age of the mfamosing limestone, calabar flank, south - ijens
TRANSCRIPT
International Journal of Basic & Applied Sciences IJBAS-IJENS Vol:10 No:05 8
107105-6464 IJBAS-IJENS © October 2010 IJENS I J E N S
Age of the Mfamosing Limestone, Calabar Flank,
South Eastern, Nigeria
*Essien, N. U. and Ufot, D. O.
Department of Geology, University of Calabar,
P.M.B. 1115. Calabar. Nigeria
*Corresponding author’s e - mail: [email protected]
Abstract-- Palynological analyses of outcrop samples and cores
from two (2) wells were used in the determination of the age of
the Mfamosing Limestone. Quantitative palynological analyses of
the shaly intercalations in outcrop sections and the shales
immediately overlying this limestone formation reveals the
presence of index Albian-Cenomanian palynomorphs such as
Classopollis jardinei, Ephedripites procerus, Ephedripites
striagatus, Elaterosporites protensus and Elaterosporites sp. The
palynological analyses points to a Mid Albian – Early
Cenomanian age for the Mfamosing Limestone.
Index Term-- Mfamosing Limestone, Age, Palynomorph,
Albian - Cenomanian.
I. INTRODUCTION
The actual age of the Mfamosing Limestone has been
a subject of discussion over the years by various workers
Reyment 1965, Dessauvagie 1968, Nair et al., 1982, Zaborski
1982, Ramanathan and Nair 1984, Akpan 1992. This research
is a contribution to this on-going debate using palynology. The
approaches used in this research include: detailed field
mapping, sampling of outcrops and cores and laboratory
analyses of these samples for the determination of the age of
the Mfamosing Limestone. Samples used for this research
were obtained from limestone outcrops and from two wells,
ODBH4/2 and ETBH3/2 located at Odukpani and Etankpini
villages in the study area respectively. The samples were
mainly the interbedded shale horizons within the limestone
unit in some outcrop sections and the shales immediately
overlying the limestone. These intercalated shales are
evidence of rhythmic cyclic deep marine incursions during the
pronounced Mid-Albian marine transgression in the South
Atlantic. These samples were subjected to palynological
investigation to identify the various age diagnostic forms
which is the basis for age determination for the carbonate
buildup.
The formation under study is the Mfamosing
Limestone (Petters,1982) near Calabar, South Eastern Nigeria.
This carbonate platform is located within the Calabar Flank
(Murat 1972) and represents the thickest carbonate body in
Nigeria (Reijers and Petters, 1987) (Fig. 1 and 2).It is about
50m thick at outcrop (type section) and 450m thick in the
subsurface on the Ituk high (Reijers and Petters,1987).
II. GEOLOGIC SETTING AND STRATIGRAPHY Geologically, Calabar Flank is unique in many respects; it is
that part of the southern Nigerian sedimentary basin that is
bounded by the Oban massif to the north and the Calabar
hinge line delineating the Niger Delta basin in the south (Fig.
2; Nyong 1995). It is also separated from the Ikpe platform to
the west by a NE-SW trending fault. In the east, it extends up
to the Cameroun volcanic ridge. It served as the gateway to
all marine transgression into the Benue Trough and is located
between two hydrocarbon provinces, the Tertiary Niger Delta
and the Cretaceous Douala basin in Cameroun (Reijers and
Petters, 1987).
Structurally, the Calabar Flank consists of basement horsts
and grabens that are aligned in a NW – SE direction like other
South Atlantic marginal basins in West Africa (Reijers and
Petters, 1987). The Calabar Flank shows striking stratigraphic
similarities with other coeval marginal basins of the South
Atlantic. They were all produced during the opening of the
South Atlantic Ocean and the first marine incursion in Middle
Albian accounted for the deposition of Mfamosing Limestone
particularly on the horst and relatively stable platform areas
and their Flanks (Fig.2).
Sedimentation started in the Calabar Flank with deposition of
fluvio-deltaic clastics of probably Aptian age on the
Precambrian crystalline basement complex, the Oban Massif
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Nkporo Shale
New Netim Marl
Ekenkpon Shale
Mfamosing Limestone(Area under study)
Awi Formation
Asu River Group
Basement Complex
Location of Towns
Fig.1. Geologic sketch map of south – eastern Nigeria showing Mfamosing Limestone of the Calabar Flank (Modified after Petters et al.,1995).
Index Map
NE
B
Niger Delta Volc
anic
s
SW
IkpePlatform
A
CALABARFLANK
Oban Massif
NEB
Nig
er
De
lta
C a mp a n o Ma a s t ri c h t i a n
? Aptian
Albian
Coniacian
Turonian
Cenomanian
SW
Ca
lab
ar
Hin
ge
Lin
e
Itu
k H
igh
Ika
ng
Tro
ug
h
Ob
an
Ma
ssif
A
ShaleSandstone Limestone
Basement Marls
Structural elements and conceptual subsurface distribution of Cretaceuos
sediments in the Calabar Flank
Fig. 2. Structural elements and conceptual subsurface distribution of Cretaceous sediments in the Calabar Flank ( After Nyong,1995).
(Fig. 1). These sediments belong to the Awi Formation
(Adeleye and Fayose, 1978). The earliest marine transgression
into the Calabar Flank occurred in the Mid-Albian times with
the deposition of platform carbonate of the Mfamosing
Limestone. This carbonate body was deposited in a variety of
depositional environment.
International Journal of Basic & Applied Sciences IJBAS-IJENS Vol:10 No:05 10
107105-6464 IJBAS-IJENS © October 2010 IJENS I J E N S
The Mfamosing Limestone is overlain by a thick
sequence of black to gray shale unit, the Ekenkpon Formation
(Petters et al., 1995). This formation is characterized by minor
intercalation of marls, calcareous mudstone and oyster beds.
This shale unit was deposited during the Late Cenomanian-
Turonian times.
The Ekenkpon Shales are overlain by a thick marl
unit, the New Netim Marl (Petters et al., 1995). This unit is
nodular and shaly at the base and is interbedded with thin
layer of Shales in up-section. Foraminiferal (Nyong, 1995)
and Coccolith evidence (Perch – Nielson and Petters, 1981)
suggest Early Conciacian age for this marl unit.
The New Netim Marl is unconformably overlain by a
carbonaceous dark gray Shales, the Nkporo Formation
(Reyment, 1965). This Shale unit was deposited during the
Late Campanian – Maastrichtian times. The Nkporo Shales
caps the Cretaceous sequence in the Calabar Flank.
The Nkporo Shales sequence is overlain by a pebbly
sandstone unit of the Tertiary Benin Formation.
III. PREVIOUS WORK
The age of the Mfamosing Limestone has been a subject
of discussion by several researchers. Various researchers have
ascribed different ages based on different criteria.
Reyment (1965) assigned a Cenomanian age to the rocks
which constitute the Odukpani Formation in which the
Mfamosing Limestone forms the basal unit. Dessauvagie
(1968) reported the occurrence of a foraminiferal species
Trocholina odukpaniensis from this limestone and proposed a
Late Albian age base on this. Nair et al., (1982), described the
limestone sequence to be barren of foraminifera suitable for
reliable age dating but deduced a Late Albian to Early
Cenomanian age based on ammonite biostratigraphic analyses.
They concluded that the limestone can not be younger than
Late Albian. (Ramanathan and Nair 1984) in correlating
Gboko Limestone in a quarry section with the Mfamosing
Limestone recorded the occurrence of forms such as
Anomalina plummerae, Gavelinella intermedia, Patellina
subcretacea, Ammobaculites coprolithiformis, Ammobaculites
fisheri and Ammobaculites irregulariformis. Based on these
species, they suggested an age ranging from Late Aptian to
Albian for the Gboko Limestone and correlated it to the
Mfamosing Limestone in the Calabar Flank. Akpan (1992)
recorded for the first time the Itierid gastropod, Peruviella
dolium in the basal sections of the Mfamosing Limestone and
on that basis, assigned a Mid – Albian age to this limestone
unit.
Forster (1978) and Forster and Scholtz (1979) presented
ammonite biostratigraphic evidence for a Late Albian age for
the top of the Mfamosing Limestone. Cenomanian age has
also been proposed based on ammonite evidence (Reyment,
1965).
An ammonite biostratigraphy by Zaborski (1982) revealed
Upper Albian - Lower Cenomanian ammonites, including well
known taxa such as Mariella m. ochleti, Puzosia cf
antanimangaensis, Pachydesmoceras cf., radaodyi,
Desmocers d., latidorsatum and Flickia quadrata, from the
base of the shale immediately overlying the Mfamosing
Limestone. Based on these he proposed an Albian age for the
subjacent Mfamosing Limestone. These, together with the
discovery of an actual Albian ammonite from the hard ground
at the top of the Mfamosing Limestone gave evidence for an
Albian age for the limestone unit.
IV. METHODOLOGY
Extensive field mapping of the Mfamosing
Limestone was carried out along its depositional strike a
distance of 163km. A total of thirty two (32) samples were
collected from outcrops and from two (2) wells, ODBH42
(Odukpani village) and ETBH32 (Etankpini village), located
in the study area (Fig. 3).
The shale units interbedded within the limestone were
subjected to palynomorphs preparation to free the pollen and
spores from enclosing matrix for picking and identification.
Age determination was achieved by the use of age diagnostic
taxa.
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V. RESULTS
The palynomorphs recovered from the shales immediately
overlying the Mfamosing Limestone and the shales
intercalating this limestone body were used for the
determination of age of the limestone formation.
VI. PALYNOMORPHS AND AGE
DETERMINATION
A total of thirty two (32) samples were analyzed for
palynomorph assemblages. These samples include twenty
outcrop samples and twelve cores from two wells (ODBH4/2
and ETBH3/2) in the study area.
The outcrops samples yielded bissacate pollen, and associated
elements like fungal spores and chitinous microforaminiferal
test linings (Fig. 4).
The summary of the different species of pollen and spores
recovered from the two wells are shown in Fig. 5 and 6.
Age interpretations were attempted with the use of
important index palynomorphs.
VII. DISCUSSION
The presence of Elaterosporites group and Triorites
africaensis Jardine and Magloire 1965, suggest an Albian –
Cenomanian age for the analysed samples.
These species have already been recorded in Nigeria by Jan D
Chene` 1978. Other important Albian index palynomorphs
recorded include Classopollis jardinei, Steevesipollenites
giganteus, Trifossapollenites polygonalis, Ephedripites
procerus, and Ephedripites striagatus.
FIG.16 P aly nom orp hs d is tribution of a s tud ied S ection . (M fam os ing v illage) in the s tud y area.
Shale Limestone
O
X
Present
Absent
MFA
MO
SIN
G
LIT
HO
LOG
IC
SE
CT
ION
FO
RM
AT
ION
TH
ICK
NE
SS
(m)
SA
MP
LE
NO
S.
0.02m
0.23m
0.02m
0.02m
0.07m
0.25m
0.18m
L1
L - Sh1 1
L2
L - Sh1 2
L3
L - Sh1 3
L4
L5
0.02mIN
DE
TE
RM
INA
TE
A
GE
EN
VIR
ON
MEN
T
MARINE X O
CH
ITIN
OU
S
MIC
RO
FO
RA
MIF
ER
AL
LIN
ING
BIS
SA
CA
TE
PO
LL
EN
L - Sh1 4
MARINE X X
MARINE X O
MARINE X O
Fig. 4. Palynomorph distribution in a studied section (Mfamosing village) in the study area.
International Journal of Basic & Applied Sciences IJBAS-IJENS Vol:10 No:05 13
107105-6464 IJBAS-IJENS © October 2010 IJENS I J E N S
Shale Limestone X
O
Present
AbsentSandstone
O
O
O
X
O
O
O
O
O
O
O
O
O
X
O
O
O
O
O
O
X
X
X
X
O
O
O
O
O
X
O
O
O
O
O
O
O
X X
O
O
O
O
X
X
X
O
O
O
O
O
O
X
X
X
X
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
A L B IA N -C E N O M A N IA N
NIL
NIL
4.59 - 10.45
10.45 - 17.15
17.15 - 25.35
31.30 - 35.46
35.46 4 . 0 - 1 8
42.75 - 51.35
25.35 - 31.30
DE
PT
H
(M)
LIT
HO
LO
GY
AG
E
Ep
he
dri
pite
s
pro
ce
rus
Mo
no
co
lpite
s
ma
rgin
atu
s
Lyco
po
diu
msp
ori
tes
sp
Cla
sso
po
llis
jard
ine
i
Le
iotr
ile
tes
ad
rie
nn
is
Lyg
od
ium
sp
ori
te
ad
rie
nn
o
Re
tritri
co
lpite
s
ojo
en
sis
Ep
he
dri
pite
s
sp
Ste
eve
sip
olle
nite
s
sp
Po
lyp
od
idite
s
sp
Ste
eve
sip
olle
nite
s
su
bti
slis
Ste
eve
sip
olle
nite
s
gig
an
teu
s
Tri
fossa
po
lle
nite
s
sp
Le
iotr
ile
tes
ad
rie
nn
is
Od
onto
ch
ina
sp
Ela
tero
sp
ori
tes
sp
Hystr
ich
oko
lpo
ma
sp
Mu
ltip
oro
po
lle
nite
s
po
lyg
on
alis
Cri
bro
pe
rid
inlu
m
sp
Chitin
ous m
icro
fora
min
ifera
lin
ing
Din
oflag
ella
te c
yst
O
O
O
O
O
O
O
O
X
O
O
O
O
X
X
X
O
X
X
X
X
O
O
O
X
X
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
NOT INVESTIGATED
MF
AM
OS
ING
FO
RM
AT
ION
SA
MP
LE
NO
S
A1
A2
A3
A4
A5
A6
EK
EN
KP
ON
GA
WI
A L B IA N -C E N O M A N IA N
A L B IA N -C E N O M A N IA N
A L B IA N -C E N O M A N IA N
A L B IA N -C E N O M A N IA N
Fig. 5. Palynomorphs distribution chart for well ODBH4/2 (Odukpani village) in the study area
International Journal of Basic & Applied Sciences IJBAS-IJENS Vol:10 No:05 14
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S ha le S a ndstone Lim e stone
X
O
P re se nt
A bse nt
INDETERMINATE
DE
PTH
(M
)
SA
MP
LE
NO
S
LIT
HO
LOG
Y
AG
E
O
X
O
O
O
O
O
O O
O
O
X O
O
O
X O
X
X O
X
O
O
O
X X
X
O
X
X
X
O O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
X
X O
O
X
X
X
O
O
X
X
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
X O
O
O
O
O
O
O
O
NOT INVESTIGATED
Ret
ritric
olpi
tes
ojo
ensi
s
Cla
ssop
ollis
ar
dine
Ltr
ilet
s a
drie
nnis
Ste
eves
ipol
leni
tes
gig
ante
s
Eph
edrip
ites
p
Ela
tero
spor
ites
p
Ela
tero
spor
ites
pro
tens
us
Ste
ees
ipol
leni
tes
p
Syn
celp
orite
s
p
Eph
edrip
ites
ro
ceus
Eph
edrip
ites
tr
iaga
tus
Gam
mat
rilet
es
lara
tus
Fun
gal
pore
ji
eio
e
u
s
s
vs
s pr
s c
s
Chi
tinou
s m
icro
fora
min
ifera
lini
ng
MFA
MO
SIN
GFO
RM
ATI
ON
D1 2.44 6.96 -
D2 6.96 - 11.77
1. -
D3 1 77 16.03
D4 16 0 21.35 . 3 -
D5 2 5 26.35 1.3 -
31.01 - 44.35
D6 26.35 - 31.01
-
EK
EN
KP
ON
GA
WI
A LB IA N-CENO M A NIA N
A LB IA N-CENO M A NIA N
A LB IA N-CENO M A NIA N
A LB IA N-CENO M A NIA N
A LB IA N-CENO M A NIA N
Fig. 6. Palynomorphs distribution chart for well ETBH3/2 (Etankpni village) in the study area
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FIG.7 Ranges of the key Sporomorph markers for the Early - Late Cretaceous in the Calabar flank from Well ODBH 4/2 (Odukpani village) and ETBH 3/2 (Etankpini village) in the study ar ea.
Ep
he
dri
pit
es
p
roce
rus
Cla
ss
op
oll
is
jard
ine
i
Ste
ev
es
ipo
llen
ites
g
iga
nte
us
Tri
fos
sa
po
llen
ites
sp
Ela
tero
sp
ori
tes
sp
Mu
ltip
oro
po
llen
ites
po
lyg
on
ali
s
Ly
co
po
diu
msp
ori
tes
sp
Mo
no
co
lpit
es
Ma
rgin
atu
s
Le
iotr
ilete
s a
dri
en
nis
Ly
go
diu
ms
po
rite
s a
dri
en
no
Re
trit
ric
olp
ites
ojo
en
sis
Ep
he
dri
pit
es
sp
Ste
ev
es
ipo
llen
ites
sp
Po
lyp
od
idit
es
sp
Ste
ev
es
ipo
llen
ites
su
bti
lis
Ste
ev
es
ipo
llen
ites
sp
Ep
he
dri
pit
es
str
iag
atu
s
Gam
ma
tril
ete
s c
lara
tus
Syn
ce
lpo
rite
s s
p
Hy
str
ich
ok
olp
om
a s
p
Od
on
toch
itin
a s
p
Cri
bro
pe
rid
inlu
m S
p
AG
E
SU
PE
RZ
ON
E
ZO
NE
13 Proteacidites dehani
11 Auriculiidites reticeilaris
10 Droseridites senonicus
9 Interval zone
8 Triorites africaensis
7 Elaterosporites - afropollis
12 C subprotatusrassitricolporites
6 Elateropollenites jardinei
5 Tricolpites - E. Tumulus
4 I. Crisopolensis - afropollis3 A. spinulosis - E. tumulus2 Densoisporites perinatus
1 Alisporites - D. etrusaus
Maastrichtian
Aptian
Barremian
Barre. / Neoc
Maast / Camp
Sant. / Coniac
Turonian
LATECENOMANIANMIDDLECENOMANIAN
CENOM. / ALBIAN
MIDDLE ALBIAN
EARLY ALBIAN
VI
V
IV
III
II
I
ME
SO
ZO
IC
LA
TE
CR
ET
AC
EO
US
EA
RLY
EP
OC
H
PE
RIO
D
ER
A
Fig. 7. Ranges of key sporomorphs markers for the Early – Late Cretaceous in the Calabar Flank
from well ODBH4/2 (Odukpani village) and ETBH3/2 (Etankpini village) in the study area.
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The above index palynomorphs association indicates a Mid
Albian – Early Cenomanian age, for the Mfamosing
Limestone.
In well ETBH3/2 in Etankpini village, cores analyzed revealed
the presence of Classopollis jardinei (85%) in 2.44m-6.96m
interval in association with other palynomorphs. At 6.96m-
11.77m interval, Steevesipollenites giganteus (6%) and
Elaterosporites sp (20%) are also found. Within 11.77m-
16.03m, Classopollis jardinei (50%), Elaterosporites sp
(20%), Elaterosporites protensus (40%) and Steevesipollenites
giganteus (10%) were recovered.
Between 16.03m-21.35m there was absence of Albian –
Cenomanian index palynomorphs except for the presence of
Ephedripites striagatus and fungal spore. Samples analyzed
between 21.35m-26.35m indicate the presence of chitinous
microforaminiferal test linings (Fig.6).
The above association in well ETBH3/2 indicates age ranging
from Mid Albian – Early Cenomanian.
Fig.7 shows the different palynomorph zones for the
Cretaceous and the ranges of different species from the
studied wells in the study area.
VIII. PALEOENVIRONMENT
Paleoenvironmental interpretation based on identified
palynomorphs in the light of their ecological preferences and
the relative proportions of palynomorphs groups, indicate that
the Albian – Cenomanian sediments were deposited in a
marginal marine environment with vegetation on wetlands,
under a relatively dry climate.
IX. CONCLUSION
Palynological analysis reveals the presence of diagnostic
Albian – Cenomanian (Lower Cretaceous) assemblages in the
Mfamosing Limestone. The presence of the following pollen
and spores: Classopollis jardinei, Ephedripites procerus,
Elaterosporites sp and Steevesipollenites sp confirms this age.
X. SYSTEMATIC PALYNOLOGY
Division SPORITES H. Potonie` 1893
CLASS A TRILETES (REINSCH 1881) POTONIE`
et KREMP 1954
Genus Lycopodium sporites
(THIERGART 1938) DELCOURT and SPRUMONT
1963
Occurrence: Sample A1, 4.59m-10.45m ODH4/2. Upper
Albian-
Lower Cenomanian of Nigeria.
Description: Single grain, radially symmetrical, anisopolar,
rounded in polar view. Laesuratrilete without costae, not
reaching the equatorial diameter. Surface reticulate.
Reticulum polygonal with muri, large at the base, finer at the
top.
Dimensions: Equatorial diameter: 45μ, length of the
laesura:12μ. Reticulum: muri: width 2μ at the base. 0.5μ at the
top, 2 to 3μ high.
Luminae: up to 5.5μ wide.
Distribution: in ODBH4/2, found only in the Upper Albian –
Lower Cenomanian interval.
Division 2 POLLENITES POTONIE` 1931
Class: POLYPLICATE IVERSEN and TROELS SMITH,
1950
Genus: Ephedripites BOLKHOVITINA 1953 ex
POTONIE`1953
Ephedripites sp.
Occurrence: Sample D2, D4, (ODBH3/2), A2, A4
(ODBH4/2)
Lower Albian – Upper Cenomanian of
Nigeria.
Description: Pollen grain of medium size, isopolar, radially
symmetrical, ellipsoidal in equatorial view, polyplicate. The
costae are flat and thick, the furrows are narrow and straight.
Dimensions: Size of the grain in equatorial view: 47 x 29μ.
Width of the costae: up to 6μ. Width of the furrows: 1μ.
Number of costae: 9-11.
Distribution: Found only in the Lower Albian – Upper
Cenomanian in ODBH4/2 and ETBH3/2.
Class: TRICOLPATAE IVERSEN and TROELS SMITH,
1950
Genus: Retitricolpites (VAN DER HAMMEN 1956)
VAN DER HAMMEN and WIMSTRA 1964
Retitricolpites ojoensis JAN DU CHENE
Occurrence: Sample D1, ETBH3/2, A2, ODBH4/2. Late
Cenomanian – Maastrichitian of Nigeria.
Description: Pollen grain of large size, sphaeroidal, isopolar,
radially symmetrical, tricolpate. The colpi are fine and long,
difficult to observe because of the coarse and irregular
reticulate sculpture.
Dimensions: Size of the grain in polar view: up to 83μ in
diameter. Length of the colpi: up to 30μ in polar view.
Reticulum: muri: up to 4.5μ high 2μ wide. Luminae: irregular.
Exine thickness: up to 2μ. Without muri.
Distribution: In well ODBH4/2 recorded at 10.45m-17.15m,
in ETBH3/2 recorded at 2.44m-6.96m.
Genus: Trifossapollenites ROUSE 1957
The genus Trifossapollenites first described in the upper
Cretaceous of Canada is common in the Aptian, Albian and
Cenomanian of Ivory Coast and Senegal. This genus had
already been recorded as a junior synomnym of
Triffossapollenites. Stratigraphically, it seems that the
Trifossapollenites group is recorded up to the top of the
Cenomanian in western Africa. Systematically, it may be
interesting to define some species which differ by thier size
and shape.
Trifossapollenites rousei JAN DU CHENE`
Occurrence: Core sample A4, 25.35m – 31.30m ODBH4/2.
Albian – Cenomanian of Mfamosing, Nigeria.
Description: Pollen grain of medium size, isopolar, radially
assymetrical, prolate (1.32), elliptical with flat extremities in
equatorial view. With three furrows. The principal furrow is
slightly longer than the two lateral onces. Exine psilate.
Dimensions: Size of the grain in equatorial view: 33 x 25µ.
Length of the furrow up to 21µ. Exine thickness: up to 2µ.
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Distribution: Rare. Found only in the Albian – Cenomanian.
REFERENCES [1] Adeleye, D. R. and E. A. Fayose, 1978, Stratigraphy of the type
section of Awi Formation, Odukpani Area, South-Eastern Nigeria,
Nigeria Journal of Mining Geology.15 (1) 35-37. [2] Akpan, E. B. (1992). Peruviella dolium (Roemer) and the age of
the Mfamosing Limestone, S.E. Nigeria. Nigerian Journal of
Mining Geology. 51(28), 191-196. [3] Dessauvagie, T. F. J. (1968). Cenomanian Trocholinas from
Nigeria. Micropaleontology. 14(1), 64-72.
[4] Forster, R. (1978). Evidence for an open sea way between Northern and Southern proto-Atlantic in Albian times. Nature.
Vol. 272 pp158-159.
[5] Forster, R. and Scholz, G. (1979). Salaziceras nigerianum I.sp. from Southern Atlantic in late Albian times. Neues Jb. Geology,
Paleontology and Mining. (2) 2,109-119.
[6] Jan Du Chene, R. De Klasz, I. and Archobong, E. E. (1978) Biostartigraphic study of the borehole Ojo – 1, SW Nigeria, with
special emphasis on the Creataceous microflora. Review of
Micropaleontology. 21 (3) 123 – 139. [7] Jardine S. and Magloire L. (1965). Palynologie et Stratigraphie du
Cre`tace` des basins du Senegal et de Cote d`Ivore. Memoirs de
Bureau du Recerche Geologie et Minere. (32) 1, 187 – 245. [8] Murat, R. (1972). Stratigraphy and paleogeography of the
Cretaceous and lower Tertiary in Southern Nigeria. In T.T.J.
Dessauvagie and A. J Whiteman (Eds.), African Geology. University Press, Ibadan, Nigeria. 251 – 226.
[9] Nair, K. M., R. M. Ramanathan and E. E. Ukpong (1982).
Sedimentology and stratigraphy of Cretaceous carbonates and associated rocks of Calabar Flank, Nigeria. Nigerian Journal of
Mining Geology. (18) 1, 120-129.
[10] Nyong, E. E. (1995). Geological Excursion Guide book to Calabar Flank and Oban Massif. In the 31st Annual conference of the
Nigerian Mining and Geosciences Society, Calabar, March 12 -16.
[11] Perch – Nielson, K. and S. W. Petters, (1981). Cretaceous and Eocene Microfossil ages, from the Southern Benue Trough,
Nigeria. Paleontographica (125) 2 102-120. Petters, S. W. (1982).
Central West African Cretaceous-ertiary benthic foraminifera and stratigraphy. Paleontographica (179)1-104.
[12] Petters, S. W. and E. E. Nyong, E. B. Akpan and N. U. Essien
(1995): Lithostratigraphic revision for the Calabar Flank, S. E. Nigeria, In Proceedings of the 31st Annivesary conference of
Nigeria Mining and Geosciences Society, Calabar.
[13] Ramanathan, R. M. and Nair, K.M. (1984) Lower Cretaceous foraminifera from Gboko Limestone, Eastern Nigeria. Nigeria
Journal of Geology. (21) 12, 41 – 48.
[14] Reijers, T.J.A and S.W. Petters, (1987). Depositional environment and diagenesis of Albian carbonates in Calabar Flank, S. E.
Nigeria: Journal of Petroleum Geology. (10), 283-294.
[15] Reyment, R. A.,(1965). Aspects of the Geology of Nigeria, Ibadan University. Press, Ibadan, 445.
[16] Zaborski, P. M. P., (1982). Campanian and Maastrichtian Sphenodiscid ammonites from Southern Nigeria. Bulletin of British
Museum and Natural History. Geological Service. 36(4), 302-332.
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APPENDIX: I PLATE 1
2 A
C D
E
A.Multiporopollenites sp (ODBH4/2,25.35m-31.30m),B. Steevesipollenites giganteus (ODBH4/2,17.15m-25.35m, ODBH3/2, 6.96m-11.77m,11.77m-16.03m) C,D,E. Elaterosporites sp,(ODBH4/2,10.17m-17.15m,25.35m-31.30m).X100.F.Monocolpites
marrginatus,ODBH3/2,4.59m-10.45M g.Classopollis jardinel,(ODBH3/2,4.59m-10.45m,17.15m-25.35m,31.30m-35.46m H. . Ephedripites
sp(ODBH3/2, 10.17m-17.15m,25.35m-31.30m. I. .Elaterosporites sp, (ODBH4/2,10.17m-17.15m,ODBH3/2, 6.96-11.77m,11.77m-16.03m
B
F
G
H
I
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107105-6464 IJBAS-IJENS © October 2010 IJENS I J E N S
PLATE 2
A,B Foram lining,(ODBH4/2 17.15m-31.30m ,ODBH3/2 21.35m-31.01m,L1-Sh1,L1-Sh2,L1-Sh3). X100. C.Dinocyst indeterminate,(ODBH4/2
17.15m-31.30m.). X 100.D. Ephedripites procerus,(ODBH4/2 4.59m-10.45m,25.35m-31.30m,ODBH3/2 11.77m-16.03m). X 100. E. Cretacaeaporites
polygonalis, (ODBH4/2 4.59m-10.45m). X 100. F. Steevesipollenites sp.(ODBH3/2 16.03m-21.35m,ODBH4/2 10.17m-17.15m,17.15m-25.35m).X 100
G. .Ephedripites procerus. X 100.
A
C
E F
B
D
G