,omomyids, adapoids, Asiadapines, etc. eitheroriginated in India or are more primitive thantheir counterparts found elsewhere (Rose et al.2009). The only unequivocal evidence of oldest

170 A Samanta et al.

Asian mammalian fauna comes from HengyangBasin, Hunan province of China, where diverseAPP taxa have indeed been found from horizonsnear the PETM carbon isotope excursion (Bowenet al. 2002; figure 6). Our data suggest that theVastan mammals appeared at least a million yearslater than those of China (figure 6) and questionsthe antiquity of Indian mammals. Thus, pendingthe discovery of still older (at or pre-PETM) fossilrecords, the present work seriously raises questionsabout the antiquity of Vastan mammals. As sug-gested by Rose et al. (2009), most likely these faunamigrated into India, near the PETM, after theestablishment of land-bridge due to India–Eurasiacollision.

4. Summary

High resolution carbon isotope (δ13C) stratigra-phy, nannofossil, and 87Sr/86Sr isotope ratio offossil carbonate shells of lagoonal lignite beds ofVastan area from the Cambay Shale, India havebeen studied. Data show complete preservation ofall the early Eocene CIE events (viz., H1/ETM2/ELMO, H2, I1 and I2) including the PETM, hith-erto unknown from the tropical terrestrial records.The δ13C chemostratigraphy further suggests thatthe present early Eocene Indian mammalian fossilbearing horizon, recently discovered at Vastan, isat least ∼1 Myr younger than the PETM. Unlessolder (at or pre-PETM) fossil mammals are found,the present dataset does not support the ‘out ofIndia’ hypothesis of earliest appearance of mod-ern mammals and their subsequent dispersal to theHolarctic continents.

Acknowledgements

This work forms part of the Ph.D. thesis of ASamanta, who thanks IIT, Kharagpur for the fel-lowship. A Sarkar thanks Department of Scienceand Technology (DST), New Delhi for fundinga research project on Paleogene sediments ofwestern and northwestern India, under which thepresent work was carried out. Bulk isotope datawere generated in the mass spectrometer labo-ratory of IIT, Kharagpur funded by the DST.SSR thanks the Executive Director, KDMIPE forgiving permission for Sr isotope analysis and col-laboration. Discussion with Prof. J Serra-Kiel,University of Barcelona was immensely help-ful in improving the manuscript. The authorsthank Gujarat Industrial Power Corporation Lim-ited (GIPCL) for giving permission to carry outthe field work at Vastan mine area and kindlyproviding the drill core samples.

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MS received 16 May 2012; revised 9 July 2012; accepted 9 July 2012

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*For correspondence. (e-mail: jyotsana_rai@yahoo.com)

Early Callovian nannofossils from the Kuldhar section, Jaisalmer, Rajasthan Jyotsana Rai* and Rahul Garg Birbal Sahni Institute of Palaeobotany, 53, University Road, P.O. Box 106, Lucknow 226 007, India

Jurassic nannofossils are scarcely known from the Indian subcontinent. We report here a well-diversified and moderately preserved Early Callovian nannofossil as-semblage comprising twenty-one species recovered from the Kuldhar Member, Jaisalmer Formation, Raja-sthan, western India, which is exposed along the banks of the Masrudi river, adjacent to the ruins of the Kuld-har village. The assemblage demonstrates a typical Tethyan aspect and can be precisely calibrated with standard low-latitude nannofossil Ansulasphaera hel-vetica (NJ 12) zone. The Kuldhar Member is rich in mega and microfossils, including datable ammonoids, brachiopods, pelecypods, benthic foraminifera, ostra-cods, nannofossils and ichnofossils. Though the age of these sediments is traditionally based on ammonoid evidences, nannofossils provide another potentially reli-able tool for dating and correlation. Keywords: Early Callovian, Jaisalmer Formation, Kuld-har Member, nannofossils. MARINE Jurassic rocks are widespread in Kutch and Jais-almer (Rajasthan), on the western margin of the Indian subcontinent (Figure 1). The Jurassic successions in these areas are represented by siliciclastic rocks interspersed with carbonates of shallow, neritic facies in a southerly extending embayment of the Tethys. Tectonically, the Jaisalmer basin is divisible into three zones: (i) the raised Mari-Jaisalmer Arch extending through the central part of the basin into NW–SE trend flanked by (ii) the synclinal Sahgarh basin to the south and southeast and northeast, and by (iii) the monoclinal Krishangarh sub-basin to the north and northeast1,2. The area under study occupies the southeastern part of Mari-Jaisalmer Arch, where a number of sedimentary formations are exposed on the peneplained Pre-Cambrian basement. The terrain being desertic, large parts of outcrops are covered with sand and alluvia. In the Jaisalmer Basin, age of the surface Jurassic sediments is from Bajocian to Tithonian with intermittent hiatuses1–6. The marine Jurassic sediments of Jaisalmer (Rajasthan) are well known over a century for their excellent outcrops and classic ammonite fauna7,8. Although the Bathonian–Callovian succession in Jaisalmer is comparatively much less thicker than the ad-joining Kutch Basin9,10, a fairly close stratigraphic simi-larity both in lithology and fossil contents is strikingly noticeable.

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Table 1. Genaralized mesozoic stratigraphy of Jaisalmer area (based on Oldham30, Narayanan1, Dasgupta2, JaiKrishna31, Pandey and Fürsich3)

Age Formation Member Gross lithology/facies

Aptian Habur Marine coquinoidal limestone and sandy limesone

Neocomian Pariwar Sandstone and shale alternation with plant fossils and fossilized tree trunk

Tithonian Bhadasar Mokal Coarse to fine-grained sandstone, marine in the Kolar Dunger lower part grading into nonmarine sequence at the top

Kimmeridgian Baisakhi Rupsi Marine shale and sandstone alternations Ludharva Baisakhi

Bajocian to Jaisalmer Kuldhar Alternations of marine arenaceous limestone and Oxfordian Badabag calcareous sandstones Fort Joyan Hamira

Lias to Bajocian Lathi Thaiyat Sandstones with plant fossils Odania

Proterozoic Older sediments

Figure 1. Map of part of Jaisalmer Basin displaying exposition of various Mesozoic formations (after Dave and Chatterjee14).

Geology of the Jaisalmer Basin has been studied by several workers1,2,11,12. In the present study, rock-strati-graphic classification of DasGupta2 (Table 1) is followed. Detailed ammonoid biostratigraphy of Jurassic sediments of the Jaisalmer Basin is also available13,14. Besides am-monites, which are known to be the best chronometers for Jurassic successions13–15, various groups of microfossils, viz. benthic foraminifers16–19, ostracods20,21, holothuroids22, calcareous nannofossils23 and megafossils like corals3 are

also documented from Jaisalmer area. Nannofossils known so far from the Kuldhar section23 have been limited as criti-cal marker taxa have remained unrecorded. This necessi-tated a detailed nannofossil study of the Kuldhar section. The Kuldhar section is well exposed on the flanks of the dry Masrudi river, adjacent to the ruins of the aban-doned Kuldhar village, about 18 km southwest of Jaisalmer (Figure 2). The ca. 16 m thick succession in the lower part consists of fossiliferous limestone, calcareous sandstone, marl and shale with several oolitic levels, characteristi-cally displayed in alternating hard and soft bands (Kuldhar Member). The overlying Jajiya Member is represented by limestone, shales with sandstones at the top with large-sized rhynconellids and terebratulids, besides ammonoids

Figure 2. Sections exposed around Masrudi nadi near Kuldhar ruins and detailed litholog of the KD section.

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Figure 3. All forms are photographed under single polarizer or crossed polarized illumination using gypsum plate. All forms are magnified X2000. A1–A5, Stephanolithion hexum Rood & Barnard, 1972; B1, S. bogotii Deflandre, 1939 ssp. bigotii; B2, B3, S. speciosum Deflandre in Deflandre & Fert, 1954 ssp. speciosum; B4, B5, S. hexum Rood & Barnard, 1972; C1, C2, S. bogotii Deflandre, 1939 ssp. maximum Medd, 1979; C3, Watznaueria ovata Bukry, 1969; C4, W. barnesae (Black, 1959) Perch–Nielsen, 1968 and Calolithus martelae Noël, 1965; C5, Watznaueria sp.; D1, ?Basal disc of Discorhabdus sp.; D2, Triscutum beaminsterensis Dockerill, 1987; D3–D5, Ethmorhabdus gallicus Noël, 1965; E1, Watznaueria britannica (Stradner, 1963) Reinhardt, 1964; E2, Cyclagelosphaera margerelii Noël, 1965; E3, Watznaueria manivitae Bukry, 1973; E4, E5, Ansulasphaera helvetica Grün & Zweili, 1980; F1, W. barnesae (Black, 1959) Perch–Nielsen, 1968; F2, C. martelae Noël, 1965; F3, F4, W. ovata Bukry, 1969; F5, Coccosphere of Watznaueria sp.; G1, Zeugrhabdotus sp.; G2–G4, Z. erectus (Deflandre in Deflandre & Fert, 1954) Reinhardt, 1965; G5, Diadorhombus minutus Rood et al., 1971; H1, H2, Crepidolithus perforata (Medd, 1979) Grün & Zweili, 1980; H3, Lothar-inguis sigillatus (Stradner, 1961) Prins in Grün et al., 1974; H4, H5, L. crucicentralis (Medd, 1971) Grün & Zweili, 1980.

and crinoids22. It is unconformably overlain by ca. 6 m thick, poorly fossiliferous gypseous shale with thin, fossilifer-ous, hard calcareous clay bands (lower part of Baisakhi Member) not exposed in the studied section. The Kuldhar Member abounds in mega- and micro-fauna (ammonites, belemnites, brachiopods, bivalves, serpulids, echinoderm fragments, benthic foraminifers, ostracods and calcareous nannofossils) besides containing some extensively bur-rowed horizons rich in Thalassinoides and Zoophycus ichnotaxa. The entire succession is exposed in patches along the 1.5 km stretch of the dry river bed. The present study is confined to the basal part of the Kuldhar Member (section KD). Detailed lithology, thickness and sample positions are given in the litholog (Figure 2). The hard bands yielded poor nannofossils displaying little recrys-tallization; however, shales are rich in datable marker nannofossils.

For preparation of permanent slides of eight samples (BSIP museum numbers 13083–13090), a small fraction of sample (scooped with the help of a scalpal) is soaked in neutral distilled water in a clean porcelain crucible. Few drops of the turbid suspension are spread over a clean glass slide as a thin film and mounted with Canada balsam. Nannofossils were studied using Leitz polarizing microscope under the 100/1.32 oil immersion objective both under normal (using single polarizer) and crossed polarized illuminations using gypsum plate. Nannofossil assemblage recovered from the basal part of the Kuldhar Member is moderately preserved and well-diversified (Figure 3). Nannofossils are present almost throughout the section, but are not numerically abundant (Figure 4). The assemblage comprising twenty-one species, is dominated by long-ranging taxa, viz. Watznaueria barne-sae, W. britannica, W. ovata and Cyclagelosphaera marge-

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relii (at a few levels only). Predominace of variable-sized Watznaueria spp. is noticeable. Occurrence of A. helve-tica, S. bigotii, S. hexum and S. speciosum in the assem-blage is significant as it permits calibration with Ansula-sphaera helvetica zone (NJ 12) and Stephanolithion bigotii bigotii zone (NJ 13)24,25 of Early Callovian age. LAD (last appearance datum) of S. speciosum and FAD (first appearance datum) of W. manivitae and C. perfo-rata in the lower part further help demarcate the base of zone NJ 13. LAD of S. octum near the top restricts the age of the section to Early Callovian (Figure 4). The assem-blage displays a typical Tethyan aspect due to the com-mon occurrence of Watznaueria and Stephanolithion species. The Kuldhar nannofossil assemblage shows close com-parison with that recorded from the Jara Dome in Kutch26 and East Karakoram Block27 in the presence of marker A. helvetica, revealing strong potential for recognition of a widespread early Callovian transgressive event in the Indian subcontinent, as a consequence of global eustatic rise dur-ing this time28,29. Thus the present nannofossil record is quite significant because of its potential in age determina-tion and long-distance correlation. Nannnofossil data from Kuldhar section closely corre-spond with evidence of ammonite as occurrence of Mac-rocephalites madagaskeriensis, M. chariensis and M. semilevis is recorded from the basal part of the Kuldhar section, indicating Upper Bathonian–Early Callovian age13. Lack of ammonites in the underlying succession (Badabag Member) precludes demarcation of Batho-nian/Callovian boundary. However, based on the occur-rence of endemic benthic foraminifers, Middle to Upper Bathonian age for the underlying Badabag Member has been suggested18. Placement of Bathonian–Callovian boundary is tentatively suggested on the basis of benthic foraminifers19. Recovery of a moderately preserved nanno-fossil assemblage recovered from the Bara Bag section (authors’ unpublished data) is significant in this context

Figure 4. Stratigraphic distribution of selected nannofossils in Kuld-har section.

and may be expected to provide evidence for placement of the Bathonian–Callovian boundary. An arm of the Tethys that spread southwards and inun-dated the western margins of the Indian Shelf in Jaisal-mer and Kutch is known as the ‘Ethopian Gulf’. It was the site of a shallow marine embayment which recorded a highly fossiliferous, mixed siliciclastic and carbonate succession in both areas. Pronounced endemism is re-corded in the Bathonian benthic foraminifera of Jaisalmer, containing typical Saudi Arabian elements (Pseudomar-sonella, Riyadhella, Pfenderina)18. Strongly endemic ammonite fauna during Callovian in the entire ‘Ethiopian Gulf’ has led to recognition of an ‘Indo-East African Province’13. Occurrence of several cosmopolitan and boreal elements in the present nannofossil assemblage is, there-fore, significant for long-distance correlation as well as in the palaeobiogeographic context.

1. Narayanan, K., Problems of stratigraphy of the Rajasthan shelf. In Proceedings of the Symposium on Problems of Arid Zone of In-dia, Govt of India Publ, New Delhi, 1964, pp. 92–100.

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3. Pandey, D. K. and Fürsich, F. T., Bajocian (Middle Jurassic) age of the Lower Jaisalmer Formation of Rajasthan western India. Newsl. Stratigr., 1994, 30, 75–81.

4. Kachhara, R. P. and Jodhawat, R. L., On the age of Jaisalmer Formation, Rajasthan, India. In Proceedings of IX Indian Collo-quium on Micropalaeontology Stratigraphy, Udaipur, 1981, pp. 235–247.

5. Pandey, D. K., Kashyap, D. and Choudhary, S., Microfacies and depositional environment of the Gharoi section (upper Jaisalmer Formation), west of Baisakhi village, Jaisalmer Basin, Rajasthan. In Proceedings of the National Seminar on Oil, Gas and Lignite Scenario with Special Reference to Rajasthan, Jaipur, 2005, pp. 117–130.

6. Pandey, D. K., Kashyap, D. and Choudhary, S., Depositional his-tory of the early part of the Jurassic succession on the Rajasthan Shelf, western India. Prog. Natl. Sci., 2006, 16, 176–185.

7. Pandey, B. and Krishna, J., New ammonoid data: Implication to the age of Bhadasar Formation of Jaisalmer, Rajasthan. Bull. Pure Appl. Sci., 1996, 15, 31–36.

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10. Fürsich, F. T., Oschmann, W., Singh, I. B. and Jaitly, A. K., Hardgrounds, reworked concretion levels and condensed horizons in the Jurassic of western India: Their significance for basin analysis. J. Geol. Soc. London, 1992, 149, 313–331.

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*For correspondence. (e-mail: myadava@prl.ernet.in)

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ACKNOWLEDGEMENTS. We are grateful to Dr Naresh C. Mehro-tra, Director, Birbal Sahni Institute of Paleobotany (BSIP), Lucknow for facilities and encouragement. We thank Prof. Jai Krishna, Banaras Hindu University, Varanasi for discussions and P. K. Bajpai, BSIP for preparation of figures. Constructive comments from the reviewers have helped in improving the manuscript. Received 16 August 2005; revised 21 October 2006

Evidences of early human occupation in the limestone caves of Bastar, Chhattisgarh M. G. Yadava1,*, K. S. Sarswat2, I. B. Singh3 and R. Ramesh1 1Physical Research Laboratory, Navrangpura, Ahmedabad 380 009, India 2Birbal Sahni Institute of Palaeobotany, 53, University Road, Lucknow 226 007, India 3Department of Geology, University of Lucknow, Lucknow 226 007, India

We record the preservation of burnt earth, charcoal and plant remains (both wild and domesticated) in Kotum-sar and Dandak caves, Kanger Valley National Park, Bastar district, Chhattisgarh. Radiocarbon dates of the charcoal remains suggest that these caves were dwelling sites for prehistoric man during 6940–4030 yrs BP. The presence of grains and seeds at ~ 7000 yrs BP indicates domestication of plants and initiation of agricultural activity by prehistoric man in the region. Preliminary results reveal that the caves were abandoned around 4000 yrs BP, coinciding with the weakening of the southwest monsoon. Keywords: Caves, plant domestication, prehistory, radio-carbon, southwest monsoon. KOTUMSAR and Dandak are cave complexes (19°00′N, 82°00′E) in the spur of the forested hilly area in Kanger Valley National Park, Bastar district, Chhattisgarh (Fig-ure 1). The caves, which are part of the western foothills of the northeast–southwest trending ranges (Kanger lime-stone of Indravati group of rocks of Upper Proterozoic)1, were formed by the dissolution of limestone bedrock. The important rock types in the area are limestone, purple shale and quartzite. Speleothems from these caves are being investigated for palaeomonsoon reconstruction2. The Ko-tumsar cave is around 330 m in lateral extent with several well-developed chambers and passages up to 20–70 m wide. The Dandak cave is located within ~ 5 km distance from the Kotumsar cave and has a lateral extent of about 200 m with 15–20 m wide passages. There are two cham-bers that are connected through a ~ 0.5 m narrow duct. The Kotumsar cave opens in the southeast and the Dandak in the west of the dense reserved forest. These caves are located on two isolated hills. Presently, the area is inhabited by tribal people (Dhurva), who sustain on agrarian econ-omy and minor forest produce. The geomorphological posi-tion of the caves and the presence of dense forest suggest an ideal habitat for prehistoric human occupation. During our investigations we came across evidences of controlled fire that was preserved as burnt earth, patches of charcoal mixed with soil and grass, suggesting human occupation.

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Response Organized opposition to infrastructure projects in India does not seem to suffer from shortage of funds. Therefore, it is a valid question to ask whether environ-mental activism, at least some of it, is driven by non-environmental considera-tions. Still, if Rauf Ali thinks all this is only a ‘state of mind’, then it can be easily cured by disclosing who pays for ob-structing infrastructure projects in India. Why is that such a closely guarded secret? Just as Ali is anguished that, in the context of saving tigers, the opinion of ‘a group of non-scientists’ has prevailed, likewise we too felt aggrieved that the group which met in Bangalore and went

public with some theories about ILR, did not include a single water-resources en-gineer. Ali’s comment that ‘… at least one economic analysis shows that the costs of pumping the water uphill will make the project unviable’, is based on a paper N. Pelkey, a professor of environmental sciences and information technology in Pennsylvania. He is not a known authority on strategic planning for food, water and energy security for India, wrote his paper before the feasibility reports were made public, thus perhaps without reading them. But Ali seems to think that such a paper by a foreigner from whatever discipline is sufficient to trash 25 years of work by

a team of more than a hundred Indian water-resources engineers in the NWDA, CWC and other specialized institutions of the Government of India – say 2500 engi-neer-years of work. In that case, since food and energy security has strong strategic implications, whenever India plans major infrastructure projects, one can find papers, and rather easily, that will seek to trash the projects.

CHETAN PANDIT

Indian Water Resources Society – Delhi Center, C/o Upper Yamuna River Board e-mail: cm_pandit@hotmail.com

Nannofossil assemblage in Kutch Jyotsana Rai’s1 report on the occurrence of nannofossils of Albian age from a plant bed of the Bhuj Formation is interesting and significant. It is an accidental but impor-tant discovery. She has rightly stressed its importance on the age and environ-ment of deposition of the Bhuj Formation. However, conclusions drawn by her on these two aspects raise controversies and need to be discussed. I had reviewed this paper. Considering the limitations of the study, I suggested modifications in order to avoid contradictions with the existing field data and proven facts. However, it appears that my comments and sugges-tions were not taken into account while revising the manuscript. For the benefit of the researchers I feel it is necessary to explain here the anomalies created by rash conclusions drawn on limited data. Two important conclusions drawn are: (i) The nannofossil assemblage indicates early Middle Albian age of the Bhuj Formation (referred as Bhuj ‘Member’ in the text by Rai); (ii) The presence of nanno-fossils confirms the marine environment of the Bhuj Formation supporting ‘an un-interrupted marine succession from at least Late Bajocian to early Middle Albian in Kutch basin’. The following points need to be noted for discussion: 1. Occurrence of nannofossils is limited,

only one sample out of two collected from a shale bed in the Bhuj Forma-tion yielded nannoforms.

2. Middle Albian age of the Bhuj Forma-tion has been determined on the basis of one sample only from the Lower Member of the Bhuj Formation in Central Mainland, which is equivalent to the Neocomian Ghuneri Member in Western Mainland, which occurs below the Aptian Ukra Member of the forma-tion.

3. The sample comes from a fossiliferous horizon, which is rich in well-preserved terrestrial plant fossils. The excellent state of preservation of the leaves speaks of provenance proximity and thereby the environment.

4. Association of terrestrial plant fossils and marine nannofossils together in a bed is baffling and needs to be explained.

5. The horizon from where the nanno-fossil-bearing sample was collected is overlain by an intensely bioturbated zone which is devoid of nannofossils as also the barren shales below it.

6. The sandstone-dominated Bhuj Forma-tion, which is interpreted as marine deposit, is barren of fossil fauna but rich in fossil flora occurring in shale beds.

Age of Bhuj Formation: In the type area around Bhuj the formation is 400 m (+) thick and divided informally into two members, lower and upper2,3. The formation thickens enormously towards the west and in Gadhuli–Ghuneri area attains a thick-ness of over 900 m. In this area the formation comprises three members –

Ghuneri, Ukra and Upper in ascending order. The palyno-assemblage indicates Neocomian and Albian to (?)Santonian ages for the Ghuneri and Upper members respectively, whereas the ammonite index and absolute dating determined the Aptian age of the Ukra Member. The Neocomian age of the Ghuneri Member is also sup-ported by the ammonite index4. The Ghuneri and Upper members have the same litho-facies association, distinguished only by the local occurrence of Ukra Member bet-ween them. As the green, glauconitic shales and marl beds of Ukra Member pinch out, it is difficult to distinguish the two members. Both merge into one formation that continues eastward in the rest of the Mainland as the Bhuj Formation2. This formation comprises more than half of the total thickness of the Mesozoic suc-cession. Detailed mapping by tracing of the marker-defined litho-units (see figure 10 in Biswas3) established that the Lower Member of the Bhuj Formation of the type area changes laterally into the facies of the Ghuneri Member as the formation thickens westward. Several dark grey, carbonaceous shales with well-preserved fossil-leaf impressions and carbonized plant remains, occur at different levels within the formation. The megaflora and palynomorph (the formation is rich in microflora also) indicate Neocomian age for the Bhuj Formation5 (mainly Lower Member in the type area), which agrees with the stratigraphic position explained above. The reported occurrence of the

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nannofossil is from one of the plant beds of the Lower Member exposed near Jakh temple, 25 km west of Bhuj. Apparently, Rai had not taken note of the precise stratigraphic location of the sampled bed since she followed a classification4,6, which is more concerned with the nomenclature priority than the ground reality described above. This misled Rai to believe that Albian ‘Bhuj Member’ (Upper Member2) continues eastward in the Bhuj area, and the sample was collected from the lower part of the member, whereas in reality the sample was collected from the Neo-comian Lower Member (= Ghuneri Mem-ber). Thus, the reported occurrence of Mid-Albian nannofossils in rocks below the Aptian Ukra beds created a stratigraphic anomaly. I would, therefore, suggest that a definite conclusion regarding the Al-bian age of the Bhuj Formation in the type area should be postponed till all the plant and other shale beds are examined for the nannofossils. Depositional Environment of Bhuj For-mation: Presence of marine fossil in sediments does not necessarily mean that the deposit is holomarine. There are re-ports of occurrence of micro-fauna in ae-olian and fluvial deposits7,8. It is difficult to accept that the Bhuj Formation with well-preserved Upper Gondwana floral assemblage but barren of fossil fauna is holomarine deposit as interpreted by some workers9, whose views Rai has tried to validate by the reported single occurrence of marine nannofossils. She does not dis-cuss the contradictory evidence presented by the well-preserved plant fossils and marine nannofossils in the same bed. Proponents of marine deposition4,9 based their opinion mainly on the repeated oc-currence of trace fossils and the biotur-bated ferruginous beds in the formation. They tried to explain the absence of hard-bodied fossils by desolution processes, but do not mention the absence of micro-fauna and preservation of fragile terres-trial plant fossils in the so-called marine sediments. Mere presence of bioturbated zones or trace fossils does not evince a ma-rine origin for the host sediments. Trace fossils represent behavioural traits of or-ganisms and it is an established fact that like behaviour can be seen in all types of environments10. Detailed study of the trace fossils reveals that they are typi-cally restricted occurrence of ichno as-semblage in transitional environments (K. G. Kulkarni, pers. commun.).

The Mesozoic sequence typically repre-sents a transgressive-regressive megacy-cle11,12. The early Middle Jurassic trans-gressive sequence is characterized by highly fossiliferous shale–limestone–sandstone litho-association. The upper Late Jurassic–Early Cretaceous, thick regres-sive sequence (Bhuj Formation) is pre-dominantly sandy and barren of fossil fauna, but rich in fossil flora and ichno-fossils. Based on detailed studies and ex-tensive mapping, the Bhuj Formation has been interpreted as a wave-dominated es-tuarine palaeo-delta with well-developed aggradational/progradational sequences during normal regression of the sea11,12. The delta prograded westward progres-sively shifting the wavefront, which left the marine (tidal) signatures like biotur-bated sediments and occasional mollusk shells (poorly preserved) across the basin. In the delta front zone in Western Mainland, the fossiliferous Ukra Member represents a short transgressive break in the delta progradation during a high stand. In the east, thick sequences characterized by multistoried stacks of current-bedded sand-stones with frequent channel cut and fills represent the proximal fluvial facies of the formation11. Therefore, the conclu-sion by Rai that ‘an uninterrupted marine succession from Late Bajocian to Middle Albian occurs in Kutch Basin’, is only partially true for the western end of the basin where the transitional facies of the Lower Member grades into the coastal facies of the Ghuneri Member in the delta front. Once it is understood that the host rocks are deposits of transitional envi-ronment, it is not difficult to explain the apparently contradictory occurrence of plant and marine fossils together in a carbona-ceous shale bed. In estuarine delta envi-ronment tidal currents penetrate deep into the hinterland during high tides. Fur-ther, penetration of tidal current is deeper over the prograding delta lobes during sea-level highstands in fluctuating condi-tions. In the present case, tidal current during high tides carried the planktonic nannofossils towards the hinterland over the swampy lower delta plain, where these tiny fossils were trapped with the leaves and other plant remains in lakes and local pools. In fact, such occurrence is expected in tide-dominated prograding delta front

and provides a supporting evidence for deltaic environment of deposition11,12.

1. Rai, Jyotsana, Curr. Sci., 2006, 91, 519–526.

2. Biswas, S. K., Geology of Kutch, vols I and II, Spl. Publ. KDMIPE, ONGC, De-hradun, 1993, p. 415.

3. Biswas, S. K., Q. J. Geol., Min. Metall. Soc. India, 1977, 49, 1–52.

4. Krishna, J., Newsl. Stratigr., 1991, 23, 141–150.

5. Venkatachala, B. S., Palaeobotanists, 1969, 18, 75–86.

6. Krishna, J., Singh, I. B., Howard, J. D. and Jafar, S. A., 1983, 305, 790–792.

7. Biswas, S. K., Sediment. Geol., 1971, 5, 147–164.

8. Raj, Rachna and Chamyal, L. S., J. Palae-ontol. Soc. India, 1998, 43, 55–67.

9. Howard, J. D. and Singh, I. B., Palaeo-geogr., Palaeoclimatol., Palaeoecol., 1985, 52, 99–122.

10. Ekdale, A. A., Bromley, R. G. and Pem-berton, S. G., Short Course No. 15, Society of Economic Paleontologists and Minera-logists, Tulsa, OK, 1984, p. 317.

11. Biswas, S. K., In Sedimentary Basins of India, Tectonic Context (eds Tandon, S. K., Pant, C. C. and Casshyap, S. M.), Gyano-daya Prakashan, Nainital, 1991, pp. 74–103.

12. Biswas, S. K., Q. J. Geol., Min. Metall. Soc. India, 1981, 53, 56–85.

S. K. BISWAS

201/C, ISM House, Thakur Village, Kandivali (East), Mumbai 400 101, India e-mail: sanjibkbiswas2001@yahoo.co.in

Response: S. K. Biswas, a name synonymous with Kutch stratigraphy has always been a source of inspiration throughout my res-earch career in the Kutch basin and his comments on my paper are welcome. I wish to add here that the suggestions and corrections by the two referees for the revision of the manuscript were contrast-ing. I modified the manuscript based on these comments. However, many of the comments were not valid and hence not incorporated. It may be added here that lithostratigraphic mapping of Kutch was done by Biswas1. Later work on palaeo-biology and depositional facies has pro-vided a more precise interpretation on depositional environment2. The queries raised by Biswas are addressed point-wise below. The present rare but important finding throws light on the precise age and envi-ronment of part of Umia Formation ex-posed in this part of the succession. 1. The nannofossil assemblage recorded

in my study, although only from one

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sample, gives a precise age for Bhuj sediments in the eastern part of Kutch. Earlier ages were only presumptions without any data.

2. The early Middle Albian age for Bhuj Member given by me is based on pre-cise global nannoplankton markers. The age of Ukra Member in the Western Mainland based on ammonoids is Ap-tian–Albian2 and not Aptian only as claimed by Biswas. The lithological boundaries are not time boundaries, hence age of the central mainland suc-cession cannot be determined with precision from a correlation with west-ern Kutch, as suggested by Biswas.

3. The nannofossil-yielding samples of my study come from a carbonaceous shale unit. This lithofacies are inter-preted as deposits of a coastal lagoon3. Coastal lagoons mostly contain high content of plant debris along with ma-rine fauna. There is no ambiguity in interpretation. Occurrence of nanno-fossil along with plant debris supports coastal lagoon depositional environment. Biswas argues that plant fossils are well preserved. My study clearly indicates that the plant debris is poorly preser-ved (impression and not compression) and shows evidence of high bacterial decay.

4. As mentioned above marine nanno-fossils and other marine fossils can occur together with plant fossils in a coastal lagoon and near-shore environ-ments, and there is nothing baffling about it.

5. The bioturbated zone and barren shales below are highly oxidized and non-cal-careous. Such lithologies do not pre-serve nannofossils.

6. World over, there are thick coastal sandy sequences deposited in a marine sys-tem which do not preserve marine fauna (I. B. Singh, pers. commun.). Preserva-tion of plant fossils within Bhuj Member is in lagoonal deposit. Bhuj sandstone has also yielded marine bivalve Indo-trigonia4.

Age of Umia (Bhuj) Formation: I have followed the traditional names (Patcham, Chari, Katrol and Umia formations)5. Later classification (Jhurio, Jumara, Juran and Bhuj formations)1 has inherent prob-lems as discussed by others. The purpose of the present communication was not to discuss the merits of various classifica-tion schemes. Bhuj Formation has been divided into three members in the western part of

Kutch (Ghuneri, Ukra and Upper)1. The Ghuneri and Upper members are similar in character. The Ukra Member contains ammonoids of Aptian–Albian2,6. In the central part of Kutch two informal Lower and Upper members of the Bhuj Forma-tion (= Umia Formation) are erected1 without a boundary between them. For the sake of convenience and lithological similarity, the Ghuneri and Upper mem-bers of western Kutch are correlated with the Lower and Upper members of central Kutch with no age control1. Palynotaxa can be used for palaeovegetation recon-struction and not for precise age deter-mination. Lithostratigraphic mapping of lithounits and marker beds cannot be taken as time lines. Lithological boundaries are mostly time-transgressive, especially when traced over long distances. Thus lithological corre-lation between western and central Kutch cannot be taken as time correlation. In this context Ukra Member (Aptian–Albian) now can be considered as time equivalent to nannofossil-yielding horizon (Albian) in central Kutch, as it is based on precise age determination by index fossils. It is now possible to correlate the central and western parts of Bhuj Formation of Kutch using time-marker fossils. Even if the present study is based on one sample, it can be more precisely used than lithostratigraphic and palynological correlation. I can understand the concern of Biswas, as it strongly changes his cor-relation scheme of the Bhuj Formation between western and central Kutch, but this is the way science progresses. Depositional environment of Umia (= Bhuj) Formation: If we try to see things with a pre-conceived notion, then it would be difficult to accept the marine nature of the Umia Formation. Since the Ukra Member contains ammonoids, there is no problem in accepting its age and marine nature. It is only the lower Ghuneri and upper Bhuj members, which are normally devoid of marine macro- or micro-fauna, that are considered as fluvial deposits1. Interpretation of coastal marine environ-ment of Bhuj Formation is based on de-tailed facies analysis of the succession, emphasizing facies sequences and other sedimentary structures3 (U. K. Shukla, un-published). Coastal lagoon, estuarine channel, tidal flat and shelf sheet sand depositional domains have been identi-fied and they occur in a predictive cyclic vertical succession3. Biswas uses a term holomarine. It is not used in depositional

environmental studies. In the interpreta-tion of depositional environment all the sedimentary features along with flora and fauna are considered. It is true that in the coastal zone marine microfossils are transported and deposited in coastal ae-olian domes, but the nature of sedimen-tary structures helps identify deposits as Aeolian. The bioturbated horizons identified7 in the Bhuj Formation were earlier interpreted as laterite horizons1. Now there seems a view that these laterite beds are bioturbated horizons. The Umia Formation (= Bhuj Formation) has been interpreted as deposits in embay-ment with many small estuarine channels formed in a tide-dominated shallow sea using detailed facies analysis (U. K. Shukla, unpublished). The need of the hour is to search all the plant beds of Umia Forma-tion for presence of nannofossil, with the hope to find nannofossils and other marine fauna from several horizons. Biswas negates the use of trace fossils as indicators of depositional environment7,8, but quotes unpublished study supporting use of trace fossils as environmental in-dicators. Again the term transitional en-vironment is vague. Detailed facies analysis of the Bhuj Formation3 is available, which Biswas seems to have ignored. Biswas tries to interpret the Bhuj For-mation as deposits of delta system with influence of tides and waves. A delta is built mostly by marine processes in a sea and hence is part of a marine depositional system where different coastal facies dominate. This has been already docu-mented3,7.

1. Biswas, S. K., Q. J. Geol. Min. Metall. Soc. India, 1977, 49, 1–52.

2. JaiKrishna, Singh, I. B., Howard, J. D. and Jafar, S. A., Nature, 1983, 305, 790–792.

3. Shukla, U. K. and Singh, I. B., J. Palaeon-tol. Soc. India, 1990, 35, 189–196.

4. Shukla, U. K. and Singh, I. B., Curr. Sci., 1993, 65, 171–174.

5. Waagen, W., Palaeontol. Indica, 1875, 9.1. 6. JaiKrishna, Newsl. Stratigr., 1991, 23,

141–150. 7. Singh, I. B. and Shukla, U. K., J. Palaeon-

tol. Soc. India, 1991, 36, 121–126. 8. Howard, J. D. and Singh, I. B., Palaeo-

geogr., Palaeoclimatol., Palaeoecol., 1985, 52, 99–122.

JYOTSANA RAI

Birbal Sahni Institute of Palaeobotany, Lucknow 226 007, India e-mail: jyotsana_rai@yahoo.com