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Journal of Asian Earth Sciences 100 (2015) 31–59

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Journal of Asian Earth Sciences

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Review

Ophiolites of Iran: Keys to understanding the tectonic evolution of SWAsia: (II) Mesozoic ophiolites

http://dx.doi.org/10.1016/j.jseaes.2014.12.0161367-9120/� 2015 Elsevier Ltd. All rights reserved.

⇑ Corresponding author.E-mail address: [email protected] (H.S. Moghadam).

Hadi Shafaii Moghadam a,⇑, Robert J. Stern b

a School of Earth Sciences, Damghan University, Damghan, Iranb Geosciences Dept., University of Texas at Dallas, Richardson, TX 75083-0688, USA

a r t i c l e i n f o

Article history:Received 29 May 2014Received in revised form 8 December 2014Accepted 16 December 2014Available online 13 January 2015

Keywords:OphioliteNeotethysCimmeriaSupra-subduction zoneMORBIran

a b s t r a c t

Iran is a mosaic of continental terranes of Cadomian (520–600 Ma) age, stitched together along suturesdecorated by Paleozoic and Mesozoic ophiolites. Here we present the current understanding of the Meso-zoic (and rare Cenozoic) ophiolites of Iran for the international geoscientific audience. We summarizefield, chemical and geochronological data from the literature and our own unpublished data. Mesozoicophiolites of Iran are mostly Cretaceous in age and are related to the Neotethys and associated backarcbasins on the S flank of Eurasia. These ophiolites can be subdivided into five belts: 1. Late CretaceousZagros outer belt ophiolites (ZOB) along the Main Zagros Thrust including Late Cretaceous–Early Paleo-cene Maku–Khoy–Salmas ophiolites in NW Iran as well as Kermanshah–Kurdistan, Neyriz and Esfanda-gheh (Haji Abad) ophiolites, also Late Cretaceous–Eocene ophiolites along the Iraq–Iran border; 2. LateCretaceous Zagros inner belt ophiolites (ZIB) including Nain, Dehshir, Shahr-e-Babak and Balvard–Baftophiolites along the southern periphery of the Central Iranian block and bending north into it; 3. Late Cre-taceous–Early Paleocene Sabzevar–Torbat-e-Heydarieh ophiolites of NE Iran; 4. Early to Late CretaceousBirjand–Nehbandan–Tchehel–Kureh ophiolites in eastern Iran between the Lut and Afghan blocks; and 5.Late Jurassic–Cretaceous Makran ophiolites of SE Iran including Kahnuj ophiolites. Most Mesozoic ophi-olites of Iran show supra-subduction zone (SSZ) geochemical signatures, indicating that SW Asia was asite of plate convergence during Late Mesozoic time, but also include a significant proportion showingocean-island basalt affinities, perhaps indicating the involvement of subcontinental lithospheric mantle.

� 2015 Elsevier Ltd. All rights reserved.

Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322. Geologic background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323. Field and structural characteristics of Iranian Mesozoic ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

3.1. Zagros outer belt ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.1.1. Khoy–Maku ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333.1.2. Late Cretaceous Iraqi–Iranian (Kurdistan) Zagros ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333.1.3. Eocene Hasanbag (Kurdistan)–Kermanshah ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353.1.4. Mesozoic Kermanshah ophiolite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353.1.5. Neyriz ophiolite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363.1.6. Haji Abad (Esfandagheh) ophiolite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.2. Zagros inner belt ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.2.1. Nain ophiolite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393.2.2. Dehshir ophiolite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393.2.3. Shahr-e-Babak ophiolite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403.2.4. Balvard–Baft ophiolite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
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32 H.S. Moghadam, R.J. Stern / Journal of Asian Earth Sciences 100 (2015) 31–59

3.3. Sabzevar–Torbat-e-Heydarieh ophiolitic belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3.3.1. Sabzevar ophiolite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413.3.2. Oryan–Bardaskan ophiolite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413.3.3. Torbat-e-Heydarieh ophiolite. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.4. Birjand–Nehbandan (Eastern Iranian) ophiolitic belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423.5. Makran ophiolites (SE Iran) including Kahnuj ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

3.5.1. Makran ophiolites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453.5.2. Kahnuj ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

4. Age constraints of Iranian ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.1. Zagros outer belt ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 474.2. Zagros inner belt ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 474.3. Sabzevar–Torbat-e-Heydarieh ophiolitic belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 474.4. Birjand–Nehbandan (Eastern Iranian) ophiolitic belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484.5. Makran ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5. Summary of compositional variations in Iranian Mesozoic ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5.1. Khoy–Maku and Zagros outer belt ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495.2. Zagros inner belt ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495.3. Sabzevar–Torbat-e-Heydarieh ophiolitic belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495.4. Birjand–Nehbandan (Eastern Iranian) ophiolitic belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505.5. Makran ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
6. Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
6.1. Comparison with other Mesozoic Tethyan ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
6.1.1. Comparison with Jurassic ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516.1.2. Comparison with Late Cretaceous ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516.1.3. Importance of Eocene ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

6.2. Petrological diversity of Iranian Mesozoic ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
6.2.1. Passive continental margin-type ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536.2.2. MORB-type ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536.2.3. Plume-type ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536.2.4. Supra-subduction zone-type ophiolites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536.2.5. Volcanic arc-type ophiolites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536.2.6. Accretionary prism-type ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
6.3. Tectonic evolution of Iranian Mesozoic ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
6.3.1. Zagros ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536.3.2. Khoy–Maku ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 556.3.3. Sabzevar–Torbat-e-Heydarieh ophiolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 556.3.4. Birjand–Nehbandan ophiolites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 556.3.5. Makran ophiolites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
7. Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

1. Introduction

Late Paleozoic–Early Mesozoic time was a period of continentalrifting, oceanic crust formation and accretion across Iran and otherCimmerian blocks including Afghanistan and Turkey, Lhasa andKarakoram. This is when the Paleotethys Ocean was consumedbeneath the southern margin of Eurasia and when Neotethys beganto open along the northern margin of Gondwana (ShafaiiMoghadam et al., 2014).

Neotethyan ophiolites define a �7000 km long belt acrosssouthern Eurasia and can be divided into two groups (Fig. 1;Abbate et al., 1980): (1) Jurassic ophiolites in the west (e.g., Dina-rides and Ligurian ophiolites) with MORB geochemical signatureand (2) mostly Cretaceous ophiolites in the east, which typicallyshow SSZ geochemical signatures. Southwest Asia is littered withophiolitic relicts of Neotethyan oceanic lithosphere, which delin-eate sutures between continental blocks rifted from Gondwana,including Arabia and India as well as the Cimmerian blocks of Ana-tolia, Iran, and Afghanistan. Most Neotethyan ophiolites in Cyprus,Turkey, Iran, Pakistan, Afghanistan, Oman and in the Tibetean Pla-teau have Late Cretaceous ages but some are older (e.g., ophiolitesin Caucasus and Iranian Makran) (Fig. 1). Iranian Neotethyan ophi-olites are an important part of the 3000 km long ophiolite-richzone that extends from Troodos (Cyprus) through Turkeyeastwards as far as Semail (Oman). These ophiolites have been

reviewed by multiple authors (e.g., Knipper et al., 1986; Mooreset al., 2000; Robertson, 2002; Dilek and Furnes, 2009) but a modernreview of Iran Mesozoic ophiolites is lacking.

In this paper, we review modern understanding of Mesozoicophiolites of Iran for the international geoscientific audience. Wehave learned a lot since the last review of Iranian ophiolites byDelaloye and Desmons (1980), a third of a century ago. This review– which should be regarded as a progress report – complementsour recent review of Paleozoic ophiolites of Iran (ShafaiiMoghadam and Stern, 2014). We incorporate our own resultsand field observations plus data from the literature. We use thetimescale of Walker et al. (2012) to relate biostratigraphic agesto radiometric ages. Below, we first outline the major features ofIranian basement geology (Section 2), then we focus on 6 greatbelts of Iran Mesozoic ophiolites, first summarizing their fieldrelations (Section 3), then age constraints (Section 4), and finallytheir petrology and geochemistry (Section 5) before brieflydiscussing the broader significance of Iran Mesozoic ophiolites(Section 6).

2. Geologic background

An outline of the main tectonic zones of Iran was given byShafaii Moghadam and Stern (2014) and here we present an abbre-

H.S. Moghadam, R.J. Stern / Journal of Asian Earth Sciences 100 (2015) 31–59 33

viated summary. Iran can be divided into 9 major tectonic zones(Fig. 2), from N to S including: (1) Kopet-Dagh zone in NE Iran;(2) The southern Caspian Sea basin; (3) Alborz zone in N-NW Iran;(4) The Central Iranian block or Cimmeria, consisting of threemajor old continental blocks (from E to W): Lut, Tabas, and Yazd,separated by major faults (e.g., Alavi, 1991) and similar crust tothe NW that is mostly buried beneath Cenozoic deposits; (5) East-ern Iranian suture zone; (6) Urumieh-Dokhtar magmatic belt, (7)The Zagros Fold-Thrust Belt (ZFTB), (8) Sanandaj–Sirjan zone(SNSZ), and (9) Makran.

Older continental fragments of Iran, including Alborz, TabasCentral Iran and Lut blocks contain crust as old as Ediacaran–Cam-brian, also known as Cadomian (Fig. 2). Iranian ophiolites can bedivided into Paleozoic ophiolites (Paleotethys remnants) andMesozoic and minor Paleogene ophiolites (Neotethys remnants)(Fig. 2). Paleozoic ophiolites are found in northern Iran, definingthe boundaries between the Turan (Eurasia) block and Cimmeria(Central Iranian and Alborz blocks) where Paleotethys was con-sumed by subduction beneath southern Eurasia (Alavi, 1991;Shafaii Moghadam and Stern, 2014).

Mesozoic and Paleogene ophiolites across Iran can be subdi-vided by age and geography into 5 belts (Fig. 2), as discussed in fol-lowing sections: (a) Late Cretaceous Zagros outer belt ophiolites(ZOB) along the Main Zagros Thrust including Late Cretaceous–Early Paleocene Maku–Khoy–Salmas ophiolites (Khoy–Maku beltin Fig. 2) in NW Iran as well as Kermanshah–Kurdistan, Neyrizand Esfandagheh (Haji Abad) ophiolites, also Late Cretaceous–Eocene ophiolites along the Iraq–Iran border; (b) Late CretaceousZagros inner belt ophiolites (ZIB) including Nain, Dehshir, Shahr-e-Babak and Balvard–Baft ophiolites along the southern peripheryof the Central Iranian block and bending north into it (Fig. 2); (c)Late Cretaceous–Early Paleocene Sabzevar–Torbat-e-Heydariehophiolites (Sabzevar–Torat belt in Fig. 2) of NE Iran; (d) Early toLate Cretaceous Birjand–Nehbandan–Tchehel–Kureh ophiolites(Birjand–Nehbanden belt in Fig. 2) in eastern Iran between theLut and Afghan blocks; and (e) Late Jurassic–Cretaceous Makranophiolites of SE Iran including Kahnuj ophiolites. Some of thesemay have originated as conterminous basins or forearcs, for exam-ple the Zagros belts with Makran; inner Zagros belt and Sabzevar–Torbat; Sabzevar–Torbat with Birjand–Nehbandan; and Makranwith Birjand–Nehbandan, but more work will be needed to addresssuch questions. Field relationships, age and geochemical data foreach ophiolitic belt are summarized in Tables 1 and 2. Even thoughthere are some Paleogene ophiolites, in the following all are calledMesozoic ophiolites for brevity.

3. Field and structural characteristics of Iranian Mesozoicophiolites

Below we describe the field and structural characteristics of the5 belts of Mesozoic ophiolites in Iran.

3.1. Zagros outer belt ophiolites

Zagros outer belt ophiolites (ZOB) is by far the longest of the fivebelts, stretching 1200 km from NW to SE Iran. This belt includesfive main occurences, from NW to SE: Khoy–Maku ophiolites,Iraqi–Iranian Zagros ophiolites (Kurdistan ophiolites), Kerman-shah, Neyriz and Haji Abad (Fig. 2). These slices are separated bythe Main Zagros Thrust (MZT) from the Zagros Fold-Thrust Beltto the SW, except the Khoy–Maku ophiolites of NW Iran. A sum-mary of Zagros ophiolites was recently provided by ShafaiiMoghadam and Stern (2011). We briefly discuss these ophiolitesbelow.

3.1.1. Khoy–Maku ophiolitesInformation about Khoy–Maku in NW Iran (Figs. 3 and 4) is

summarized in Table 1. The Khoy ophiolite was described byHassanipak and Ghazi (2000), Ghazi et al. (2003), Khalatbari-Jafari et al. (2003, 2004, 2006), and Azizi et al. (2005, 2011).Hassanipak and Ghazi (2000) concluded that the Khoy ophioliteis equivalent to the Inner Zagros Ophiolite Belt and formed by clos-ing the northwestern branch of a narrow Mesozoic seaway whichsurrounded the Central Iranian microcontinent. Khalatbari-Jafariet al. (2003, 2004) infered five main geological units from NE toSW in the Khoy region including (Fig. 4): (1) the SW continentalmargin of the Central Iranian block, (2) the eastern metamorphicunit including a Cadomian meta-ophiolitic complex, (3) thesupra-ophiolitic turbidites and volcano-sedimentary zone, (4) theunmetamorphosed Late Cretaceous Khoy ophiolite, and (5) thewestern metamorphic unit. The southern margin of the Central Ira-nian block is composed mainly of Neoproterozoic igneous andmetamorphic rocks overlain by Cambrian sedimentary rocks,which are disconformably overlain by Permian sediments. Theseolder sequences are tectonically overlain by Jurassic–Early Creta-ceous sediments. These unconformities are reliable indicators oftectonic movements.

The eastern metamorphic unit contains four main sub-units(Khalatbari-Jafari et al., 2003, 2004) consisting of micaschist,amphibolite (MORB to SSZ geochemical affinities), metavolcanicrocks, and gneissic rocks. The supra-ophiolitic volcano-sedimen-tary unit includes turbidites and coarse-grained breccias at thebase grading up into volcanic breccias and pillow lavas intercalatedwith pelagic sediments (Fig. 5). The younger, unmetamorphosedKhoy ophiolite complex is composed of mantle peridotite, layeredgabbro, diabasic dike swarm and a huge pile of phyric to aphyricpillowed to massive basalts (Fig. 5).

The western metamorphic unit consists of low-grade metamor-phic rocks of unknown origin and age. This unit may represent aneastern extension of the Permian and older Puturge–Bitlis meta-morphic rocks of eastern Turkey (Khalatbari-Jafari et al., 2003).

The Maku ophiolite is the NW continuation of the Khoy ophio-lite (Fig. 4). Cadomian metamorphic rocks outcrop NE and SE of theMaku ophiolite. Ankaramitic pillow lavas and basaltic to daciticcalc-alkaline lavas are common in the ophiolite near Siah-Chesh-meh (Figs. 4 and 5). Maku ophiolite pillow lavas are overlain byLate Cretaceous pelagic sediments and then turbiditic sedimentsof Late Cretaceous–Early Paleocene age. Thick pelagic limestonelayers are stratigraphically interleaved with pillow lavas(Fig. 6A), showing that volcanic and non-volcanic episodes alter-nated during basin evolution. Basaltic calc-alkaline/OIB-type sillsand dikes crosscut the overlying turbidites.

3.1.2. Late Cretaceous Iraqi–Iranian (Kurdistan) Zagros ophiolitesThe Zagros Orogen along the Iran–Iraq border is marked by

ophiolite massifs distributed along the MZT near Mawat, Hasanbag(Iraq) and Kurdistan (Iran). These ophiolites define a belt from Ker-manshah along the Iran–Iraq border and then into Turkey (Fig. 3).This ophiolite belt is not well studied but what we know about it issummarized in Table 1. The ophiolite belt is thought to link LateCretaceous Zagros and Khoy–Maku ophiolites. The ophiolites inIraq are juxtaposed with Balambo Cretaceous carbonate platformand deep-water radiolarite Qulqula Group rocks (Triassic–Creta-ceous). Suturing was followed by deposition of the Tanjero flyschin Maastrichtian time. Late Cretaceous Iraqi ophiolites (with SSZsignature) are associated with the Albian–Cenomanian HassanbagArc complex (Ali et al., 2012).

The Hassanbag Late Cretaceous igneous complex (Fig. 3) con-sists predominantly of calc-alkaline basaltic andesites to andesitesintruded by microgabbro and diorite dikes (Ali et al., 2012). Aliet al. (2012) considered that subduction of Neotethys seafloor

Table 1Summary of Iranian Mesozoic inner and outer Zagros ophiolitic belt characteristics.

Ophiolite, size Size Mantle lithology Crustallithology

Crust/mantleratio

Radiometricages

Type ofoverlyingsediments

Age ofsediments

Lavageochemistry

Temporalchangesof lavas

Cpx TiO2

in lavas(wt.%)

Mafic/felsiclavas

Cr# spinel Associatedmetamorphicrocks

Crustalsequencethickness

Ophioliteclassification

Proposedtectonicsetting

References

Khoy-Maku ophiolites 4000 km2 Mantlelherzolite,harzburgite,with minorchromitite

Gabbro, pillowto massivelavas, coldbreccia,pyroclasticrocks

4/1 73–101 K–Aron gabbro-plagioclase

Pelagiclimestones,radiolarites,turbiditesandpyroclasticrocks

LateCretaceous toEarlyPaleocene

OIB, E- MORBwith rare N-MORB, IATand calc-alkaline

MORB toSSZ-typelavas

Low ingabbrosbut highin E-MORB-OIB lavas

Mafic>>felsic �0.2 (lowCr#) and�0.3–0.6(high Cr#)

Micaschist,phyllite,amphibolite,gneiss

>5000 m MORB-type(with traceof temporalplume-type)to earlystage ofinfant arc

Mid-oceanicridge, Back-arc basin

This study,Khalatbari-Jafari et al.(2003, 2004),Monsef et al.(2010) andRezai et al.(2010)

Iraqi-Iranian Kurdistanophiolites �250 kmalong the MZT

1000 km2 Serpentinizedharzburgite,dunite,chromitite, (LateCretaceous SSZtype)

Ultramaficcumulates,gabbros–diorites, dikecomplex,pillow lava

2/1 106–92 Ma(Ar-Ar)

Pelagiclimestones-radiolarites

LateCretaceous

MORB andSSZ type-lavas &gabbros

? – Maficlavas>felsiclavas

0.5–0.8;�0.4–0.8in Penjwin

Sanandaj-Sirjanmetamorphicrocks

1000–1200 m

SSZ-type LateCretaceousSSZ type

Ali et al. (2012),Aswad et al.(2011), Allahy-ari et al. (2014),Saccani et al.(2014) andRahimzadeh(unpublisheddata)

Eocene ophiolite Cumulatelherzolite,gabbro, pillowlava, dike(Eocenevolcanic arcophiolite)

– �37–42 Ma Silicic ooze,radiolarites

– E-MORB to P-MORB-lavas<SSZ-type lavas

E-& P-MORBsareyoungerthan SSZlavas

0.8–1.3ingabbros

– �0.5–0.7inultramaficcumulates

Turbiditicphyllites (SSNZ)

>2000 m Intra-oceanicvolcanic arc-type

Eoceneintra-oceanic arcophiolite

Kermanshah ophiolite �2400 km2 Fertile lherzolite(Triassic–Jurassic passivemarginophiolite)

Flaser gabbros,meta-ultramaficrocks, pillowlava, dike

2/1 222 Ma (withxenocrysticzircons at 833& even older)

BisotunlimestonesandKermanshahradiolarites

Triassic–Cretaceous

OIB, E-, P-and N-MORB

– 0.36–1.47 ingabbros;0.85–2.44 inlavas

– 0.2–0.3 Metagabbros-metaultramaficrocks

– Passivemargin-type

LatePermian–Triassiccontinentalrifting

This study,Delaloye andDesmons(1980), Saccaniet al. (2013) andWhitechurchet al. (2014)

Harzburgite-dunite (LateCretaceous SSZtype)

Pillow-massivelava, gabbro,dike

3/1 86 Ma (K-Ar);98 Ma (U–Pb)

Pelagiclimestones,radiolarites,turbidites

Turonian-Maastrichtian

IAT and calc-alkaline,BABB

IAT tocalc-alkaline

– Maficlavas>felsicones

0.4–0.5 Sanandaj-Sirjanmetamorphicrocks

>2000 m SSZ-related Infant arc This study,ShafaiiMoghadam andStern (2011)

Neyriz ophiolite �1500 km2 Impregnatedperidotite,dunite,chromitites,pyroxenitic tobasaltic dikes

Mafic to felsicdikes insheeted dikecomplex,pillow lavas

1/3 92–93,gabbro, 86–93,plagiogranite(Ar-Ar)

Pelagiclimestoneandradiolarite

Cenomanian-Turonian toearlySantonian

FAB,boninite, IAT

Fore-arc-type lavastoboninites

0.02–0.9ingabbrosanddikes

Mafic<felsicdikes insheeted dikecomplex

0.4–0.8 Amphibolite,skarn,rodingites

�>1000 m SSZ-type Infant arc Babaei et al.(2006), ShafaiiMoghadam andStern (2011)

Haji-Abad (Esfandagheh)ophiolites includingSikhoran

�2000 km2 Ultramafic–maficcumulate,isotropicgabbros, felsicplutons anddikes

? UpperTriassic–Cretaceous(K-Ar)

Nosediments

– No lava – – Sargaz-Abshurmetamorphicrocks

– Ophiolite-like complex(ultramafic–maficintrusion)

Supra-subductionzone

Ghasemi et al.(2002) (Sikho-ran complex)

Harzburgite,impregnatedperidotite,dunite, dike

Ultramaficcumulates,plagiogranites,volcanic rocks

1/4 – Pelagiclimestones,radiolarite

LateCretaceous,Cenomanian

E-MORB,calc-alkaline,IAT, boninite

MORB toboninite

0.2–0.3in SSZ-typelavas

Felsiclavas>maficlavas

0.2–0.7 Blueschist andamphibolite

�>2000 m SSZ-type Fore-arc,infant arc

ShafaiiMoghadamet al. (2012) andShafaiiMoghadam andStern (2011)

Nain ophiolite 600 km2 Harzburgite,lherzolite,dunite, gabbroiclenses,pyroxenitic todiabasic dikes

Sheeted dikecomplex,pillowed andmassive lavas,coarse-grainedto isotropicgabbros

1/3 103–101 MaU–Pb)

Pelagiclimestones,radiolariteswith minorpyroclasticrocks

Coniacian–Maastrichtian

IAT, boninite IAT toboninite

0.01–0.77

Maficrocks>felsicones

0.2–0.6 Amphibolite,garnetamphibolite,rodingite

�>2000 m SSZ-type Forearc orshort-livedbackarc

Rahmani et al.(2007),Mehdipouret al. (2010) andShafaiiMoghadam andStern (2011)

Dehshir ophiolite �150 km2 Harzburgite,plagioclaselherzolite,clinopyroxenite,gabbro lenses

Sheeted dikecomplex,massive topillowed lavas,isotropicgabbros,plagiogranite

2/1 101–99 MaU–Pb)

Pelagiclimestone,radiolarites

Turonian–Maastrichtian

IAT and calc-alkaline withminor MORBand boninite

MORB toIAT/boninite

0.03–0.7 (mafic<<felsicdikes) insheeted dikecomplex

0.2–0.8 Calc-schist,amphiboleschist andamphibolite

�400–500 m

SSZ-type Forearc orshort-livedbackarc

ShafaiiMoghadamet al. (2010)

34H

.S.Moghadam

,R.J.Stern

/Journalof

Asian

EarthSciences

100(2015)

31–59

Tabl

e1

(con

tinu

ed)

Oph

ioli

te,s

ize

Size

Man

tle

lith

olog

yC

rust

alli

thol

ogy

Cru

st/

man

tle

rati

o

Rad

iom

etri

cag

esTy

peof

over

lyin

gse

dim

ents

Age

ofse

dim

ents

Lava

geoc

hem

istr

yTe

mpo

ral

chan

ges

ofla

vas

Cpx

TiO

2

inla

vas

(wt.

%)

Mafi

c/fe

lsic

lava

sC

r#sp

inel

Ass

ocia

ted

met

amor

phic

rock

s

Cru

stal

sequ

ence

thic

knes

s

Oph

ioli

tecl

assi

fica

tion

Prop

osed

tect

onic

sett

ing

Ref

eren

ces

Shah

r-e-

Bab

akop

hio

lite

�50

0km

2H

arzb

urg

ite

wit

hdi

abas

icdi

kes

and

gabb

roin

tru

sion

s

Vol

can

icro

cks

wit

hpy

rocl

asti

ced

ifice

s

3/1

–Pe

lagi

cli

mes

ton

es,

pyro

clas

tic

rock

s

Con

iaci

an-

Maa

stri

chti

anIA

Tan

dca

lc-

alka

lin

e–

0.1–

1.4

Fels

ic>>

mafi

c�

0.4

Min

oram

phib

olit

e–

SSZ-

type

Fore

arc

orsh

ort-

live

dba

ckar

c

Shaf

aii

Mog

had

aman

dSt

ern

(201

1)

Bal

vard

-Baf

top

hio

lite

800

km2

Lher

zoli

te,

har

zbu

rgit

ew

ith

diab

asic

dike

san

dga

bbro

icpo

cket

s

Pill

owed

tom

assi

vela

vas,

basa

ltic

–an

desi

tic–

daci

tic

sill

sin

pyro

clas

tic

rock

s

1/3

94–7

2,ga

bbro

(K–

Ar)

;10

3.2

±2.

4U

–Pb)

Pela

gic

lim

esto

nes

,ra

diol

arit

e,py

rocl

asti

cro

cks

Turo

nia

n–

Maa

stri

chti

anIA

T,ca

lc-

alka

lin

ean

dbo

nin

ite

wit

hm

inoi

rN

-an

dE-

MO

RB

MO

RB

/IA

Tto

bon

init

e/ca

lc-

alka

lin

e

0.2–

0.9

Fels

ic>

mafi

c�

0.5–

0.9

Min

oram

phib

olit

e>2

300

mSS

Z-re

late

dFo

rear

cor

shor

t-li

ved

back

arc

Shaf

aii

Mog

had

aman

dSt

ern

(201

1)an

dSh

afai

iM

ogh

adam

etal

.(20

13)


toward the east and northeast during Early Cretaceous time wasresponsible for development of the Hasanbag ophiolite-arc com-plex (106–92 Ma). The Penjween ophiolite (Fig. 3) includes mantleharzburgites and dunites grading upward into ultramafic cumu-lates-layered (low-Ti) gabbros and diabasic sheeted dike complex(Ali et al., 2012). The Iranian Kurdistan ophiolites occur along theMZT, between the Avroman–Bisotun limestones and Sanandaj–Sir-jan metamorphic rocks/Eocene ophiolites and include depletedharzburgites and fragmented gabbros/lavas.

3.1.3. Eocene Hasanbag (Kurdistan)–Kermanshah ophiolitesRare Eocene ophiolites occur along the Iran–Iraq border, from

Kermanshah (Iran) to Hasanbag (Iraq; Table 1. These are theWalash–Kermanshah volcano-sedimentary unit in Fig. 3 and arerelated to intra-oceanic subduction within Neotethys, similar tovolcanic-arc type ophiolites (e.g., Dilek and Furnes, 2011, 2014).During intraoceanic subduction in Eocene and Oligocene time,the island-arc complex (or arc-type ophiolite) formed theEocene–Oligocene Walash–Naopurdan magmatic group whichsubsequently accreted to the Arabian margin (Ali et al., 2013). Asimilar Eocene ophiolite also occurs in Kermanshah and IranianKurdistan. The Iranian Kurdistan ophiolites crop out in a tectonicwindow within turbiditic phyllites of the Sanandaj–Sirjan zone(SSNZ) and include from bottom to top: (1) ultramafic cumulate,(3) a gabbroic–dioritic sequence with granitic dikes, (4) both P-to E-MORB-like pillowed and calc-alkaline lavas unit with micro-gabbroic dikes.

In the Kermanshah region, Paleocene-Eocene turbidites andEocene calc-alkaline pillow lavas stratigraphically cover the LateCretaceous ophiolite. Eocene pillow lavas differ from Late Creta-ceous pillows by being intercalated with green shale and sand-stone turbidites. Dike swarms, including early basaltic anddiabasic dikes and late dacitic–rhyolitic to microdioritic dikes (usu-ally <0.5 m, locally >1 m wide), are present near Kherran and Sar-takht villages and show Eocene U–Pb zircon ages (ShafaiiMoghadam et al., unpublished data), interpreted to have formedduring extension associated with intraoceanic magmatism.Whitechurch et al. (2013) suggested that the Eocene ophioliticrocks (pillow lavas, gabbros and dikes) were intruded into the LateCretaceous Kermanshah ophiolite close to the ocean–continenttransition. They considered this as an Eocene arc, constructed ina Paleocene back-arc basin along the Eurasian continental margin.

3.1.4. Mesozoic Kermanshah ophioliteThe Kermanshah ophiolite, despite being one of the largest of all

Iranian ophiolites (exposed over �2400 km2), has not been studiedin detail. Kermanshah ophiolites are complex and include rem-nants of Late Permian–Triassic continental rifting (passive marginophiolite of Dilek and Furnes, 2011), Late Cretaceous SSZ ophiolitesand a Paleocene–Eocene intra-oceanic subduction system (Eoceneophiolite). This ophiolite trends NW–SE and is distributed in tworegions separated by SNSZ metamorphic rocks: in the NW, nearKamyaran, and in the SE, between Harsin and Sahneh. The ophio-lites between Harsin and Sahneh are Triassic to Early Cretaceousremnants of continental rifting and subsequent oceanic accretionat a mid-oceanic ridge (Saccani et al., 2013). The ophiolite is bor-dered to the NE by SSNZ metamorphic rocks and to the SW bythe Bisotun limestone, a �3 km thick Late Triassic to Late Creta-ceous (Cenomanian) carbonate sequence, as well as by Triassic toCretaceous Kermanshah radiolarites and then by Zagros Fold-Thrust Belt (ZFTB) sedimentary rocks. The Kermanshah ophiolitewas thrust over the Bisotun limestone during Maastrichtian–Palae-ocene time, evidenced by ophiolitic clasts in the Maastrichtian–Palaeocene Amiran Conglomerate Formation of the ZFTB (Braud,1987).

Mediterranean Sea Troodos

Alps

ZagrebBudapest

Black Sea

PontidesAnkara

Taurides

Caucasus

Baghdad

ARABIA

CaspianSea

Tehran

Neyriz

Semail

Birjand

Sabzevar

Nain

RedSea

EURASIA

Persian Gulf

Bitlis-Zagros Suture Zone

Indian Ocean

INDIA

Samarkand

Delhi

Lhasa

Yarlung-Zangbo Suture Zone

Tarim

Basin

10 Eo

20 Eo

30 Eo

40 Eo 50 E

o60 E

o70 E

o80 E

o 90 Eo

100 Eo

30 No

20 No

40 No

Tethyan ophiolites

Tethyan Suture Zones

AFRICA

JJ

J

K

K

K

J

J

K

KK

Makran

?

Bela

Muslim Bagh

Kohistan

K

KKJ

J=Mostly Jurassic

K=Mostly Cretaceous

K

Ligurian

Haji-Abad

Fig. 1. Distribution of Tethyan ophiolitic rocks in Alpine–Himalayan orogenic belt (modified from Dilek and Flower, 2003).


We can subdivide the Kermanshah and neigboring Iraqi Zagrosophiolites (Ali et al., 2012, 2013) into three subgroups: (1) Triassicto Cretaceous oceanic lithosphere (passive margin ophiolite)including OIB-type and E- to N-MORB-type gabbros and metagabb-ros, dikes (and a fragmented sheeted dike complex) and lavas asso-ciated with fertile meta-lherzolites. This lithosphere may mark arifted continental margin developed during early Neotethys open-ing (Saccani et al., 2013). (2) Late Cretaceous oceanic lithospherecomposed of SSZ-type gabbros and cumulates (including trocto-lites) within mantle harzburgites, SSZ-harzburgites and IAT tocalc-alkaline lavas, representing early arc magmatism (ShafaiiMoghadam and Stern, 2011); and (3) Paleocene–Eocene ophioliteswith calc-alkaline to E-MORB and P-MORB-like pillow lavas, felsic–mafic dike swarms and plutonic rocks, denoting mature intraoce-anic arc magmatism (Azizi et al., 2011).

The Kermanshah Late Cretaceous ophiolite near Kamyaran com-prises mantle and crustal rock sequences. The crustal sequence(>3000 m thick) is characterized by well-developed pillow lavas.It is difficult to distiguish Late Cretaceous lavas (pillow and/or mas-sive-type) from Eocene ones in the field. We distinguished Globo-truncara bearing-Late Cretaceous pelagic limestones betweensome calc-alkaline pillow lavas that were previously thought tobe Eocene (Fig. 6B).

3.1.5. Neyriz ophioliteIn the Neyriz region there are three imbricated sheets, from bot-

tom (SW) to top (NE): Pichukan series, mélange units, and ophio-lite (Table 1; Fig. 2; Ricou et al., 1977). The Pichakun series is asequence of Late Triassic limestone, Middle Jurassic oolitic lime-stone and Lower–Middle Cretaceous conglomeratic limestone, rep-resenting Neo-Tethys pelagic sediments (analogous to the Bisotunlimestone and radiolarites of Kermanshah). The Pichakun series iswedged between two thrust sheets of sheared mélange (Pamic andAdib, 1982; Babaei et al., 2001). Above the Pichukan series, themélange (or passive margin ophiolite) consists of exotic blocks ofPermian–Triassic Megalodon-bearing limestone associated withradiolarites and alkaline (OIB-type) to tholeiitic pillow lavas(Arvin, 1982; Babaei et al., 2006). The upper mélange is tectonicallyoverlain by Late Cretaceous ophiolite slices, and both ophiolite andmélange thrust sheets are transported over Cenomanian–Turonianshallow water carbonates (Sarvak Formation; Alavi, 1994). Thecontact of the lower mélange with the underlying autochthonousSarvak Formation is marked by a mylonitic amphibolite sole(Babaei et al., 2005).

The Late Cretaceous Neyriz ophiolite is composed of mantle andcrustal units capped by Cenomanian–Turonian to Early Santonianpelagic anhydritic limestones of the Tarbour Formation. The ophi-olite was thrust over the Pichakun and mélange sheets in Turonianto Maastrichtian time (e.g., Alavi, 1994; Babaei et al., 2006), expos-ing and allowing erosion of the ophiolite and accumulation of suchclasts in Late Cretaceous–Paleocene conglomerates (Lanphere andPamic, 1983).

The mantle sequence contains depleted to impregnated harz-burgites, layered leucogabbro, olivine-bearing melanogabbro andpyroxenite cumulate sills and lenses (Fig. 6C) with screens of resid-ual dunite, podiform chromitite, pyroxenitic sills/dikes, pegmatitegabbros, gabbroic dikes/sills, isotropic melano- to leuco-gabbrosand diabasic–basaltic–andesitic dikes (Fig. 7A). The Neyriz ophio-lite crustal sequence is best represented by �700–900 m thickfaulted sheeted dike complex and pillowed to massive lavas asso-ciated with chert and Late Cretaceous pelagic limestone.

3.1.6. Haji Abad (Esfandagheh) ophioliteThe Late Cretaceous Haji Abad (Esfandagheh) ophiolites and

associated arc-related rocks in southern Iran cover �2000 km2

near the MZT fault (Fig. 2). The Haji Abad ophiolite is in tectoniccontact with high-pressure blueschists of the Sanandaj–Sirjan zone(SSNZ), dated as 85–95 Ma (Agard et al., 2006). These are productsof high P/T metamorphism in a Late Cretaceous subduction chan-nel, exhumed in Early Paleogene time (Shafaii Moghadam andStern, 2011). The ophiolitic units including mantle peridotitetogether with gabbroic/anorthositic dikes/sills are metamorphosedat the contact with SSNZ metamorphic units.

Two distinct mafic–ultramafic complexes exist in the Haji Abad/Esfandagheh region; the older Sikhoran complex in the north, withUpper Triassic–Cretaceous ages (Ghasemi et al., 2002; Ahmadipouret al., 2003), and the younger, Late Cretaceous Haji Abad ophiolitein the south near the MZT. The Sikhoran complex comprises, frombottom to top, cumulate dunite–harzburgite and stratiform-likechromitite, wehrlite and pyroxenite cumulates (Ghasemi et al.,2002). The cumulate sequence is overlain by crustal isotropic gab-bros. No volcanic rocks or sheeted dikes are associated with theSikoran complex, so this may be a layered mafic–ultramafic intru-sion, not an ophiolite. This interpretation is supported by theobservation that the Sikhoran complex contains late-stage truegranitic dikes and shows thermal metamorphism at its contact.This older complex shows faulted/intrusive contacts with marbleand amphibolites of the Sargaz–Abshur complex and is intrudedby Late Triassic–Early Jurassic isotropic gabbros (Ghasemi et al.,

Table 2Summary of Iranian Mesozoic ophiolites (Birjand–Nehbandan, Sabzevar and Makran) characteristics.

Ophiolite Size Mantlelithology

Crustallithology

Crust/mantleratio

Radiometricages

Type ofoverlyingsediments

Age ofsediments

Lavageochemistry

Temporalchanges oflavas

CpxTiO2 inlavas

Mafic/felsiclavas

Cr# spinel Associatedmetamorphicrocks

Crustalsequencethickness

Ophioliteclassification

Proposedtectonicsetting

References

Sabzevar ophiolites 1500–4500 km2 Harzburgite,lherzolite,dunite andchromititewith dike

Isotropicgabbro,cumulategabbro,sheeted dikecomplex,plagiogranite,pillow lava

2/5 106–107 Ma(metamorphicrocks), 78–100 Ma forplagiogranites

Pelagicsediments,turbidites,with minorpyroclasticrocks

LateCampanian toEarlyMaastrichtian

IAT, calc-alkaline andboninite withminor OIB

Intercalated? 0.2–0.5ingabbros

Mafic > felsic 0.1–0.85 Lawsonite-bearingblueschist,granulite,greenschistandamphibolite

>3000 m Volcanic-arctype

Above S-dippingsubductionzone,forearcwithmature arc

This study,Rossettiet al. (2010,2013)

Oryan-Bardaskanophiolite

�5000 km2 Harzburgite,lherzolitewithdiabasicdikes,chromitite

Ultramafic tomaficcumulate,pillow lava

3/1 – Pelagiclimestones

LateCretaceous

Boninite, IAT,calc-alkaline

? – Mafic > felsic – – ? Volcanic-arc-type

Above S-dippingsubductionzone,forearcwithmature arc

This study

Torbat-e-Heydariehophiolite

�3000 km2 Harzburgite,dunite andchromititewithdiabasicdikes andgabbroiclenses

Pillow lava 1/3 97–98 Ma U–Pb zircon)

Pelagicsediments

LateCretaceous

IAT, calc-alkaline withminor MORB,BABB?

? 0.1–0.2ingabbros

Mafic > felsic 0.1–0.6 Amphibolite,greenschist

>�1000 m SSZ-type Back-arcbasinbehind theSabzevararc?

This study

Birjand–Nehbandanophiolites

� > 500 kmlength � 100 kmwide

Harzburgite,dunite,chromititewithdiabasic–gabbroicdikes

Ultramafic tomaficcumulates,gabbro,plagiogranite,pillowed tomassive lavas

2/3 87–83 (Rb-Sr),86–89 U–Pb)onmetamorphicrocks; 107–113 gabbro

Pelagiclimestones,radiolarites,pyroclasticrocks andturbidites

Early to LateCretaceous

IAT, calc-alkalne andMORB withminor OIB

IntercalatedMORB andSSZ-typelavas?

0.05–1.1

Maficlavas > felsiclavas

0.2–0.5 inperidotites,�0.5 inpillow lavas

Blueschist andeclogite

>3000 m MORB to SSZ Supra-subductionzone

This study,Babazadehand DeWever(2004),Zarrinkoubet al.(2012),Brockeret al.(2013) andTirrul et al.(1983)

Makran ophiolite �200 ⁄ 300 km Harzburgite,dunite

Cumulateultramaficrocks,cumulategabbros,isotropicgabbros,plagiogranite,SDC, pillowlava

3/1 120 Ma(gabbro, K-Ar);145–111 U–Pb;trondhjemite)

Pelagicsediments,pyroclasticrocks andturbidites

Jurassic toEarlyPaleocene

Calc-alkaline,IAT, MORB

? – Maficlavas > felsiclavas

0.5–0.8 inultramaficcumulates

Blueschist,amphiboliteand Bajgan-Durkanmetamorphicrocks

? Accretionaryprism-type

Supra-subductionzone

McCall(1985),McCall(2002) andHunzikeret al.(2011)

Kahnuj ophiolite 600 km2 – Cumulate andisotropicgabbros, SDC,pillow lavas,trondhjemites

3/1 156 and136 Ma or144–139 Ma(gabbro); 124–146 (Ar-Ar)diorite

Pelagiclimestones

Aptian-Cenomanian

VAT andMORB,(BABB)

MORB toSSZ-type?

0.33–2.1

Maficlavas > felsiclavas

– Amphibolites;Bajgan-Durkanmetamorphiccomplex

? SSZ-type Back-arcbasin

Kananianet al.(2001),Ghazi et al.(2004) andArvin et al.(2001)

H.S.M

oghadam,R

.J.Stern/Journal

ofA

sianEarth

Sciences100

(2015)31–

5937

Lut Block

Sabzevar-Torbat-e-Heydarieh

Birjand-Nehbandan

belt

Makran belt

Zagros IB

Zagros OB

Khoy-Maku belt Paleozoic ophiolite belt

Yazd Block

Taba

s Bl

ock

ophiolite beltBinalud Mountains

Mesozoic ophiolites

Central Iranian block

Paleozoic ophiolites

Major faults

Lut-Tabas-Yazd consolidated blocks

Alborz continental block

Ediacaran-Cambrian (Cadomian) terranes

Late Cretaceous oph. belt

Early Cretaceous oph. belt

Late Jurassic-K. oph. belt

Paleozoic ophiolite belt

Caspian Sea

Persian Gulf Gulf of Oman

Kermanshah

Neyriz

Haji-Abad

Nain

Shahr-e-Babak

Baft

Fanuj-Maskutan

Iranshahr

Birjand

Mashhad

Khoy

Sabzevar

Sanandaj-Sirjan Zone

Zagros Fold-Thrust Belt

Tehran

Kahnuj

Rasht

Anarak

50°E 54° 58°

26°

30°

34°

N

200km

Dehshir 525-547 MaSaghand

Torud-Biarjmand522-566 Ma

NW -SSZ544-551 Ma Soursat

540 Ma

Takab548-568 Ma

544-599 MaZanjan

Lahijan551-572 Ma

578-596 MaMuteh

Khoy566-595 Ma

Jaz Muriandepression

Fig. 3Fig. 8

Fig. 9

Fig. 10

Balvard

Sangbast-Shandiz Fault

Fig. 2. Simplified geological map of Iran emphasizing the main ophiolitic belts (thick dashed lines) and places where Cadomian (�600–520 Ma) radiometric ages aredocumented (stars). Numbers show U–Pb zircon ages (the age of Soursat is from Jamshidi Badr et al., 2011; from Khoy is from Azizi et al., 2011; other ages are fromHassanzadeh et al., 2008).


2002). The contact between the older northern ophiolite (Sikhoran)and the younger Haji Abad ophiolite to the south is faulted. Thesemafic–ultramafic complexes are intruded by Late Triassic–EarlyJurassic isotropic gabbros and Cretaceous diabasic dikes(Ghasemi et al., 2002).

The Haji Abad ophiolite formed in Late Cretaceous time. Theophiolite displays a disrupted pseudostratigraphy comprising frombottom to top: depleted mantle tectonites (harzburgites, impreg-nated harzburgites), ultramafic cumulates (dunite, chromitite,lherzolite, pyroxenite and wehrlite), plagiogranite, and a volcanicsequence. The well-developed volcanic complex consists of pillowbasalts and massive mafic to felsic lavas and shows faulted con-tacts with other units, especially serpentinized peridotite. Lavaflows are overlain tectonically or stratigraphically by Late Creta-ceous (Cenomanian) pelagic limestone. The volcanic section con-sists of three types of pillow lavas that occur in different places,

so relationships and overall thickness are not clear. These include>2000 m thick boninites and �1000 m thick E-MORB-type pillowlavas (Shafaii Moghadam et al., 2012). Boninitic lavas are overlainby and interbedded with minor IAT lavas. There is also a thicksequence of calc-alkaline lavas but thickness is unclear becauseof faulting.

3.2. Zagros inner belt ophiolites

Most researchers consider ZIB ophiolites as ophiolitic mélangethat marks a Neo-Tethyan oceanic basin between the SNSZ andLut blocks (e.g., Berberian and King, 1981; Arvin and Robinson,1994; Arvin and Shokri, 1997; Glennie, 2000). Other researchersinfer that the marks a Campanian back-arc basin (e.g., Stampfliand Borel, 2002; Agard et al., 2006; Shafaii Moghadam et al.,2009; Mehdipour Ghazi et al., 2012), which was a narrow seaway

Khoy

Maku

Serow

Kermanshah Sahneh

HamadanKamyaran

border

Marivan

Sanandaj

Penjween

MawatBaneh

Sardasht

PiranshahrGalalah choman

Sanandaj-Sirjan ZoneZagros Fold-Thrust Belt

IRAQIRAN

50 Km

44˚0

0´

45˚0

0´

46˚0

0´

47˚0

0´

34˚00´

35˚00´

36˚00´

37˚00´

TURKEY

38˚00´

39˚00´

MZT

Naqadeh

Plio-Quaternary volcanic rocks

Paleozoic Metamorphic rocks

Qulqula-Kermanshah radiolaritesTriassic-Cretaceous

Avroman-Bisotun limestonesTriassic-Cretaceous

Late Cretaceous ophiolites

Naopurdan volcanosedimentary unitPaleogene

Walash-Kermanshah volcanosedi. unitPaleogene ophiolite

Khoy-Maku ophiolites

Kermanshah-Kurdistan ophiolites

Connecting pathway?Piranshahr-Serow ophiolites

Hassanbag

Fig. 3. Simplified map showing the distribution of the Khoy–Maku and Kermanshah ophiolites with emphasis on the Piranshahr–Serow ophiolites that seem to connect thesetwo belts (Modified after Ali et al., 2013).


with discontinuous oceanic crust (Shafaii Moghadam et al., 2009).The NE limit of ZIB is buried beneath younger deposits and maylink up with Sabzevar ophiolites in NE Iran (Fig. 2).

Below we discuss four large ZIB ophiolites: Nain, Dehshir,Shahr-e-Babak, and Balvard–Baft (Fig. 2).

3.2.1. Nain ophioliteThe Nain ophiolite (Table 1) is dominated by a mantle sequence

with isolated outliers of crustal rocks. The mantle sequence ismainly moderately depleted harzburgite with minor plagioclaselherzolite formed by impregnation. Pyroxenitic, gabbroic, gabbron-oritic and diabasic dikes and sills crosscut the Nain mantlesequence (Fig. 7B). The Nain ophiolite crustal sequence is

�2000 m thick and includes a sheeted dike complex and overlyinglavas (Fig. 7B). The sheeted dike complex contains mafic and felsicdikes associated with more depleted gabbronoritic dikes showingmutually intrusive contacts. Pillowed and massive lava flowsoverly the sheeted dike complex. Globotruncana-bearing Late Cre-taceous pelagic limestones overlie the pillow lavas and are foundas thin screens between pillows. Pelagic limestones are uncon-formably overlain by grey sandy Paleogene limestones with a basalconglomerate.

3.2.2. Dehshir ophioliteThe Dehshir ophiolite (Table 1) consists of excellent crust and

mantle exposures, most recently studied by Shafaii Moghadam

TURK

EY

^

^^^ ^ ^^^

^^ ^

^^^

^^^

^^^ ^

^

^

^

^^

^

^ ^

^

^^

^ ^ ^

^

^

^ ^^

^^

^^

^^

^

^

^^

^

^^

^

^

^

^^ ^

^

^

^

^

^

^

^

^

^^

^

^

^^

^

^

^^

. .

......

. .... .

...

.

^

^ ^

^

^

^

^^

^^ ^

^ ^^ ^ ^

^^

^ ^

^ ^^

. . . .. . ...

... .. . .. ..

. . .. . .. . . ... ... . . ..

KHOY

Firoraq

^^

^

^

^^

^ ^ ^ ^^

^^ ^

^^

^

^

^

^ ^

^

^

^ ^

^^

^ ^^

^

^^ ^

^^

^ ^

MAKU

Mazraeh

ShahBandalu

Dibak

Siah-Cheshmeh

Khan Gol

Zurabad

Geldgh

Galavans

Tudan Dizeh

20 Km

44˚15´ 44˚30´ 44˚45´

38˚30´

38˚45´

39˚00´

39˚15´

Metamorphic rocksPhyllite, schist, gneiss

550 Ma (U-Pb dating)

Cadomian granite, gneiss566-595 (U-Pb dating)

Edia

cara

n-Ca

mbr

ian

^

.

^^^ ^

. . ..

. . . .. .

Peridotite, serpentinite

Gabbro, locally layered

Pillow lava, massive lava

Late Cretaceous pelagicsediments

Tectonic melange, turbiditeepiclastic rocks with basalticsill, Late K-Early P. limestones

L. Cretaceous-EarlyPaleocene pelagic limest.

Late Cretaceous-Paleoceneturbidites

Late

Cre

tace

ous-

Early

Pal

eoce

ne

Plio-Quaternaryandesite-dacite

Quaternary Ararat &Tendurak basalts

Fig. 4. Simplified geological map of Khoy–Maku ophiolites (modified after Ghoraishi and Arshadi, 1978 for Khoy and Alavi and Bolourchi, 1975 for Maku 1/250,000 maps).


and Stern (2011). The Dehshir ophiolite mantle sequence com-prises harzburgite, clinopyroxene-bearing harzburgite, and cumu-late rocks. The Dehshir ophiolite crustal section (�400–500 mthick) comprises pillowed basalts, basaltic and basaltic–andesiticmassive flows, and a basaltic–dacitic sheeted dike complex. Plagi-ogranite occurs both as dikelets injected into isotropic gabbros andas small plugs emplaced in metamorphosed (lower greenschistfacies) pyroclastic rocks.

3.2.3. Shahr-e-Babak ophioliteThe Shahr-e-babak ophiolite (Table 1) lies �100 km SE of Deh-

shir and is bounded to the west by the Dehshir–Baft fault, to theSSW by SNSZ metamorphic rocks and to the NNE by the Dehaj–Sarduiyeh magmatic belt, part of the Cenozoic Urumieh–Dokhtararc. It consists of both mantle and crust sequences. The mantlesequence is dominated by highly serpentinized harzburgites. Iso-tropic gabbros as small lenses cut by plagiogranitic veins are com-mon within the mantle sequence. The volcanic sequence iscomposed of basalt, andesite, dacite and rhyolite associated withpyroclastic rocks. The lavas are either massive flows or associatedwith pyroclastic rocks and interbedded with Coniacian–Maastrich-tian pelagic sediments (Fig. 6D). Massive and pillowed lavas overliethe interbedded volcanic sequence. Shallow dioritic–granitic plu-tons and trachytic dikes intrude the massive lavas.

3.2.4. Balvard–Baft ophioliteThe Balvard–Baft ophiolite (Table 1) defines a 5–10 km wide

WNW-trending belt that extends NW toward Shahr-e-Babak andSE to the Dare–Pahn and Haji Abad ophiolites. The Balvard–Baftmantle sequence consists of harzburgite, minor lherzolite with dia-basic dikes and pockets of isotropic and pegmatitic gabbro. Crustalunits consist of pillow lavas, basaltic–andesitic–dacitic lava flows,and basaltic–andesitic–dacitic sills in pyroclastic rocks and total>2300 m thick. Pyroclastic rocks rest unconformably on basalticlava flows (Shafaii Moghadam et al., 2013a). The Balvard–Baftophiolite is in fault or unconformable contact with Middle to LateEocene sedimentary-volcanic sequences related to the Urumieh–Dokhtar arc.

3.3. Sabzevar–Torbat-e-Heydarieh ophiolitic belt

The Sabzevar–Tobat-e-Heydarieh ophiolite belt (STOB) is situ-ated in NE Iran (Fig. 2) where it trends E–W for over 400 km. STOBis bordered to the north by the major Sangbast–Shandiz strike-slipfault delimiting the Binalud Mountains. To the south, the STOB isbounded by the major Dorouneh sinistral strike-slip fault (Fig. 8)delimiting the Lut Block. STOB comprises three main alignments(Fig. 8), separated by the Paleocene–Eocene Oryan sedimentarybasin: (1) ophiolites NNW of Sabzevar (the Sabzevar ophiolite);

.... .

++

Late

Cre

tace

ous

Khoy

oph

iolit

esSu

pra-

ophi

oliti

c se

ries

Mantle lherzolite-harzburgite

Gabbroic-pyroxenitic dike

Diabasic dikeUltramafic-mafic cumulates

Gabbroic lens

Wehrlitic intrusion

Massive basaltic sheet flows

Diabasic dike

Pillow lava sequenceHyaloclastic rocks

Volcanic breccia

Pelagic limestones

TurbiditesEpiclastic breccias & tuffs

Pillow lava

Ankaramitic breccias & lavas

Radiolarite-tuff-breccia

Khoy ophiolite

Maku ophiolite

Maku-Mazraeh section

Pelagic limestone

Radiolarite/tuff

Pillow lava sequence(Ankaramitic)

Crustal gabbros

++. . .. . Gabbroic lens

Gabbroic-pyroxenitic dike

++. . .. . Gabbroic lens

Mantle lherzolite

Turbidite-sandstone

Tuff-breccia

Basalticfragments

Epiclastic rocks

Basaltic sillcalc-alkaline

Late Cretaceouspelagic sediments

Basaltic sill

Epiclastic rocks

Basaltic sill/dikeOIB-type

OIB-type basalts

Siah-Cheshmeh section

(Modified after Khalatbari Jafary et al., 2003)

(Modified after Poor Mohsen et al., 2010)

1km

500

m

500

m

Fig. 5. Simplified stratigraphic columns diplaying idealized internal lithologic succesions in the Late Cretaceous–Early Paleocene Khoy (A) and Maku ophiolites (B), (modifiedafter Khalatbari-Jafari et al., 2003 for Khoy and Poor Mohsen et al., 2010 for Maku ophiolites).


(2) ophiolites SSW of Sabzevar (the Oryan–Bardaskan ophiolites);and (3) ophiolites north of Torbat-e-Heydarieh. These ophiolitesare overlain by Upper Cretaceous to Paleocene extrusive rocks,associated with volcanoclastic sediments, pelagic limestones andradiolarian cherts. To the NNE, the Sabzevar ophiolite is associatedwith mainly mafic protoliths metamorphosed to lawsonite-bearingblueschist (lawsonite, epidote, albite, crossite, phengite, garnet),granulite and greenschist (Rossetti et al., 2010; Omrani et al.,2013). The Paleocene-Eocene sedimentary basin separating thethree ophiolitic alignments is composed of transgressive flyschatop the ophiolite with arc volcanic remnants. We briefly discussthe three ophiolite remnants below, which are summarized inTable 2.

3.3.1. Sabzevar ophioliteOphiolites NNW of Sabzevar define a belt about 150 km long

and 10–30 km wide along the northern margin of the Lut Block.This ophiolite is part of a northern branch of Neotethys known asthe Sabzevar Ocean that opened and closed during the Late Creta-ceous (Lensch et al., 1980; Sengor, 1990).

Harzburgite, lherzolite, dunite and chromitite are the majorcomponents of the Sabzevar mantle sequence. Large chromititedeposits occur in the Gaft and Forumad regions (ShafaiiMoghadam et al., 2013b). Dunite occurs as lenses/layers or irregu-lar sill-like intrusions within harzburgites (Fig. 6E). Wehrlitic(rarely gabbroic) sills and dikes in the Gaft region crosscut all unitsincluding chromitite, dunite and harzburgite (Shafaii Moghadamet al., 2013b).

Sabzevar crustal rocks are divided into five subunits: (1) isotro-pic gabbro lenses; (2) cumulate gabbro/gabbronorite/leucogabbro(with minor diorite) with local layering associated with minorultramafic cumulates in Soleimanieh, Tabas and Baghjar; (3) ahighly fragmented and sheared sheeted dike complex, but clearlywith dike-into-dike relationships, with early basaltic to andesiticbasaltic dikes and late dacitic dikes; (4) plagiogranite lenses. Theseare often found within cumulate gabbro associated with abundantcrosscutting micro-dioritic to dacitic dikes and as small pockets

within the sheeted dike complex; and (5) pillowed and massivebasalts. Shojaat et al. (2003) recognized three chemical varietiesof mafic rocks: (1) N-MORB basalt and gabbro; (2) E-MORB basaltsand (3) arc basalts. Baroz and Macaudiere (1984) distinguishedfour lithostratigraphic units overlying the ophiolite, from Campa-nian to Paleocene, including alkaline to calc-alkaline pillow lavas,litharenites, breccias and agglomerates with pelagic sediments.The lavas grade upwards into turbiditic sandstone/breccias andpyroclastic deposits containing OIB-type basaltic fragments. LateCretaceous to Paleocene pelagic limestone is interlayered withthese turbidites. Pelagic sediments also stratigraphically coverthe pillow lava sequence (Fig. 7C). The geodynamic reconstructionof Shojaat et al. (2003) included: (1) generation of back-arcbasin oceanic crust in middle Late Cretaceous time; (2) depositionof the volcano-sedimentary series, fed from a Late Cretaceous–Paleocene arc; and (3) collision of the arc with the Lut block.

3.3.2. Oryan–Bardaskan ophioliteThe Oryan–Bardaskan ophiolite (Fig. 8) is mostly composed of

volcanic rocks, although mantle peridotites with crosscutting dia-basic dikes, chromitites and gabbros are also common. Ultramaficcumulates including plagioclase- and amphibole-bearing lherzo-lites and harzburgites are abundant, grading upward into coarse-grained cumulate gabbros. The ophiolite is crosscut and coveredby younger, Eocene plutonic and volcanic rocks, which showfaulted contacts with the Cadomian(?) Taknar basement (Fig. 8).There are no detailed studies on this STOB segment. The sedimen-tological and paleogeographical features of Mesozoic and Cenozoicstrata of the Oryan basin are considered as a series of gravitationalnappes (Lindenberg et al., 1983). Oryan–Bardaskan ophioliticmélange is interpreted as tectonic breccia at the base of the oldestnappes. Volcano-pelagic series of the Oryan zone include Cenoma-nian to Maastrichtian pelagic sediments interbedded with pyro-clastic and andesitic to dacitic lavas (Lindenberg et al., 1983).This sequence grades upward into shallow water sediments ofMaastrichtian to Paleocene age (Lindenberg et al., 1983). Thesestrata are overlain by Early Eocene to early Middle Eocene Oryan

Fig. 6. Field photographs of Outer Zagros ophiolites including Khoy–Maku ophiolites. A – The stratigraphic position of pelagic limestones between thick volcanic sequences ofthe Maku ophiolites. B – Pillow lavas near Kherran village (Kermanshah ophiolite). C – Layered leucogabbro, olivine-bearing melanogabbro and pyroxenite cumulate sillswithin Neyriz mantle sequence. D – Late Cretaceous pelagic limestones interbedded with pyroclastic rocks in Shahr-e-Babak ophiolite. E – Discordant dunites within mantleOpx-rich harzburgites in Shareh region (Sabzevar ophiolites). F – The faulted contact between Bajgan metamorphic complex and Sorkhan–Rudan ultramafic rocks within theouter Makran ophiolites.


marine sediments (lower and middle Oryan sediments). Lower andmiddle Oryan sediments include marine conglomerates, turbiditicsediments, reefoid limestones, marls and Nummulitic limestones(Lindenberg et al., 1983). These sediments are overlain stratigraph-ically by late Middle Eocene upper Oryan series of continentalaffinity. These relationships indicate that the STOB seaway wasopen until upper Middle Eocene time.

3.3.3. Torbat-e-Heydarieh ophioliteThis ophiolite lies N of Torbat-e-Heydarieh and constitutes the

southeastern STOB covering an area 60 km long and 50 km wide(Fig. 8). It is mostly composed of mantle peridotite, especiallyOpx-rich harzburgite with minor dunite and chromitite. Diaba-sic–gabroic–pyroxenitic and plagiogranitic dikes crosscut the man-tle sequence. Abundant massive and pillowed basalts aremetamorphosed to greenschist to lower amphibolite facies. LateCretaceous pelagic sediments associated with pyroclastic rocksare interlayered with and conformably overly the lavas. The ophi-olite is unconformably overlain by Paleocene-Eocene conglomerateand sandstone.

There is also a long arcuate belt of ophiolites and ophioliticmélange that stretches for �150 km from east of Torbat westwards

to Cheshmeshir and beyond (Fig. 8). This is the largest unstudiedophiolite in Iran.

3.4. Birjand–Nehbandan (Eastern Iranian) ophiolitic belt

Another belt of Cretaceous ophiolites is found in eastern Iran,adjacent to the western margin of the Afghan block (ShafaiiMoghadam and Stern, 2014; see Fig. 1). The N–S trending Sistansuture demarcates the boundary between the Lut (eastern segmentof the central Iranian micro-continent) and the Afghan continentalblocks (Table 2). The main ophiolites from north to south includethe Birjand ophiolite, the Nehbandan ophiolite complex (Delavariet al., 2009; Saccani et al., 2010) and the Tchehel Kureh ophiolite(Fig. 9). Generation and emplacement of these ophiolites reflectthe consumption of the Sistan arm of Neotethys with subductionpolarity to the east, beneath the Afghan block, and the subsequentcollision between the Lut and Afghan continental blocks (e.g.,Tirrul et al., 1983). Radiolarites of the Ratuk complex in the SistanSuture Zone are characterized by two faunal assemblages of EarlyAptian and middle Late Albian ages (Babazadeh and De Wever,2004). Deep-water sedimentation continued until Early Eocenetime (Saccani et al., 2010). Tirrul et al. (1983) suggested that

++

++++

Lawsonite-blueschist,epidote amphibolite

Retrograded granulite

Melt segregationsTonalitic to trondhjemitic lensesU-Pb dating= 105-107 Ma (Rossetti et al., 2010)

Isotrope gabbro/diorite

Plagiogranite dikelet

Diabasic dikeGabbroic dike swarm

Diabasic-pegmatite gabbroto pyroxenitic dike

Podiform chromitite

Melt conduits/concordantdeep seated intrusives

Discordant dunite lens/dike

Layered ultramafic-maficcumulates

Dacitic/diabasic dike

Plagiogranitic lens

Sheeted dike complex Plagiogranite

MAN

TLE

SEQ

UEN

CE

CR

UST

AL S

EQU

ENC

E

Calc-alkaline to IAT pillow lavaLate Cretaceous pelagic limestone

OIB-type pillow lava

Late

Cre

tace

ous

ophi

olite

s

+ ++

=

== ==

= =

= =

== =

= =

== =

= =

== =

= =

== =

= =

== =

= =

=

=

=

=

=

=^^^ ^^

^ ^ ^ ^^^^ ^

^^^^

^^^ ^

^ ^ ^^^

^

^ ^^^ ^ ^

^^

^^

^^

^ ^ ^

^ ^ ^ ^ ^

Late Cretaceous-Early Paleocene?pelagic limestone

Paleocene to Eocene tectonic melangewith Eocene red-type conglomerates

Eocene volcanic rocks &pyroclastic rocks

Arc

lava

s an

d se

dim

ents

Miocene red-type sandstonesMarls & limestones

Pliocene conglomerates

Dacitic-rhyolitic dome

(C) Sabzevar ophiolite

+ ++

+

++

+

++

+++

++

+

+

+

.... ..

... . .. . ..

+++

+

++

Opx layering

Mantle lherzolite, harzburgitedepleted harzburgite & dunite

Turbiditic sequence with intercalation ofpelagic limestone & OIB pillow fragments

(Late K-early Paleocene?)

+ +

+ +++

++ ++

_ _____ ___ _ _ ___

(A) Neyriz ophioliteTarbor Formation

Unconformity

^ ^ ^^^ ^massive lava

Late K pelagic limestonesheeted dike complex

pillow lava ^^^^^ ^

coarse-grained gabbroplagiogranite

wehrlite, pyroxenite,gabbro cumulates __ ___ _

_

__impregnated peridotite

+ + + ++ + + isotropic gabbro-

leucogabro

chromitite pod

++

++

++

++++++

+ +++ + + +

pegmatite gabbro

gabbroic-diabasic dike/sill

harzburgite

amphibolitic sole

residual dunite

tectonic contact

+ + + ++ + ++

++

++

++

isotropic gabbro-gabbronorite

tectonic contactgarnet amphibolite

chromite pod

diabasic dike

++++++

+ +++ + + +pegmatite gabbro

gabbroic-pyroxenitic dike

coarse-grainedsulfide-bearinggabbro

. . . .. .. .. .. ..... ... .... .........

...

...

melt impregnation

^ ^ ^^ ^^^^^ ^

pyroxenitic sill

^^^^^^ ^^^ ^^^

+++ ++++ ++++amphibole gabbro

Sheeted dike complex

plagiogranite

pillow lavamassive lava

pelagic limestonechert

neritic limestonediabasic sill

(B) Nain ophiolite

500

m50

0 m

3 km

(not sole)

Fig. 7. Simplified stratigraphic columns displaying idealized internal lithologic succesions in a typical Outer Zagros (A) and Inner Zagros ophiolites (B) (Neriz and Nainophiolites). (C) Idealized lithological succesions in the Sabzevar Late Cretaceous ophiolites.

^ ^^ ^

^ ^^

^ ^^ ^

^ ^^

^^ ^

^^^

^^ ^

^

+ + + ++

^^^^ ^

^^^^^^^^^^^^^ ^ ^ ^

+ + ++ + +

++ + +

+

^ ^^^ ^ ^ ^

~~~ ~~~~~

Soltanabad

~ ~ ~ ~

SabzevarBaghjar

^^^ ^ ^ ^ ^ ^ ^

^

Forumad

Joghatay

Garmab

30 km

57°4

5΄

57°1

5΄

58°1

5 ΄

36°15΄

+++ + +

+ + + + ++ ++ +

+ ++

++

Banghan

Oryan

Hamireh

Dorouneh Fault

Paybaz^ ^ +Ghasem abad+ +

++

+ ++ +++

+ ++

+ ++ +

++

+ +++++ + + +

^ ^ ^ ^ ^^ ^^

Bardaskan Kashmar

+

+ ++

^^̂

^

^^ ^ ^^ ^

^ ^ ^^

^^

^

^^

^ ^^

^^^^

^

^

^^

^

^

^^

^ ^

^^

^^^

^^^ ^^

^ ^ ^^

^^

^

Cheshmeshir

^^^

^^

^ ^^^

^^^ ^

+ + +++ +++ +

Dehnow

+ + + Raush+

+ ++

+++

+

+ +

^^

^^^ ^ ^

^ ^ ^ ^ ^

+ + + + + +++++++++++ + +

+ +++ + +

++

++

Uchpalang

+

+++

++

^^ ^

^ ^^

^^

^^ ^^

AzghandTorbat-e-Heydarieh

Fariman+ +

++

+

Derakht-e-Senjad

Robat-e-SangKadkan

++

++++

+ ++

Qale Now

Abbasabad

^^ ^ ^ ^ ^ ^^^^ ^

^ ^ ^

^^^ ^

^^^ ^

^^

^ ^35°15΄

35°30΄

35°45΄

36°00́

58°4

5΄

59°1

5΄

59°4

5 ΄

^ ^^ ^ ^

^

Lut Block

Paleocene-Eocene Sedimentary

Neyshabour

Torbat-e-Heydarieh ophiolite

Sabzevar ophiolite

Oryan-Bardaskan ophiolite

Gaft

+

~

++

~~ ~

^ ^^

Metamorphic rocks (HP)

Serpentinite, peridotite

Cumulate gabbro

Lava flow, pillow lavatectonic melange

Pelagic sediments

Late Cretaceous-Early Paleoceneophiolite

Basaltic-andesiticDacitic dome (adakite)

-dacitic lavas, breccia

Late Cretaceous-

+ ++ Diorite-granodiorite

Meta-rhyolite; schistTaknar Formation

Precambrian (Lut basement)

Eocene arc

Fig. 8. Geological map of the Sabzevar–Torbat-e-Heydarieh region, north of the Dorouneh Fault, with emphasis on the distribution of ophiolitic and arc-related rocks.


isolated Turonian (�90 Ma) limestone blocks represent Birjand–Nehbandan cover.

Subduction-related blueschists and eclogites associated withinBirjand ophiolites give Early to Late Cretaceous radiometric ages(Fotoohi Rad et al., 2005; Brocker et al., 2010; Brocker et al.,2013). P–T estimates for eclogite and blueschist indicate ca. 1.5–2.4 GPa and ca. 450–650 �C, whereas ca. 0.5–0.7 GPa, 520–590 �C

was reported for epidote–amphibolite facies rocks (Fotoohi Radet al., 2009). These high-pressure metamorphic rocks are uncon-formably overlain by Maastrichtian Rudist-bearing limestones(Tirrul et al., 1983).

Birjand ophiolites are divided into Neh and Ratuk complexesand Sefidabeh sedimentary basin deposits (Tirrul et al., 1983)(Fig. 9). The Neh and Ratuk complexes, which represent an accre-

PAKISTANAFGHANIS

TAN

IRAN

o59 E

o30 N

o31

o32

o33

o60 o61

The

Sistan

SutureZone

alluviumvolcanic rocksintrusive rockssedimentary rocks (Senomanian-Eocene)volcanic rocks (Maastrichtian-Paleocene)marls and turbiditesphyllites

basement rocks (Pre-Late Cretaceous)

Eocene-PlioceneSefidabehBasin deposits

Neh and Ratuk Complexes (Senonian-Eocene)

AFGHAN BLOCK

LUT BLOCK

Nehbandan

Birjand

Birjandophiolite

Bandan Mine

50 km

Tchehel Kureh ophiolite

Nosrat Abad

Mantle tectonite

Podiform chromitite

Diabasicdike

E-MORB/IAT typegabbroic dike/lens

Pillowed/massive lavasIAT/E-MORB

Early-Late K limestone-radiolarite

Late Cretaceousflysch deposits

flysch depositsPaleogene

Paleogene-Neogenevolcanic rocks+ ++

++++

SSZ-like sequence (Saccani et al., 2010)Gabbro

Birjand ophiolite

Nehbandan ophiolite

GabbronoriteOlivine websterite

Pyroxenite

500

m

Mantle tectonite

Tertiary sedimentaryrocks

500

m

Plagiogranite

Dunite

Troctolite

MORB-like sequence (Saccani et al., 2010)

Pelagic limestoneMassive basaltPillow lava

High-level gabbro

Cumulate gabbro

Foliated gabbro

Troctolite

Gabbro

Dolerite

Tertiary sedimentaryrocks

Mantle tectonite

500

m

Mafic-ultramafic rocks

Fig. 9. Sketch of the Sistan suture zone and its ophiolites. The main ophiolites are, from north to south, the Birjand ophiolite, Nehbandan ophiolite and the Tchehel Kurehophiolite. The left side lithological sections are pseudo-stratigraphic columns of the Birjand and Nehbandan ophiolites. Two main kinds of tectonically distinct ophiolitesequences in the Nehbandan complex (i.e., MORB and IAT-like) are from Saccani et al., 2010.


tionary prism and a forearc basin respectively, are subdivided into:(1) ophiolites with early Aptian to middle Late Albian and Cenoma-nian to Maastrichtian pelagic sediments; (2) Late Cretaceous–Eocene phyllites; and (3) Late Cretaceous–Early Eocene unmeta-morphosed marine clastic sediments including sandstone and mar-ly turbidite (Fig. 10). Detritus includes fragments of ophioliticchert, basalt and gabbro. Sedimentary fill of the Sefidabeh basin(Fig. 9) includes Cenomanian to Eocene clastic deposits withdeep-marine carbonates and calc-alkaline lavas (Tirrul et al.,1983; Camp and Griffis, 1982).

Cpx-bearing harzburgite, harzburgite, dunite and (podiform)chromitite lenses are common in the Birjand mantle sequence(Fig. 9). Crustal rocks include massive to pillowed lavas with MORBand OIB affinities respectively (Zarrinkoub et al., 2012) similar to

the Nehbandan ophiolites, although IAT massive lavas are common.Troctolites, olivine gabbros and leucogabbros are also common(Zarrinkoub et al., 2012). Pelagic sediments associated with pyro-clastic rocks cover the Birjand ophiolite volcanic sequence (Fig. 9).

The Nehbandan ophiolites comprise a mantle sequence (harz-burgite-Cpx bearing harzburgite and depleted harzburgite) withtwo different crustal units including (Saccani et al., 2010)(Fig. 10): (1) MOR-type ultramafic cumulates (dunite–wehrlite–troctolite), cumulate gabbros, high-level gabbros with plagiogran-itic dikes and basalts and (2) SSZ-type ultramafic cumulates (web-sterite and pyroxenite), gabbronorites and gabbos, withoutvolcanic rocks.

On the basis of mantle tectonite chemistry, Saccani et al. (2010)suggested that Nehbandan MOR-like tectonites were generated at

Pakist

an 26˚N

63˚E

63˚E

28˚N

57˚E

57˚E

26˚N

28˚N

Gulf of Oman 100 Km

150

kmPresent vector of

the subducting plate

Jaz Murian DepressionFM

Kahnuj ophiolite

Makran Accretionary Prism

Accretionary PrismSaravan

Main Makran Accretionary Prism(Cenozoic)

Upper Miocene-Pliocene neritic & coastal sediments

Lower-Upper Miocene neritic sediments

Upper Oligocene-Lower Miocene flysch turbidites

Lower Eocene-Lower Oligocene flysch turbidites

Ophiolites

Coloured melange complex (Outer Makran Ophiolite Belt)(Jurassic-Lower Paleocene)

Band-e-Zeyarat/Dare Anar complex(Lower Cretaceous-Lower Paleocene)Ganj complex (Cretaceous)Rameshk-Mokhtarabad complex

(Lower Cretaceous-Lower Paleocene)

FM Fanuj-Maskutan complex

Metamorphic complex

Bajgan-Durkan complex (Jurassic, upper Paleozoiccarbonates of shelf facies over Lower Paleozoic?

metamorphic rocks)

Deyadar high pressure metamorphic rocks(blueschists)

Saravan Accretionary Prism (Cenozoic)

Lower Eocene-Lower Oligocene flysch turbidites

Shah Kuh granodiorite intrusions (Oligocene)

Inne

r Mak

ran

Oph

iolit

e Be

ltSorkhband & Rudan

Minab

Fanuj

Rameshk

Zendan Fault

1

2 34

complexes

Fig. 10. Simplified geological map showing the geotectonic zones in the Makran region of southern Iran (modified after McCall, 1983, 1997). Numbers show the reconstructedsequences in Fig. 13.


a mid-ocean ridge and that the mantle tectonites with SSZ-likeaffinities formed above an east-dipping subduction system thatnucleated after spreading stopped.

3.5. Makran ophiolites (SE Iran) including Kahnuj ophiolites

The Iranian Makran is an accretionary prism developed above aNorth-dipping subduction zone subducting Indian Ocean crust(Siddiqui et al., 2012). The Makran accretionary prism extendsfor 450 km, from SE Iran to SW Pakistan. Makran comprises aregion about 200 km wide in SE Iran (Fig. 10) between the JazMurian depression and the Gulf of Oman. In the north, in the Cha-gai and Ras Koh mountain ranges, there are rock sequences thatrepresent the associated magmatic arc (Siddiqui et al., 2012).

There are three important zones in Iranian Makran, from S to N:(1) the Makran accretionary prism which continues to form as aresult of subducting the Indian plate and the sediments on itbeneath the central Iranian block; (2) the Jaz Murian depression,

which may be a sediment-filled Mesozoic back-arc basin (McCalland Kidd, 1982; McCall, 1997; Glennie et al., 1990) or an intra-arc basin (Shahabpour, 2010); and (3) Cenozoic volcanic and plu-tonic rocks of andesitic to rhyolitic composition which reflect arcmagmatism related to the Makran subduction system. Below wedivide ophiolites in the region into two parts: (1) Makran ophio-lites including Jurassic–Early Paleocene Rameshk–Mokhtarabadand colored mélange complexes; and (2) Kahnuj ophiolite, whichis the NW continuation of the Inner Makran ophiolite belt.

3.5.1. Makran ophiolitesAccording to McCall (1983) and McCall and Kidd (1982), the

Makran region can be divided into 8 geotectonic provinces, forthe most part presented from N to S (Fig. 11):

3.5.1.1. Jaz Murian depression (4 in Fig. 11). This is a Late Plioceneepeirogenic depression elongated about 300 km long East–West.This region is defined by Quaternary sediments, which are

1Southern Makran

Cre

tace

ous

PaleoceneColored melange (ophiolite)layered ultramafic,radiolarite, globotruncana

limestone

Thick flysch sequenceEocene

OligoceneThick flysch sequence

Thick flysch sequenceMio

cene

Lower Pliocene Neritic clastic sediments

U. Pliocene-Pleistocene Continental fanglonerates

2Bajgan-Durkan block

Low

er P

aleo

zoic

Cre

tace

ous

Albian-Aptian

Lower Paleocene

Eocene

Oligocene

Metamorphic rocksbasement of the

microcontinental block

Platform limestoneshighly deformed withlarge included raft of Jurassic, Permian, Carboniferous platform

limestones

Neritic clastic sediments

3Inner Makran Ophiolitic Belt

Late

Jur

assi

c-C

reta

ceou

s

Layered ultramafic-mafic rocksgabbros, trondhjemites

Sheeted dike complex

Pillow lavas

Deep water pelagic limestones &radiolarites

Lower Paleocene

Eocene

OligoceneNeritic clastic sediments

& shallow water limestones

4Southern edge of Jaz Murian depression

Neritic clastic sediments& shallow water limestonesEocene

low

er P

aleo

zoic

/Pre

-Cam

bria

n?

Metamorphic rocks of theDeyader complex, (schists,quartzites, marbles), includingpatches of blueschists whichmay represent Cretaceoussubduction & metamorphism

Outer Makran Ophiolitic Belt

Kahnuj ophiolitePelagic limestone

Pillow lava

Sheeted dike complex(K-Ar=91.6-65.4 Ma, WR)

Diabasic/amphibolegabbroic dike

(K-Ar=136.6 Ma; Amp)

Plagiogranite(K-Ar=118.2 Ma, WR)

Granitic dike(K-Ar= 88.6 Ma, Chl)

(89.4 Ma, Orth)(92.6 Ma, Orth)

Gabbroic agmatite(K-Ar= 121.4 Ma, Chl)

(127.6 Ma, Chl)

Uralitized gabbro-dioritetrondhjemite

(K-Ar=80.3 Ma, Feld) Mylonitic gabbro/amphibolite(K-Ar=139.4 Ma, Amp)

(142.2 Ma Amp)

Layered gabbro(K-Ar=519 Ma, Plag)

438 Ma, Plag140.7 Ma, Amp144.4 Ma, Amp156.5 Ma, Amp

Isotropic gabbro(K-Ar=517 Ma, Plag)

168 Ma, Plag213.6 Ma, Amp

Modified after Kananian et al., 20011

km

Fig. 11. Generalized stratigraphic columns showing the reconstructed internal sequences in the Makran (modified after McCall, 1997) and Kahnuj ophiolites (modified afterKananian et al., 2001). The K–Ar ages in the Kahnuj ophiolite are shown for clarity. Analyzed phase for K–Ar are plagioclase (Plag); amphibole (Amph); chlorite (Chl);orthoclase (Orth), feldspar (Feld) and whole rock (WR).


underlain by Eocene shallow water limestones and metamorphicrocks (column 4 in Fig. 11). The Deyadar complex (Figs. 10 and11 (4)) is composed of metamorphic rocks including blueschistsand is interpreted as a site of Mesozoic subduction (McCall, 1997).

3.5.1.2. Inner Makran ophiolite belt (3 on Fig. 11). There are threedistinct ophiolites in this belt (Fig. 11; McCall and Kidd, 1982)comprising from W to E: (a) Band-e-Zeyarat/Dare Anar complex,an Early Cretaceous to Early Paleocene tholeiitic suite consistingof cumulate gabbro overlain by high-level isotropic gabbro, tron-dhjemite, diabasic sheeted dike complex, pillow lava and pelagicsediments; (b) Cretaceous Ganj complex, which is a calc-alkalinesequence thrust on top of tholeiitic suite ophiolites, and (c)Rameshk–Mokhtarabad complex, which is an Early Cretaceous–Early Paleocene ophiolite consisting of fragmented ultramafic–mafic cumulates, high level gabbro, trondhjemite, sheeted dikecomplex, pillow lava and pelgic sediments.

3.5.1.3. Bajgan–Durkan complex. This zone is up to 40 km wide andconsists of Early Paleozoic metamorphic rocks of the Bajgan com-plex overlain by mainly Mesozoic shelf carbonates of the Durkancomplex. The Bajgan complex includes amphibolites, marble,calc-silicate rocks, and schists with abundant meta-volcanic rocksand mafic to felsic intrusive rocks. Eastward, the Bajgan complex isoverlain by shelf limestones of the Durkan complex (McCall andKidd, 1982). The Durkan complex also has tectonic windows ofCarboniferous, Permian and Jurassic shelf limestones (Fig. 11).The Durkan complex is mainly composed of Mesozoic shelf

carbonates, sandstones and argillic rocks with interbedded lavasand small mafic intrusions (Kananian et al., 2001). Pillow lavas,cherts, lapilli tuffs and minor mafic–ultramafic intrusions are alsocommon (McCall, 2002). The Bajgan–Durkan complex is consid-ered as a narrow continental block, which could be the SE contin-uation of the Sanandaj–Sirjan zone (McCall and Kidd, 1982; McCall,2002).

3.5.1.4. Colored mélange zone (outer Makran ophiolite belt). Thismélange is located south of the Bajgan–Durkan complex (Sorkh-band and Rudan complexes in Fig. 11) and consists of serpentinites,mafic–ultramafic rocks, pillow lavas, pelagic limestones, radiola-rites and distal turbidites with minor outcrops of andesites, rhyo-lites, andesitic tuffs, and Lower Cretaceous reefal limestones. Thismélange is suggested to have formed in the trench of a North-dip-ping subduction zone by scraping off fragments of the downgoingplate during Late Cretaceous to Early Paleocene time (McCall andKidd, 1982; McCall, 2002), thus it represents the northernmost partof the Makran accretionary prism, which continues to grow today.

The four southernmost Makran zones reflect southwardsgrowth of the Makran Accretionary Prism during Cenozoic timeand include lower Eocene to Pliocene sequences of calcareousand turbiditic flysch, evaporites, reefal limestone, gypsiferousmudstone, deltaic sandstone and estuarine conglomerate.

The ophiolites to the north and south of the Bajgan-Durkancomplex are considered by McCall (1997) to respresent two dis-tinct oceanic basins. The Inner Makran ophiolites to the north com-prise the Band-e-Zeyarat/Dare Anar, Ganj and Rameshk/


Mokhtarabad (McCall 1985) complexes, formed as a deep basinassociated with radiolarites and pelagic limestones interbeddedwith ophiolitic basalts. The Ganj ophiolite complex exposes anintermediate to felsic sheeted dike complex and calc-alkalinebasaltic–andesitic (pillow) lavas. Turbiditic sediments intercalatedwith lavas show Campanian to Maastrichtian ages (McCall, 2002).Eocene–Oligocene sediments lie unconformably on the Ganj com-plex. The Band-e-Zeyarat complex exposes layered ultramafic–mafic rocks and trondhjemite below Dare–Anar sheeted dikesand pillow lavas. The Rameshk complex exposes layered ultra-mafic–mafic rocks including harzburgite, troctolite, anorthosite,gabbro, leucogabbro, diorite and tonalite/trondhjemite overlainby Mokhtarabad complex rocks, a sequence of pillow lavas withinterbedded Late Jurassic to Early Paleocene radiolarites and Globo-truncana-bearing Santonian–Maastrichtian limestones (McCall,2003).

Ophiolites to the south of the Bajgan–Durkan zone are tectoni-cally fragmented (colored mélange zone and/or outer Makranophiolites), consisting of a jumble of large blocks, mainly of ultra-mafic–mafic plutonic rocks and mafic lavas as well as pelagic sed-iments. The outer Makran ophiolites include two relatively intactophiolites, the Sorkhband and Rudan complexes (McCall, 1985),which are 17 km long and 9 km wide, composed mainly of dunite,harzburgite and stratiform-type chromitite with pyroxenite/wehr-lite sill-like intrusions Figs. 6F) and minor isotropic to coarse-grained gabbros at the top of the sequence. This complex showsfaulted contact with Bajgan–Durkan metamorphic rocks (Fig. 6F).Biomicrites intercalated with outer Makran ophiolite pillow lavasare dominated by Campanian–Maastrichtian microfaunas,although there are also Cenomanian, Turonian, Coniacian and San-tonian microfossils (McCall, 2002). Radiolarites associated with pil-low lavas and pelagic limestones range from Pliensbachian(Jurassic) to Coniacian.

3.5.2. Kahnuj ophiolitesThe Kahnuj ophiolite covers more than 600 km2 in NW Makran

and is the northwestern continuation of the Inner Makran ophio-lites (Figs. 2 and 10). McCall (1985) divided the Kahnuj ophiolitesinto (1) the plutonic Band-e-Zeyarat complex comprising layeredand non-layered gabbroic cumulates, trondhjemites and a transi-tion zone including sheeted dike complex, and (2) the Dare Anarvolcanic sequence including basaltic to andesitic pillowed andmassive lavas, associated with pelagic sediments. The Kahnuj ophi-olite is separated from the Ganj complex to the east by the Jiroftfault. To the west, the Kahnuj ophiolite is separated from the Baj-gan metamorphic complex by the Sabzevarn fault. Outer Makranophiolites are present to the west and south of the Bajgan complex(Fig. 10), made of basaltic pillow lavas and pelagic pink limestones(Kananian et al., 2001). Kananian et al. (2001) distinguished 6 mag-matic units in the Kahnuj ophiolites, from bottom to top, including(Fig. 11): (1) a thick, layered gabbroic unit of banded troctolite,olivine gabbro, gabbronorite, leucogabbro and anorthosite withminor wehrlitic intrusions. This unit makes 40% of the whole Kah-nuj ophiolite; (2) isotropic and uralitized gabbros, overlying thelayered gabbros. (3) highly deformed fine-grained amphiboliteand mylonitic gabbro; (4) an agmatite unit in which the gab-broic/diabasic rocks at the base of the sheeted dike complex arefragmented and float in a whitish trondhjemitic matrix. These fourunits combined are equivalent to the Band-e-Zeyarat complex ofMcCall (2002, 2003); (5) a sheeted dike complex mainly made ofnorth–south striking diabasic dikes (65� dip to the E) that occupyabout 2–2.5 km2 (Arvin et al., 2001), and (6) an extrusive unit (DareAnar complex) mainly made of basaltic pillow lavas and associatedpelagic sediments. Pillow lavas of the Dare Anar complex areintruded by numerous diabasic and gabbroic dikes as well asfeldspathic wehrlitic and trondhjemitic dikes.

4. Age constraints of Iranian ophiolites

In this section we synthesize age information for Iranian ophio-lites, using both biostratigraphic ages (based on microfossils) andradiometric ages (such as K–Ar, Ar–Ar and U–Pb ages) from IranianMesozoic ophiolites. Our synthesis is graphically presented inFig. 12.

4.1. Zagros outer belt ophiolites

Age constraints for outer Zagros ophiolites (including Khoy–Maku) are summarized in Table 1 and Fig. 12. Based on K–Ar ages,Khalatbari-Jafari et al. (2003, 2004) distinguished two ophioliticcomplexes in the Khoy region; (1) older ophiolites composed ofhuge slices of metamorphic rocks (amphibolites, gneisses andmica-schists) and harzburgitic to lherzolitic tectonites; and (2)younger (Late Cretaceous) unmetamorphosed ophiolite. Khoy lay-ered gabbros yield plagioclase K–Ar ages of 100.7 ± 6.0 and72.6 ± 5.0 Ma (Khalatbari-Jafari et al., 2003). Limestone beds andscreens between pillow lavas yield Turonian to Santonian–Campa-nian microfauna (Khalatbari-Jafari et al., 2003). Volcano-sedimen-tary rocks in the upper member of the supra-ophiolitic turbiditescontain Late Cretaceous–Early Paleocene microfossils (Fig. 12B).Recently Azizi et al. (2011) reported U–Pb zircon ages of 566–596 Ma for eastern metamorphic complex gneissic granite and550 Ma for amphibolite. This shows that the K–Ar ages ofKhalatbari-Jafari et al. (2003, 2004) are reset. We suggest thatthe Khoy eastern metamorphic complex is Cadomian crust of theCentral Iranian block margin, not part of a Mesozoic meta-ophiolite.

Ar–Ar dating results on dioritic dike/volcanic rocks from theHassanbag ophiolites (Iraqi Zagros) (Ali et al., 2012) give Albian–Cenomanian (106–92 Ma) ages. These mid-Cretaceous ages over-lap some Khoy younger ophiolite ages and also a zircon U–Pb ageon the Kermanshah ophiolite (98 Ma Ma; Shafaii Moghadamet al., unpublished data). Ar–Ar ages on Haji Abad blueschists showthat these were metamorphosed �95–85 Ma (Agard et al., 2006).The need for careful U–Pb zircon geochronology on outer Zagrosophiolites is demonstrated by the fact that pelagic sediments cov-ering the ophiolites give slightly older ages; � 99–97 Ma. In con-trast, some ophiolites along the Iran–Iraq border have Eocene (42and 37 Ma) U–Pb zircon ages (Shafaii Moghadam et al., unpub-lished data; Rahimzadeh, pers. comm.). Felsic dikes from Triassicpassive margin-type Kermanshah ophiolites yield U–Pb zirconage of 220 Ma (with abundant inherited ages at 800 and2200 Ma) (Shafaii Moghadam et al., unpublished data).


U–Pb zircon TIMS ages are 103–101 Ma for Nain and 101–99 Ma for Dehshir ophiolites (Fig. 12A) (Shafaii Moghadam et al.,2013c), apparently older than outer Zagros ophiolites and moreconsistent with biostratigraphic ages of overlying sedimentarysequences, which range from Cenomanian to Maastrichtian. Gab-bro and plagiogranite from the Balvard–Baft ophiolites have con-cordant ages of 103.2 ± 2.4 Ma, but most grains are inheritedEarly Palaeozoic (Ordovician) xenocrysts (Shafaii Moghadamet al., unpublished data).


Zircon and titanite U–Pb geochronology on felsic segregationsin STOB mafic granulites yield ages of 107.4 ± 2.4 and105.9 ± 2.3 Ma (Albian), respectively (Fig. 12A; Rossetti et al.,2010). A SHRIMP U–Pb zircon age of 99.32 ± 0.72 Ma is interpreted

Pelagic sediments

A) Mesozoic Sabzevar, Outer and Inner Belts Zagros Ophiolites

130 Ma

110 Ma

90 Ma

70 Ma

50 Ma

Early Cretaceous

Albian

Late Cretaceous

Paleocene

Sabz

evar

-To

rbat

& turbidites

Felsic segregationsin metamorphic rocks

Birja

nd-

Neh

band

anRadiolarites

Pelagic limestone

Rb-Sr

high-P blueschists& eclogites

Leucogabbro

U-Pb zirconeclogite & acidic rocks

Khoy

-Mak

u

160 Ma

130 Ma

100 Ma

70 Ma

50 Ma

Late Jurassic

Early Cretaceous

Late Cretaceous

Early Paleogene

B) Mesozoic Makran, Khoy-Maku and Birjand Ophiolites

Inne

r Mak

ran

Out

er M

akra

n

Limestonesfrom Ganj complex

++

+++K-Ar, gabbro

K-Ar, dike

Ganj complex

+ gabbroBand-e-Zeyarat

Mokhtarabadradiolarites

Mok

htar

abad

Radiolarites interbeddedwith pillow lavas

Pelagic limestones

Kahn

uj

++++

K-Ar, amph.Gabbroic rocks

+K-Ar, granites

+

+

++

Band-e-Zeyaratgabbros, Ar-Ar

Plagiogranite

+ U-Pbtrondhjemite

+

gran

itic

dike

TIMS

TIMS

SHRIMP

limes

tone

+

+

Pillow lavaophiolite

K-Ar (plag)

K-Ar (plag)Gabbro

Turbidites

Volcano-sedimentaryrocks

Pillow lava

Supra-ophioliticturbidites

~

+

+

+

+

+

+

Plag

iogr

anite

+++dioritic dike,

Has

anba

g-Ke

rman

shah

volcanic rock

+diabasic dike

+++ +

+++

Ney

riz-

Haj

i Aba

d

high-P blueschists

plagiogranite

gabb

ro

Nai

n

Deh

shir

Balv

ard-

Baft

+ + +plagiogranite

plagiogranitediorite-gabbro

+

+

+

+

++

+++

K-Ar agesU-Pb zirconAr-Ar agesBiostratigraphical ages

Legend

Outer Zagros Ophiolites Inner Zagros Ophiolites

+ gabbro-plagiogranite

+

+

30 Ma

+

plag

iogr

anite

+plagiogranite

Eocene ophiolite

Eocene+

Fig. 12. Simplified chart showing the ages of magmatic and sedimentary sequences of the Mesozoic ophiolites. Ar–Ar age data on the Hasanbag ophiolites (Iraq) from Ali et al.(2012); K–Ar ages on the Kermanshah ophiolite from Delaloye and Desmons (1980); U–Pb zircon ages on the Kermanshah Late Cretaceous and Eocene ophiolites are fromShafaii Moghadam et al. (unpublished data); Ar–Ar ages on Neyriz plagiogranites are from Lanphere and Pamic (1983) and on Neyriz gabbros from (Babaei et al., 2006). Agesof high-pressure metamorphic rocks of the Haji Abad ophiolite is from Agard et al. (2006). K–Ar ages of inner belt Zagros ophiolites are from Shafaii Moghadam et al. (2009)and U–Pb zircon ages of the Nain and Dehshir ophiolites are from Shafaii Moghadam et al. (2013c). U–Pb zircon data on felsic segregations of the Sabzevar ophiolitemetamorphic rocks are from Rossetti et al. (2010), SHRIMP and TIMS U–Pb zircon ages of Sabzevar plagiogranites are from Shafaii Moghadam et al. (2014). U–Pb zircon agesof Birjand gabbroic rocks are from Zarrinkoub et al. (2012) and on the Birjand high pressure and felsic rocks from Brocker et al. (2010, 2013); K–Ar ages of Khoy–Makumagmatic rocks are from Khalatbari-Jafari et al. (2003, 2004), K–Ar ages of Inner Makran ophiolites are from McCall (1985); U–Pb zircon ages of Inner Makran magmatic rocksare from Hunziker et al. (2011), K–Ar ages on Kahnuj ophiolites are from Hassanipak et al. (1996) and Ar–Ar ages are from Ghazi et al. (2004).


as when Sabzevar ophiolite magmas crystallized (Fig. 12A) (ShafaiiMoghadam et al., 2014). SHRIMP and TIMS U–Pb zircon datingreveals an age of 96.7 ± 2.1 and 98.3 ± 0.16 Ma for the formationof the Torbat ophiolite (Shafaii Moghadam et al., 2014). Our U–Pb zircon dating and microfossil results (A. Taheri; personal com-munication) show that the Torbat-e-Heydarieh (SE part of STOB)and Sabzevar ophiolites (NW part of the STOB) are the same age.The paleontological ages vary from Campanian to Maastrichtianin the Sabzevar and Torbat-e-Heydarieh. Volcano-pelagic seriesof the Oryan zone also include Cenomanian to Maastrichtian pela-gic sediments that are interbedded with pyroclastic and andesiticto dacitic lavas. TIMS U–Pb zircon ages of STOB plagiogranitesyields ages that variy from 99.92 ± 0.12 to 77.82 ± 0.28 Ma, compa-rable with U–Pb zircon ages on the Arghash–Ali Abad plutonicrocks (between Sabzevar ophiolite in the north and Cheshmeshirophiolite in the south). Arghash pluons were emplaced from

Cenomanian–Maastrichtian (97.0 ± 0.2 Ma; 92.8 ± 1.3 Ma) toOligo-Miocene (29.8 ± 0.2 Ma) time (Shafaii Moghadam et al.,unpublished data; Alaminia et al., 2013). Although younger tec-tonic phases have influenced the Sabzevar region, intrusive con-tacts between the old granitic–dioritic plutons (e.g. Arghash andAli-Abad plutons) show no major tectonic phases since Late Creta-ceous time that could be the force for displacing a single coherentslab of Sabzevar oceanic lithosphere. These ages are similar tothose obtained from the inner Zagros ophiolites, but clearly a lotmore work is needed before we understand when this ophiolitebelt formed.


Brocker et al. (2013) obtained Rb–Sr isochron ages of ca.87–83 Ma for high pressure metamorphic rocks from the


Birjand–Nehbandan. SHRIMP U–Pb zircon dating of metafelsicrocks and eclogites also gave ages of ca. 86–89 Ma (Fig. 12B). Basedon these data, they concluded that Late Cretaceous subduction andcollision formed the Sistan Suture. However these ages are signif-icantly younger than those reported for the crystallization of Birj-and ophiolite gabbroic rocks by Zarrinkoub et al. (2012) (ca. 113–107 Ma; LA-ICP-MS technique) which agree with biostratigraphicages on the pelagic limestones (Tirrul et al., 1983) (Fig. 12B) butare younger than Early Aptian–middle Late Albian ages for radiol-arites (Babazadeh and De Wever, 2004; Babazade, 2007).

4.5. Makran ophiolites

There is limited geochronological data for Makran ophiolites.Associated pelagic sediments contain Jurassic to Early Paleocenemicrofauna in the inner Makran ophiolites (McCall, 1997). Ganjcomplex gabbroic rocks yield Aptian–Albian K–Ar ages whereasdikes have Cenomanian ages (McCall, 1985). K–Ar dating ofBand-e-Zeyarat gabbros yields an age of 120 Ma (McCall, 1985).U–Pb zircon ages of trondhjemite and granitic dikes from theRameshk ophiolite are 145 and 111 Ma, respectively (Hunzikeret al., 2011). Biomicrite intercalated with outer Makran ophiolitepillow lavas are dominated by Campanian–Maastrichtian microfa-unas, although there are also Cenomanian, Turonian, Coniacian andSantonian microfossils (McCall, 2002). The radiolarites associatedwith pillow lavas and pelagic limestones range from Pliensbachian(Jurassic) to Coniacian (Fig. 12B).

Pelagic limestones in the Dare Anar complex of the Kahnujophiolite contain microfaunas of Aptian–Cenomanian age (Arvinet al., 2001). Most K–Ar ages from gabbros and dikes of the Kahnujophiolite range between 156 and 136 Ma or 144–139 Ma(Kananian et al., 2001). K–Ar ages for amphibole from dioritic rocksare �125 Ma, while younger ages of 93–89 Ma are from potassicgranites (Kananian et al., 2001). K–Ar (Hassanipak et al., 1996)and Ar–Ar (Ghazi et al., 2004) ages of amphibole separates fromBand-e-Zeyarat high-level gabbros range from 124 ± 4 to146 ± 2 Ma and 142.9 ± 3.5 to 140.7 ± 2.2 Ma respectively.

5. Summary of compositional variations in Iranian Mesozoicophiolites

In this section we synthesize geochemical information for Ira-nian Mesozoic ophiolites. The datasets we integrate in this sectionare whole rock trace element data and chemical composition ofindicator minerals especially Cr# (=100 atomic Cr/Cr + Al) spinelin peridotite. Tables 1 and 2 also summarize the most importantcompositional features of these ophiolites.

5.1. Khoy–Maku and Zagros outer belt ophiolites

Khoy ophiolite mantle peridotites are mostly fertile lherzoliteswith low Cr# spinels (Cr# 16–21; Monsef et al., 2010) similar tothose of abyssal peridotites (Fig. 13A), although some high Cr# spi-nels (�31–60; Monsef et al., 2010) plot in the compositional rangebetween abyssal and SSZ peridotites (Monsef et al., 2010). Makuperidotites have Al-rich spinels (Cr# 19) resembling those of abys-sal peridotites (Rezai et al., 2010). The Zagros ophiolites includingLate Cretaceous Kermanshah, Neyriz and Haji-Abad ophiolites havespinels like those of forearc peridotites (Fig. 13A).

Basaltic fragments in basal breccias of the Khoy supra-ophioliteturbidites show T-MORB to calc-alkaline geochemical affinitieswhereas pillow lavas (in the upper parts of the turbidite section)show IAT to calc-alkaline characteristics (Khalatbari-Jafari et al.,2003, 2004). Maku ophiolite basalts include massive to pillowedlavas with calc-alkaline and/or OIB-type alkaline geochemical

affinities (Poor Mohsen et al., 2010). Mostly OIB-type (but somecalc-alkaline) basaltic dikes and sills crosscut the Maku pillow lavasequences. Basaltic calc-alkaline/OIB-type sills and dikes alsocrosscut the overlying turbidites. Basaltic fragments within theturbidites show mostly calc-alkaline characteristics but OIB-typefragments also are common (Fig. 14A). Compared to the Khoy ophi-olite, the Maku ophiolite is mostly characterized by OIB-type alka-line lavas with more calc-alkaline lava fragments as breccias.

Zagros outer belt ophiolitic basalts have E-MORB and rarely N-MORB geochemical signatures (Khalatbari-Jafari et al., 2003, 2004)(Fig. 14A). Khoy pillow lavas and most basaltic fragments in turbi-dites have low Th/Yb for a give Nb/Yb, similar to E-MORB and/or T-MORB (Fig. 14A). Such lavas may have formed by partial melting ofplume-contaminated depleted mantle beneath an oceanic spread-ing center (Khalatbari-Jafari et al., 2006) or from subontinentallithospheric mantle. The exceptions are some basaltic fragmentswithin the turbidites with calc-alkaline characteristics and lowerTi and Nb abundances. Some lavas have higher Th and lower Nband Ti contents (Fig. 14A), resembling SSZ lavas. Most Kermanshahlavas have calc-alkaline signatures and plot in the Oman V1 lavafield on Ti vs. V diagram (Fig. 14B). Island-arc tholeiitic lavas areminor components. The Harsin–Sahneh ophiolitic associated dikesthat intrude harzburgites or gabbros are thought to have a back-arcbasin basalt (BABB) signature (Whitechurch et al., 2013). Haji Abadophiolite lavas can be divided into E-MORB-like (or OIB-like), calc-alkaline and boninitic pillow lavas (Shafaii Moghadam et al., 2012).Haji Abad E-MORB-like lavas are enriched in Nb–Ti and may haveformed during subduction initiation (Shafaii Moghadam and Stern,2011) from a mantle source uncontaminated by slab-derived flu-ids. Haji Abad boninitic lavas resemble Oman V2 lavas and Izu–Bonin–Mariana (IBM) boninites. Most Neyriz ophiolite lavas areslightly depleted in Nb and enriched in Th but some of them aresimilar to early arc tholeiites of the IBM forearc (Fig. 14A). The Ker-manshah Triassic–Cretaceous lavas and gabbros related to the pas-sive margin-type ophiolites have OIB- and E-MORB-like signatures(Fig. 14A) suggesting origin from low-degree partial melting ofplume-contaminated mantle (Saccani et al., 2013). However thelavas and gabbros from Kurdistan Eocene ophiolites have E-MORBand P-MORB geochemical signatures and are geochemically similarto Khoy-Maku lavas (Saccani et al., 2014).


Most inner Zagros peridotite spinel Cr#s are like those of SSZperidotites (Cr# > 40) except some plagioclase-bearing (impreg-nated) lherzolites from the Nain and Dehshir ophiolites(Fig. 13B). The SSZ signature increases from Nain toward the Bal-vard–Baft ophiolites. Nearly all inner Zagros ophiolitic lavas havecalc-alkaline and island-arc tholeiitic signatures (IAT) and MORBrocks are rare (Shafaii Moghadam and Stern, 2011). The SSZ signa-ture is conspicuous in Th/Yb vs. Nb/Yb diagram; nearly all mag-matic rocks are characterized by high Th/Yb, similar to Oman V2lavas and IBM boninites and forearc basalts (Fig. 14C). The SSZ sig-nature of the inner Zagros ophiolites is stronger than in outerZagros ophiolites. This may reflect proximity to the magmaticarc, with higher sediment melt/fluid input into the mantle wedgesource of inner Zagros ophiolite lavas.


Our geochemical data indicates that nearly all STOB lavas haveSSZ geochemical signatures and that MORB-type lavas are absent(Shafaii Moghadam et al., 2014). Mantle rocks also show SSZ signa-tures, as shown by spinel and pyroxene compositions. Sabzevarperidotite (Sabzevar, Forumad and Gaft) spinels have elevatedCr# (>40). The exceptions are impregnated peridotites in the

0

50

100

Cr#

(100

Cr/C

r+Al

)

Mg# (100Mg/Mg+Fe)

Boninite

Forearc peridotite

Back-arc peridotite

Abyssalperidotite

0

50

100

Cr#

(100

Cr/C

r+Al

)

Mg# (100Mg/Mg+Fe)

Boninite

Forearc peridotite

Back-arc peridotite

Abyssalperidotite

0

50

100

Cr#

(100

Cr/C

r+Al

)

Mg# (100Mg/Mg+Fe)

Boninite

Forearc peridotite

Back-arc peridotite

Abyssalperidotite

0

50

100C

r# (1

00C

r/Cr+

Al)

Mg# (100Mg/Mg+Fe)

Boninite

Forearc peridotite

Back-arc peridotite

Abyssalperidotite

A B

C D

Kermanshah late K oph.Neyriz ophioliteHaji-Abad ophiolite

Kurdistan ophiolite

Penjwin oph.

Dehshir ophioliteShahr-e-Babak oph.Balvard-Baft ophiolite

Nain ophiolite

Maku oph.

OmanKhoy ophiolite

Sabzevar ophiolite

Torbat-e-Heydarieh oph.Makran ophiolite (Rudan)

Birjand-Nehbandan oph.

100 50 0 100 50 0

100 50 0 100 50 0

Fig. 13. Composition of peridotite spinels in Iranian Mesozoic ophiolites. Data on the Haji Abad peridotite spinels from Shafaii Moghadam et al. (2012b) and on theKermanshah, Neyriz, Nain, Shahr-e-Babak, Sabzevar and Torbat-e-Heydarieh ophiolites from Shafaii Moghadam et al. (unpublished data). Data on the Dehshir peridotitespinels from Shafaii Moghadam et al. (2010), on Baft ophiolites from Shafaii Moghadam et al. (2013a). Data from Shafaii Moghadam et al. (unpublished data) on the Birjandperidotites and from Saccani et al. (2010) for the Nehbandan ophiolites. Data from Khalatbari-Jafari et al. (2006) and Monsef et al. (2010) on the Khoy peridotites; data on theMaku peridotites from Rezai et al. (2010).


central Sabzevar belt that were generated due to percolation ofMORB-type melts (Fig. 13C). Torbat-e-Heydarieh peridotite spinelsare mostly Al-rich with low Cr# similar to back-arc basin and/orabyssal peridotites (Fig. 13C).

Whole rock major and trace element data from the Sabzevarophiolite indicate that most lavas have IAT and calc-alkalineaffinities (Fig. 14E and F). MORB lavas are rare. All of the gabbroicrocks (orthopyroxene + clinopyroxene + plagioclase ± olivine ±amphibole cumulates) and some late plagiogranitic dikes andintrusions have boninitic affinities. OIB-type (alkaline) lavas occurboth as fragments within agglomerates and breccias of Late Creta-ceous–Paleocene age (Baroz and Macaudiere, 1984) and in a pillowlava sequence near the Baghjar–Aliak villages. These agglomeratesand pillow lavas are respectively interbedded with or are overlainby Late Cretaceous pink limestone. These late OIB-type lavas aresimilar to Late Cretaceous OIB-type dikes intruding ophiolites inthe Tauride belt of Turkey (Çelik and Delaloye, 2003; Parlaket al., 2006) and Late Cretaceous Salahi volcanics of the Oman

ophiolite (Alabaster et al., 1982). The occurrence of these types oflavas may be the result of late-stage off-axis magmatism fed bymelts from an asthenospheric window formed by slab break-off,shortly after ophiolite emplacement (Shervais, 2001).

We do not have any isotopic age, mineral chemical or geochem-ical data for the Oryan–Bardaskan and Neyshabour ophiolites, norare there any paleontological ages.

Most Torbat-e-Heydarieh magmatic rocks have IAT affinity, butMORB-type lavas are also common. In Th/Yb vs. Nb/Yb and V vs. Tidiagrams, the Torbat lavas can be subdivided into two types; (1)samples with higher Th/Yb but lower Ti content resembling arctholeiites and Oman V2 lavas and (2) samples with lower Th/Ybbut higher Ti content, similar to MORB (Fig. 14E and F).


The tectonic affinities of Nehbandhan and Birjand ophioliticcrustal rocks differ. Lavas with SSZ affinities dominate the Birjand


ophiolite whereas Nehbandan lavas show N-MORB and E-MORBcharacteristics. Peridotites show the opposite: Birjand peridotitesare mostly MORB-like whereas Nehbandan mantle tectonites exhi-bit both MORB-like and SSZ-affinities (Delavari et al., 2009). Neh-bandan MORB-type mantle rocks include Cpx-rich harzburgiteswith low Cr# (15–21) spinels whereas more depleted peridotiteshave higher Cr# spinels (33.5–37) and Birjand ophiolite mantleperidotites contain mostly MORB-like spinels (Fig. 14D). Nehban-dan ophiolite basalts comprise both enriched (E-MORB) anddepleted (N-MORB) varieties (Saccani et al., 2010). MORB-like mas-sive lavas and OIB-like pillow lavas are subordinate (Zarrinkoubet al., 2012). MORB and OIB samples may represent magmas gen-erated in an oceanic island (Zarrinkoub et al., 2012). Other Nehban-dan samples including lavas, diabasic dikes within mantle sectionsand gabbroic rocks have high Th/Yb and low Nb/Yb ratios resem-bling SSZ lavas (Fig. 14G).

More attention is needed to highlight the spatial and temporalrelationships between E-MORB and N-MORB lavas and SSZ-typesections in the Birjand and Nehbandan ophiolites. This will allowus to better understand if the enriched lavas are part of the ophio-lite or formed later, perhaps accompanying ophiolite emplacement.

5.5. Makran ophiolites

There are no geochemical data for outer Makran ophiolites,except some spinel compositions from Rudan and Sorkhband ultra-mafic rocks. These data show that peridotite spinels are SSZ-likewhile chromitites have high Cr# resembling those of boninites(Fig. 13D). Ghazi et al. (2004) concluded from REE and trace ele-ment patterns that Band-e-Zeyarat gabbros and trondhjemitesand Dare Anar complex lavas are E-MORB. T-MORB-like andback-arc basin basalt-like geochemical affinities are inferred forDare Anar lavas and Band-e-Zeyarat gabbros (Arvin et al., 2001;Arvin et al., 2005), who inferred a SSZ environment for Kahnujophiolite formation.

Band-e-Zeyarat gabbros (both deep cumulates and high-levelisotropic gabbros) are characterized by high Th/Yb and low Nb/Yb similar to IAT, except for two samples that plot near E-MORB(Fig. 14G). Based on the geochemistry of Band-e-Zeyarat gabbroicrocks, a mid-oceanic ridge environment is suggested for formationof the Kahnuj ophiolite (Arvin et al., 2005). Geochemical data forKahnuj and Ganj ophiolite lavas mostly show MORB signatures,similar to Oman V1 lavas, although some have higher Th/Yb, sim-ilar to IAT. The relationship between lavas and gabbros with higherand lower Th/Yb is not clear and we do not yet understand if thereare anysystematic chemotemporal changes in Kahnuj ophiolitelavas.

6. Discussion

Below we discuss three aspects of Iranian Mesozoic ophiolites:(1) how similar and different these are to other Tethyan ophiolitesof similar age; (2) their petrological diversity; and (3) what theytell us about the tectonic evolution of the region.

6.1. Comparison with other Mesozoic Tethyan ophiolites

6.1.1. Comparison with Jurassic ophiolitesThere is the puzzle of the Jurassic ophiolites of Iran, what do

these indicate? Jurassic–Cretaceous ophiolites are distributed inSE Iran and SW Pakistan, north of the Makran subduction zone.They include Kahnuj and inner and outer Makran ophiolites, anophiolite belt that continues eastward into S–SW Pakistan (Baluch-istan) Jurassic–Cretaceous ophiolites, including Muslim Bagh(Khan et al. 2007), Bela (Zaigham and Mallick, 2000) and Ras Koh

ophiolites (Siddiqui et al. 2012). The oldest rock unit in the RasKoh arc is the Jurassic Ras Koh accretionary complex. Late Creta-ceous volcanic rocks of the Ras Koh magmatic belt show IAT signa-tures suggesting that this was an intraoceanic arc. Ras Koh arc ispart of the magmatic arc stretching from Zagros to Waziristan(Siddiqui et al., 2012).

Jurassic ophiolites may also exist in NW Iran. Ophiolites alongthe Ankara–Erzincan (NE Turkey)–Sevan (Armenia) suture zone(at the boundary with NW Iran), including Refahiye, Sahvelet,Karadag, Kirdag (Turkey) and Sevan, Stepanavan, Vedi and Amasia(Armenia), have Lower–Middle Jurassic to Early Cretaceous Ar–Arages of ca. 176–169, 170–150 and 117 Ma (e.g., Çelik et al., 2011;Galoyan et al., 2009; Rolland et al., 2009a, 2010; Hassig et al.,2013). Because the K–Ar ages of Khalatbari-Jafari et al. (2003,2004) are ambiguous, we are unsure about the presence or absenceof Jurassic ophiolites in NW Iran and U–Pb zircon ages are neededto resolve this issue. Lesser Caucasus ophiolites include lavas andgabbros with MORB, OIB and arc signatures (e.g., Galoyan et al.,2009; Rolland et al., 2009b; Hassig et al., 2013). OIB magmatism(ca. 117 Ma) is younger than MORB-type magmatism (170–150 Ma) and OIB lavas erupted on the top of ophiolites. Early Cre-taceous OIB seems to have issued from a mantle plume sourceprior to Late Cretaceous (Coniacian–Santonian) ophiolite obduc-tion (Rolland et al., 2009b; Hassig et al., 2013).

6.1.2. Comparison with Late Cretaceous ophiolitesMost Iranian Neotethyan ophiolites have Late Cretaceous ages.

Brocker et al. (2013) recently documented the importance of LateCretaceous subduction processes for the geodynamic evolution ofthe Birjand ophiolite, although gabbro crystallization agess are asold as late Early Cretaceous. Late Cretaceous Tethyan ophiolitessouth of the Tauride platform of Turkey and the Central IranianBlock were emplaced onto the northern edge of Arabia, includingTroodos (Cyprus), Kizildag (Turkey), Baer-Bassit (Syria) and Zagros(Dilek and Thy, 2009). All these Late Cretaceous Neotethyan ophi-olites are about the same age; 90–94 Ma for Troodos plagiogranite(U–Pb zircon; Mukasa and Ludden, 1987); 95 Ma for Oman plagi-ogranite (U–Pb zircon; Hacker et al., 1996); 91–92 Ma for Kizildagplagiogranite (U–Pb zircon; Dilek and Thy, 2009); 92–93 Ma forOuter belt Neyriz hornblende gabbros (40Ar–39Ar; Babaei et al.,2006); 103–99 Ma for Inner belt plagiogranites and diorites (U–Pb zircon; Shafaii Moghadam et al., 2013c); and 100–78 Ma forSabzevar–Torbat plagiogranites and 101–77 Ma on Khoy gabbros(Khalatbari-Jafari et al., 2006). These ages differ from those of Mak-ran (U–Pb zircon; 145–111 Ma)–Kahnuj (Ar–Ar; 143–141 Ma) andBirjand (U–Pb zircon on felsic rocks; 89–86 Ma and on gabbros;113–107 Ma) ophiolites.

Late Cretaceous Neotethyan ophiolites of Troodos and Oman arebetter studied than any ophiolite in Iran and provide very usefulperspectives. The Troodos ophiolite crustal sequence containslower pillow lavas with IAT signature while upper lavas are bonin-itic (Thy and Xenophontos, 1991; Dilek and Thy, 2009; Osozawaet al., 2012). Kizildag ophiolite (Turkey) shows geochemical evolu-tion from MORB to boninite (Bagci et al., 2008; Dilek and Thy,2009). Chemostratigraphy for Oman lavas shows that these lavaschange from MORB-like (Geotimes or V1 unit) upwards intodepleted IAT and boninitic (Lasail and V2 unit) (Alabaster et al.,1982; Ernewein et al., 1988). Our compiled data indicates thatmost Iranian ophiolites are similar to other Late Cretaceous Teth-yan ophiolites in terms of age and geochemical signatures,although OIB-like lavas are more abundant in Iran than elsewhere.

6.1.3. Importance of Eocene ophiolitesEocene and younger ophiolites exist in Indonesia (Ishikawa

et al., 2007; Kaneko et al., 2007), Philippines (Yumul, 2007), Taiwan(Jahn, 1986), Japan (Hirano et al., 2003) and also in Chile (Veloso


et al., 2005; Anma et al., 2006) but are rare in the Tethyan realm ofSW Asia. Occurrence of dike swarms (with Eocene U–Pb age) andSSZ-type lavas in Kermanshah and Kurdistan show that the south-ern Neotethyan Ocean was open and magmatism was active untilat least Late Eocene and may reflect a phase of back-arc rifting. Cer-tainly more work is needed to understand the significance ofEocene ophiolitic suites in Iran.

6.2. Petrological diversity of Iranian Mesozoic ophiolites

Mesozoic ophiolites in the Alpine–Zagros–Himalayan belt havedifferent origins (continental margin, mid-ocean ridge, and SSZ

0.1 1 10 1000.01

0.1

1

10

100

MORB-OIB array

volcanic arc array

Kermanshah Late K. ophiolite

N-MORB

E-MORB

OIB

Haji-abad ophioliteNeyriz ophiolite

Oman V2 lavas

0.1 1 10 1000.01

0.1

1

10

100

MORB-OIB array

volcanic arc array

Th/Y

b

Nain ophioliteN-MORB

E-MORB

OIB

Dehshir ophiolite

Oman V2 lavas

0.1 1 10 1000.01

0.1

1

10

MORB-OIB array

volcanic arc array

Sabzevar ophiolites

N-MORB

E-MORB

OIB

Torbat-e-Heydarieh ophiolite

Oman V2 lavas

Nb/Yb

0.01

0.1

1

10

100

MORB-OIB array

volcanic arc array

N-MORB

E-MORB

OIBOman V2 lavas

Birjand ophiolite (this study)Birjand ophiolite (Z. et al.,)

0.1 1 10 100

IBM forearc lavas

A

C

E

GKahnuj lavas (Arvin et al., 2001)

Ganj lavas (Shaker Ardakani et al., 2009)

Maku ophiolite (PoorMohsen et al.,)2010

Fig. 14. Trace element compositional variations (Th/Yb vs. Nb/Yb and Ti vs. V) of Iran M(2008) and Ti vs. V diagram modified after Shervais (1982). Data for the Haji Abad ophiolShahr-e-Babak and Torbat-e-Heydarieh ophiolites are from Shafaii Moghadam et al. (un(2010), for Baft ophiolites from Shafaii Moghadam et al. (2013a) and for Sabzevar ophioliMoghadam et al. (unpublished data) and Zarrinkoub et al. (2012); data on the NehbandaJafari et al. (2006) and on the Maku ophiolite from Poor Mohsen et al. (2010). Data on thefrom Ghazi et al. (2004) and data on the Ganj complex from Shaker Ardakani et al. (200

types) but all are related to the opening and closure of Neotethys(Furnes et al., 2014 and references therein). They are principallyof two ages; an older group around 170–140 Ma (Betic, Chenaillet,Zermatt-Saas, External and Internal Ligurides, Calabrian, Corsica,Mirdita, Pindos, Eldivan, Refahiye, Sevan, Makran, Muslim Bagh,Saga, Sangsang) and a younger group around 125–90 Ma (Troodos,Kizildag, Oman, Outer and Inner Zagros belts, Birjand–Nehbandan,Sabzevar–Torbat-e-Heydarieh, Muslim Bagh, Waziristan, plus mostof the examples of the Yarlung–Zangbo Suture Zone) (Furnes et al.,2014). The older group dominates in Europe and the younger groupdominates in Asia. The various types of Neotethys ophiolites andhow Iranian ophiolites relate to these are discussed further below.

0 5 10 15 20 25 300

200

400

600

OIB

MORB

IAT

Boni

nite

0 5 10 15 20 25 300

200

400

600

V (p

pm)

OIB

MORB

IATBo

nini

te

Balvard-Baft ophiolite

Shahr-e-Babak ophiolite

0 5 10 15 20 25 300

200

400 OIB

MORB

IAT

Boni

nite

Ti (ppm)/1000

0 5 10 15 20 25 300

200

400

600

OIB

MORB

IAT

Boni

nite

Nehbandan ophiolite (Saccani et al.,)2010

Oman V1 lavas

B

D

F

H

Kahnuj gabbrosGhazi et al., 2004Kahnuj lavasGhazi et al., 2004

Khoy supra-ophiolitic rocksKhalatbary jafari et al., 2006Khoy volcanic rocksKhalatbary jafari et al., 2006

Eocene Kurdistan oph. (S et al.)

esozoic ophiolitic magmatic rocks. Th/Yb vs. Nb/Yb diagram modified after Pearceites are from Shafaii Moghadam et al. (2012b) and for the Kermanshah, Neyriz, Nain,published data). Data for the Dehshir ophiolites are from Shafaii Moghadam et al.

tes from Shafaii Moghadam et al., (2014). Data on the Birjand ophiolites from Shafaiin ophiolites from Saccani et al. (2010). Data on the Khoy ophiolite from Khalatbari-Kahnuj ophiolite lavas from Arvin et al. (2001); data on the Kahnuj gabbros and lavas9).


6.2.1. Passive continental margin-type ophiolitesThis type of ophiolite is related to early rifting of northern

Gondwana during Late Permian–Triassic time to open Neotethys.These ophiolites have Triassic-Jurassic (to early Cretaceous) agesand fragments of this activity are found in Kurdistan, Kermanshah(Bisotun limestone and Kermanshah radiolarite), Neyriz (themélange associated with Pichakun complex) and Oman (Hawasinacomplex) (Table 1). Our U–Pb dating from Kermanshah plagiogra-nites reveals an age of 222.1 ± 3.8 Ma for the extension of TethyanOcean (unpublished data). Igneous rocks in these ophiolites haveOIB (alkaline) and E-MORB signatures (with Nb–Ta and withoutTh enrichment) and are often associated with fertile lherzolite, per-haps subcontinental mantle. This led Sacanni et al. (2013) to con-sider a passive margion origin for the Triassic–JurassicKermanshah ophiolites. However, a subcontinental origin for thesefertile meta-lherzolites is not well explained, as spinel Cr# fromthese lherzolites is not so low (�25–29). Alpine subcontinentallherzolite is characterized by spinel with very low Cr# (<10),high-Al Opx, and high Al, high Na Cpx, as well as association withgarnet-spinel pyroxenite (e.g., Ishiwatari, 1985; Muntener et al.,2010). Garnet pyroxenite is missing from Kermanshah Triassicophiolites.

6.2.2. MORB-type ophiolitesOphiolites with only MORB-type igneous rocks are rare because

they form on the downgoing oceanic plate, which is hard to obduct.Such ophiolites are also rare in Iran. The best example is the LateCretaceous Khoy–Maku ophiolite, which has E-MORB, N-MORBand OIB-type igneous rocks (Fig. 14). These igneous rocks generallylack Nb–Ta depletions. However even in this ophiolite the MORBsgrade upward into calc-alkaline and arc tholeiites and/or late SSZ-type dikes crosscut the early MORB sequences. This shows a tran-sition from a MORB-type setting to supra-subduction zone mag-matism during Late Cretaceoues–Early Paleocene time. TheNehbandan (and some Birjand) rocks in the Birjand–Nehbandanophiolitic belt also show MORB signatures but the occurrence ofSSZ-type lavas and peridotites and exhumed eclogites and blues-chists indicate a supra-subduction zone setting for these ophio-lites. It seems that early eruption of MORB- (N-MORB & E-MORB)and OIB-like lavas (ca.113–107 Ma) was followed by Late Creta-ceous (ca. 100–80 Ma) intraoceanic subduction and eruption ofSSZ-related lavas, gabbros and depleted mantle harzburgites. Thisis analoguous to the chemostratigraphy identified for ‘‘subduc-tion-initiation rule ophiolites’’ by Whattam and Stern (2011).

6.2.3. Plume-type ophiolitesThe Maku ophiolite in NW Iran is characterized by OIB-type and

ankaramitic pillow lavas and OIB-like dikes that are similar toplume-type ophiolites of Dilek and Furnes (2011), althoughMORB-like and SSZ-like lavas are also common in the Khoyophiolites.

6.2.4. Supra-subduction zone-type ophiolitesMost Iranian ophiolitic rocks – from mantle peridotites to over-

lying lavas – have geochemical signatures resembling magmas andresidues generated over subduction zones, including arcs, backarcbasins and forearcs. SSZ magmatism was very common in formingboth outer and inner Zagros ophiolite belts. Mantle peridotites ofthese have spinels mostly with Cr#>40. Most magmatic rocks fromthese ophiolites have Nb–Ta depletion and Th (and LILEs) enrich-ment, consistent with magmatism above a convergent margin.

Most Sabzevar ophiolitic magmatic rocks are also SSZ-type,with Nb–Ta depletion (Fig. 14). This is also true for Torbat-e-Hey-darieh lavas, which were also influenced by slab-derived compo-nents, testified by higher Th/Yb ratios, but peridotite spinels havelower Cr#, similar to back-arc basin peridotite spinels.

6.2.5. Volcanic arc-type ophiolitesVolcanic arc-type ophiolites typically have longer lifespans than

other ophiolite types, sometimes >20–30 Ma (Dilek and Furnes,2011). Many more U–Pb zircon ages are needed for Iranian ophio-lites, but available data indicate that most were magmaticallyactive for less than 10 Ma, except the Sabzevar–Torbat-e-Heyda-rieh ophiolites with >20 Ma life. The presence of the intra-oceanicfelsic arc within the Sabzevar basin with ages similar to Sabzevarplagiogranites (�98 Ma) is another line of evidence showing thatthe Sabzevar ophiolites resemble volcanic-arc type ophiolites ofDilek and Furnes (2011). Kurdistan Eocene ophiolites have also vol-canic-arc type ophiolite characteristics.

6.2.6. Accretionary prism-type ophiolitesAlthough the Makran ophiolites (including Kahnuj) have both

MORB- and SSZ-type magmatic rocks and their tectono-magmaticsetting is similar to that of back-arc basins, the presence of hugemasses of turbidites with oceanic lithosphere slices and the pres-ence of blueschists confirm that these ophiolites are similar toaccretionary prism-type ophiolites of Dilek and Furnes (2011).From geochemistry, it seems thatthe Makran ophiolites werederived from a mix of MORB and SSZ-type sources. An accretionaryprism scenario is also pertinent for Birjand–Nehbandan ophiolitesin eastern Iran.

6.3. Tectonic evolution of Iranian Mesozoic ophiolites

Iranian Neotethyan ophiolites are part of the Maghrebian–Alpine–Himalayan belt (referred to as the Alpides), which extendsfrom Morocco in the west, through the European Alps, the Anato-lides, Zagros, Makran, and the Himalayas in the east, defining anorogenic belt �9000 km long (Furnes et al., 2014). This orogenicbelt approximates the location of the Neotethys seaway. Neotethysbegan with Permian rifting of the northern margin of Gondwana,from which Cimmerian fragments drifted north and collided withEurasia to close Paleo-Tethys in Triassic time. Below we describebriefly the tectonic scenarios in which Iranian Mesozoic ophiolitesformed.

6.3.1. Zagros ophiolitesThere is broad agreement that Zagros ophiolites reflect the geo-

logic evolution of Neo-Tethys, from rifting to closure. Evidences forPermo-Triassic rifted margins include the presence of OIB-typegabbros and lavas; turbidites, deepwater radiolarites and platformcarbonates along with plume-related alkaline lavas within Ker-manshah radiolarites, Bisotun–Avroman limestones (Kerman-shah–Hasanbag), and Pichakun series (Neyriz). These Permo-Triassic volcano-sedimentary sequences correlate with the Hawa-sina complex of Oman.

Late Cretaceous events to form Zagros ophiolites (ZOB and ZIB)are controversial. According to some geologists, Neo-Tethyan oce-anic lithosphere was consumed in a NE-dipping subduction zonebeneath the Sananadaj–Sirjan zone (SNSZ) margin during EarlyJurassic time (Dercourt et al., 1986; Saccani et al., 2013). In thismodel, the Neyriz and other ZOB ophiolites are fragments ofNeo-Tethyan MORB oceanic lithosphere. The Kermanshah ophio-lite has been described as a piece of Tethyan oceanic lithospherescraped off during NE-directed subduction underneath the Iranianblock in Early Cretaceous time (e.g., Agard et al., 2005). An intra-oceanic arc origin has been suggested for the Eocene Kermanshahand Iranian–Iraqian Kurdistan ophiolites by Ghazi and Hassanipak(2000), Desmons and Beccaluva (1983) and Whitechurch et al.(2013). Our field, geochronological and geochemical data also con-firm that a younger intraoceanic arc or Eocene volcanic-arc typeophiolite is present in the Kermanshah–Kurdistan area (Fig 15).


ZOB ophiolites are distributed between older rocks of the SSNZ andMain Zagros Thrust (MZT) fault.

ZIB ophiolites have been described as originating from a Neo-Tethyan oceanic branch between the SSNZ and the Lut block(e.g., Berberian and King, 1981; Arvin and Robinson, 1994; Arvinand Shokri, 1997). In many interpretations the Nain-Baft ophiolitebelt represents a suture on the site of small Mesozoic ocean basin(e.g., Stampfli and Borel, 2002; Agard et al., 2006; ShafaiiMoghadam et al., 2009) surrounded by Cadomian microcontinents.However, evidence in support of this hypothesis, including evi-dence of rifted margins such as turbidites, deep water radiolaritesand platform carbonates along with rift-related alkaline lavas ismissing. Some geologists prefer a model whereby the IB marksthe position of a Campanian back-arc basin (e.g., Stampfli andBorel, 2002; Agard et al., 2006; Shafaii Moghadam et al., 2009).Such a back-arc basin could also have been a narrow seaway withdiscountinous oceanic crust (Shafaii Moghadam et al., 2009).

The other model for the genesis of Zagros ophiolites is the sub-duction initiation/infant-arc model, first applied to Zagros by

NNWCarbo

(A) Continental rifting, Neotethys opening and OIB-

GONDWANA

Arabia

LithosphereAsthenosphere

SSE SSE

CimmeriaArabia

(B) Neotethys accretion, mid-oceanic-ridge N-MORB magm

Neotethyan lithosphere

SSE

exhumed sub-continental mantlelherzolite

gabbro & dike

Arabia

seamount (OIB) N-

Late Triassic-Cretaceous Bisotun limestones;Kermanshah radiolarites & Pichakun series (Neyriz)

associated with Triassic OIB-type magmatism

(D) Intraoceanic arc (Kermanshah-Kurdistan) & Urumieh-Dokhtar magmatic arcEarly Paleocene-Late Eocene

Spreading (proto-forearc)

Arabia

Residual depleted (SSZ) harzburgite

OB

Arabia

SSZ-type ophiolites

Fig. 15. Schematic model for the formation and evolution of Zagros Mesozoic (and Cenozo(plume-related) lavas and gabbros in Late Permian-early Triassic (modified after Saccani eTriassic (modified after Saccani et al., 2013). (C) Intraoceanic subduction initiation in Latearc formation within Kermanshah–Kurdistan (Eocene ophiolites) and development of acblock.

Shafaii Moghadam and Stern (2011) (Fig. 15). In this model, theLate Cretaceous Zagros ophiolites along with Troodos and Omanophiolites constitute a long, broad, and continuous tract of oceaniclithosphere created at about the same time when subductionbegan along the southern margin of Eurasia. This subduction initi-ation event was accompanied by extension and infant arc igneousactivity, which initially occurred via seafloor spreading to form abroad ophiolitic forearc. This model infers that ZIB and ZOB wereonce part of a single ophiolitic forearc. Separate inner and outerZagros ophiolite belts formed later, when the forearc slab wasuplifted in Paleocene-Eocene time by exhumation of the partiallysubducted SSNZ, leading to erosion that separated ZIB and ZOBoutcrops.

This model is supported by strong SSZ affinities of most Zagrosophiolite igneous rocks, especially for the most diagnostic litholo-gies of mantle harzburgite, diabase dikes, and lavas, and by theobservation that early MORB-like lavas in some of these ophiolitesare succeeded by more arc-like lavas, a chemotemporal evolutionexpected for subduction-initiation ophiolites (Whattam and

NNWnate platform

type magmatism (Late Permian-early Triassic)

Plume-type components

OIB basalts

exhumed sub-continental mantle

OIB-type gabbros & dikes

Cimmeria

NNW

atism (Late Triassic)

& E-MORB magmatism

Cimmeria

Passive margin-type ophiolite

(C) Intraoceanic subduction initiation (Late Cretaceous)Iran

IB

Iran

Urumieh-Dokhtar magmatic arcEocene Kermanshah-Kurdistan& Iraq Zagros intraoceanic arc

Eocene ophiolites

ic) ophiolites. (A) Early phases of Neotethys opening with eruption of early OIB-typet al., 2013). (B) Neotethys accretion, mid-oceanic-ridge N-MORB magmatism in LateCretaceous and formation of proto-forearc and OB and IB ophiolites. (D) Intraoceanictive continental arc magmatism (Urumieh–Dokhtar magmatic belt) over the Iranian


Stern, 2011). The forearc/subduction inititiation model for Zagrosophiolites is most consistent with diagnostic lithologies, boniniteand harzburgite. A similar model has been applied to the Troodosand Semail ophiolites, by Whattam and Stern (2011), Pearce andRobinson (2010) and Osozawa et al. (2012). The geochemical datawe have summarized for both Late Cretaceous belts of Zagrosophiolites, plus the observation that some ZIB ophiolites areconformably overlain by arc-derived pyroclastic rocks compels usto conclude that both ZOB and ZIB formed over a nascentsubduction zone. This model predicts that ZIB and ZOB formed atthe same time, a prediction that needs to be tested with U–Pb zir-con geochronology. If confirmed, the excellent exposures of ophio-lites in the Troodos–Zagros–Semail ophiolite belt make it anexcellent natural laboratory for reconstructing how new subduc-tion zones form.

6.3.2. Khoy–Maku ophiolitesThe age and thus tectonic evolution of the Khoy–Maku ophio-

lites are controversial. As previously discussed, we consider thatthe older (eastern) metamorphic complex is part of the Central Ira-nian block margin, not a Mesozoic ophiolite. Microfossils showSantonian–Campanian to Early Paleocene ages for the young Khoyophiolites, somewhat younger than crystallization ages of the OBand IB Zagros ophiolites, so the relationship of the Khoy–Makuophiolite to Zagros ophiolites is not clear. One key concerns therelationship of the Khoy–Maku ophiolite to the poorly known ophi-olite belt that trends �North–South through Kurdistan along theIran–Iraq border north from Kermanshah to Khoy–Maku. TheKhoy–Maku ophiolites could represent a Late Cretaceous back-arc basin behind the Zagros ophiolites. This hypothesis is sup-ported by the occurence of E- to T-MORB pillow lavas in theKhoy–Maku ophiolite, which are crosscut by SSZ-type dikes andoverlain by turbidites with SSZ-type clasts. These lavas are geo-chemically similar to Eocene Kermanshah–Kurdistan ophiolites.More studies and especially U–Pb zircon dating is needed for thesemassifs as well as more studies of the ophiolites between the Khoyand Kermanshah regions.

6.3.3. Sabzevar–Torbat-e-Heydarieh ophiolitesThere are four key questions concerning Sabzevar–Tobat-e-

Heydarieh ophiolite belt (STOB); (1) is there any relationshipbetween the Zagros ophiolites (especially IB) and STOB? (2) Whattectonic environment did these ophiolites form in? (3) What is theage variation within STOB? (4) Did the various fragments of STOBoceanic lithosphere form about where they are today or are theyfar-traveled nappes? Our review provides some insights for thefirst three but not the last question.

Regarding the first question; it may be that STOB connects withZIB. Inspection of Fig. 2 shows a similarity of trends between Nainophiolite and STOB, but the intervening region is buried beneathyounger volcanics and sedimentsAeromagnetic and gravity sur-veys could help answer this question. There is similarity betweenthe ZIB and STOB ophiolites but ZOB ophiolites may be slightlyolder (ca. 103–99 Ma) than STOB (ca. 99–78 Ma).

Regarding the second question, nearly all STOB lavas have SSZgeochemical signatures (Shafaii Moghadam et al., 2014). Mantlerocks also show SSZ signatures, as shown by spinel and pyroxenecompositions. The STOB basin was somehow related to a conver-gent margin, perhaps forming as a back-arc basin behind theZagros convergent margin.

Regarding the third question, ophiolitic magmatism continuedfor �30 Ma, an unusually long life for an ophiolite. This suggeststhat STOB may be a volcanic arc ophiolite (Dilek and Furnes, 2011).

Taking into account all the geochemical, geochronological andpaleontologic evidence that we have for the STOB, we concludethat the Sabzevar Ocean was an arc-backarc basin complex

associated with an ocean basin that opened between the Lut Blockto the south and the Turan block to the north beginning no laterthan mid-Cretaceous time. Intraoceanic subduction began beforeAlbian time, testified by the age of felsic segregations in Sabzevarhigh-P metamorphic rocks (Fig. 16A). Subduction polarity wassouthwards, beneath the Lut block. Intraoceanic subduction wasresponsible for generating SSZ-related magmas within the Sabze-var oceanic lithosphere and formation of an arc between the Sab-zevar ophiolite in the north and Cheshmeshir–Torbat-e-Heydarieh ophiolites in the south during Late Cretaceous time. Inthis model, the Torbat-e-Heydarieh ophiolite formed as a back-arc basin. Evidence for oceanic lithosphere behind the matureand felsic arc comes from Oryan ophiolites. Clearly, the remarkableexpanse of STOB ophiolites invites more work.

6.3.4. Birjand–Nehbandan ophiolitesBirjand–Nehbandan ophiolites define the Sistan suture between

the Lut and Afghan continental blocks and their emplacementreflects the consumption of the �110 Ma Sistan Ocean followedby collision of the Lut and Afghan continental blocks. Early workersthought subduction polarity was toward the east, beneath theAfghan block (e.g., Camp and Griffis, 1982; Tirrul et al., 1983). Morerecently, because of abundant Eocene–Oligocene calc-alkaline toshoshonitic volcanic rocks in the Lut block, Pang et al. (2013) con-cluded that subduction polarity was toward the west, beneath theLut block. Other models propose involve westward subductionbeneath the Lut block (Zarrinkoub et al., 2012) and eastwardintra-oceanic subduction (Saccani et al., 2010). Ocean closure occu-red either in Middle Eocene (Camp and Griffis, 1982; Tirrul et al.,1983) or Late Cretaceous (Zarrinkoub et al., 2012; Angiboustet al., 2013). Dating of metamorphic rocks indicates Late Creta-ceous (83–87 Ma) subduction. Ophiolite emplacement occured inLate Cretaceous time. Rb–Sr dating of high pressure metamorphicrocks yields ca. 84–87 Ma ages, reflecting Late Cretaceous meta-morphism associated with subduction of the Sistan Ocean.

We have considered all the geochronological and geochemicalcharacteristics of the Birjand–Nehbandan ophiolites to present ageodynamic model (Fig. 16B and C). In this model, Sistan Oceanopening was accompanied by early eruption of N-MORB-, E-MORB-, and OIB-like lavas as well as �113–107 Ma MORB-typegabbros (Zarrinkoub et al. 2012) (Fig. 16B and C). Early Cretaceousopening is further indicated by occurrence of gabbroic rocks andAptian–Albian pelagic sediments (Babazadeh and De Wever,2004; Babazadeh, 2007). The Late Cretaceous was the time of intra-oceanic subduction near the Lut block, with eruption of SSZ-relatedlavas, associated with gabbros and depleted mantle harzburgites.This interpretation agrees with ages obtained from high-P rocksin the region (Brocker et al., 2013). Late Cretaceous pelagic sedi-ments further demonstrate that the Sistan Ocean was open.Toward the latest Cretaceous to Middle Paleocene time (ca. 70–60 Ma), the continental arc started to develop, accompanied by for-mation of calc-alkaline magmatic rocks as well as adakites and A-type granites (Pang et al., 2013). One interpretation is that the Sis-tan Ocean closed in Late Paleocene time, accompanied by post-col-lisional magmatism in response to the convective removal of thelithosphere and resultant asthenospheric upwelling duringEocene–Oligocene extensional collapse of the east Iranian orogen(Pang et al., 2013). The presence of Late Cretaceous–Early Eoceneunmetamorphosed marine clastic sediments including sandstoneand marly turbidite suggests that the Sistan Ocean was open as lateas Early Eocene time.

6.3.5. Makran ophiolitesWe have more work to do in order to understand the formation

and evolution of Makran ophiolites. It seems that ocean accretionand generation of MORB lithosphere began in Jurassic time

Afghan block Lut block

(C) Intraoceanic subduction, exhumation of high-P rocks (Late Cretaceous, ~90 Ma) to

continental margin magmatism (Late Cretaceous-Paleocene, 70-60 Ma).

E Wsedimentation of Late Cretaceous pelagic sediments

detrital sediments

exhumation of high-P rocks

Sistan oceanN-MORB, E-MORB & OIB

Afghan block Lut block

(B) Ocean accretion & MORB-OIB eruption, (Early Cretaceous, ~120 Ma).

E W

Sistan oceanN-MORB, E-MORB & OIB

MORB-type gabbros (U-Pb=113-107 Ma) sedimentation of EarlyCretaceous pelagic sediments

Continental magmatism

Sabzevar-Torbat-e-Heydarieh ophiolites

Birjand-Nehbandan ophiolites

Birjand-Nehbandan ophiolites

Turan block Lut block

(A) Intraoceanic subduction and mature arc formation (middle to Late Cretaceous, ~110 Ma).

N-NE S-SW

exhumed high-P metamorphic rocks107-105 Ma (felsic rocks)

plagiogranites100-78 Ma granitoids (97-92 Ma)

Oryan-Cheshmeshir ophiolites

Sabzevar ophiolites

Island arc magmatismintraoceanic

Fig. 16. Schematic models for the formation and evolution of the STOB and Birjand–Nehbandan oceanic basins in NE Iran. (A) Intraoceanic subduction in middle Cretaceousand then mature arc formation in Late Cretaceous were responsible for the exhumation of the high-P metamorphic rocks; formation of SSZ-related plagiogranite and othercrustal rocks and crystallization of Late Cretaceous granitoid rocks (arc rocks). (B) Oceanic lithosphere accretion and eruption of early lavas with MORB and OIB signatures.Aptian–Albian pelagic sedimentation in this basin was accompanied with plutonism and crystallization of MORB-type gabbros. (C) Intraoceanic subduction and exhumationof high-P rocks occurred during Late Cretaceous (�90 Ma), passing into continental margin magmatism during Late Cretaceous to Paleocene (70–60 Ma) (modified after Panget al., 2013).


>170 Ma. This ophiolite belt probably continues east into SW Paki-stan (Baluchistan) where there are several Jurassic–Cretaceousophiolites (e.g., Muslim Bagh, Khan et al. 2007; Bela, Zaighamand Mallick, 2000; Ras Koh, Siddiqui et al. 2012). Concerning theBajgan–Durkan zone, we see two competing hypotheses: (1) asproposed by most geologists, this zone could represent a rigidblock. Following this scenario, a Jurassic back-arc basin formedbehind the Bajgan–Durkan arc. Back-arc basin opening was accom-panied with early MORB magmatism and subsequent SSZ-typelavas during Late Jurassic to Late Paleocene time. This age isinferred from biostratigraphic ages for the interbedded sedimentswith SSZ-type lavas and/or and geochronological results from

SSZ-related plutonic rocks. (2) The Bajgan–Durkan zone could bea subducted and exhumed accretionary complex, similar to theSNSZ. In this model, inner and outer Makran ophiolites formed asa once coherent sheet as a result of intraoceanic subduction initia-tion in Late Jurassic–Early Paleocene time and the two ophiolitebelts formed by uplift and erosion associated with exhumation ofthe Bajgan–Durkan complex. Clearly more work is needed to testand refine these models.

Whatever models are developed for the tectonic evolution ofMakran ophiolites, they must help explain how these relate tothe ophiolites to the west (Zagros), north (Birjand–Nehbandan),east (Baluchistan, Pakistan), and south (Semail, Oman).


7. Conclusions

Our main understanding about the evolution of NeotethysOcean in Iran comes from its many Mesozoic and rare Cenozoicophiolites. We have identified five main belts but this should bemodified as we learn more about Iran ophiolites. There are so manyophiolites and so much subsequent deformation, sedimentation,and volcanism that we cannot yet see clearly which exposuresare related and which are not. Considering all the field, geochemi-cal and geochronological data on these ophiolites now in hand letsus conclude that: (1) Most Iranian Mesozoic ophiolites range in agefrom Jurassic to Late Cretaceous, but Late Cretaceous–Paleoceneand even Eocene ophiolitic components are also present; (2) Ira-nian Mesozoic ophiolites are subdivided into passive-type margin,SSZ-type, accretionary prism-type, and volcanic-arc type with rareMORB-type ophiolites; (3) we have much to learn about Triassic,Jurassic and Early Cretaceous ophiolites of Iran, but these mayrecord northern Gondwana rifting during Early Mesozoic timeand then sedimentation and magmatism along the passive margin;(4) Iran Mesozoic (and Cenozoic) ophiolites have SSZ, MORB- andOIB-geochemical signatures. SSZ-type geochemical signaturesdominate, particularly among Late Cretaceous ophiolites; (5) thepresence of zircon inherited cores/grains may signify the involve-ment of Cimmerian lithosphere in forming some ophiolites, a factthat also can explain the abundance of OIB magmatism in Late Cre-taceous ophiolites; and (6) the significance of Eocene ophioliteswhich occur along the Iran–Iraq border and may link to Khoy–Maku Late Cretaceous–Paleocene ophiolites is not clear. These donot have equivalents elsewhere in the Tethyan realm.

Acknowledgments

We thank Juhn G. Liou and Bor-Ming Jahn for inviting us to pre-pare this review of the origin and significance of Iranian ophiolites.We are very grateful to Akira Ishiwatari and Harald Furnes for theirconstructive reviews of the manuscript. This work is the result ofthe UT Dallas virtual postdoc program to the first author (HSM).All logistical support during field studies came from Damghan Uni-versity. This is UTD Geosciences contribution #1269.

References

Abbate, E., Bortolotti, V., Principi, G., 1980. Apennine ophiolites: a peculiar oceaniccrust. Ofioliti 1, 59–96.

Agard, P., Omrani, J., Jolivet, L., Mouthereau, F., 2005. Convergence history acrossZagros (Iran): constraints from collisional and earlier deformation. Int. J. EarthSci. 94, 401–419.

Agard, P., Monie, P., Gerber, W., Omrani, J., Molinaro, M., Meyer, B., Labrousse, L.,Vrielynck, B., Jolivet, L., Yamato, P., 2006. Transient, syn-obduction exhumationof Zagros blueschists inferred from P-T-deformation-time and kinematicconstraints: implications for Neotethyan wedge dynamics. J. Geophys. Res.111, B11401. http://dx.doi.org/10.1029/2005JB004103.

Ahmadipour, H., Sabzehi, M., Whitechurch, H., Rastad, E., Emami, M.H., 2003.Soghan complex as an evidence for paleospreading center and mantlediapirismin Sanandaj–Sirjan zone (south-east Iran). J. Sci., I. R. Iran 14, 157–172.

Alabaster, T., Pearce, J.A., Malpas, J., 1982. The volcanic stratigraphy andpetrogenesis of the Oman ophiolite complex. Contrib. Mineral. Petrol. 81,168–183.

Alaminia, Z., Karimpour, M.H., Homam, M., Fimger, F., 2013. The magmatic record inthe Arghash region (northeast Iran) and tectonic implications. Int. J. Earth Sci.http://dx.doi.org/10.1007/s00531-013-0897-1.

Alavi, M., 1991. Sedimentary and structural characteristics of the Paleo-Tethysremnants in northeastern Iran. Geol. Soc. Am. Bull. 103, 983–992.

Alavi, M., 1994. Tectonics of the Zagros orogenic belt of Iran: new data andinterpretations. Tectonophysics 229, 211–238.

Alavi, M., Bolourchi, M., 1975. Geological quadrangle map of Iran, 1:250,000 scale,sheet al (Palamakumbura et al.). Geol. Surv. Iran.

Ali, S.A., Buckman, S., Aswad, K.J., Jones, B.G., Ismail, S.A., Nutman, A.P., 2012.Recognition of Late Cretaceous Hasanbag ophiolite-arc rocks in the KurdistanRegion of the Iraqi Zagros suture zone: a missing link in the paleogeography ofthe closing Neotethys Ocean. Lithosphere 4, 395–410.

Ali, S.A., Buckman, S., Aswad, K.J., Jones, B.G., Ismail, S.A., Nutman, A.P., 2013. Thetectonic evolution of a Neo-Tethyan (Eocene–Oligocene) island-arc (Walash and

Naopurdan groups) in the Kurdistan region of the Northeast Iraqi Zagros SutureZone. The Island Arc 22, 104–125.

Angiboust, S., Agard, P., De Hoog, J.C.M., Omrani, J., Plunder, A., 2013. Insights ondeep, accretionary subduction processes from the Sistan ophiolitic ‘‘mélange’’(Eastern Iran). Lithos 156–159, 139–158.

Anma, R., Armstrong, R., Danhara, T., Orihashi, Y., Iwano, H., 2006. Zircon sensitivehigh mass-resolution ion microprobe U–Pb and fission-track ages for gabbrosand sheeted dykes of the Taitao ophiolite, Southern Chile, and their tectonicimplications. Island Arc 15, 130–142.

Arvin, M., 1982. Petrology and geochemistry of ophiolites and associated rocks fromthe Zagros suture, Neyriz, Iran, Ph.D. Thesis. London University, London.

Arvin, M., Robinson, P.T., 1994. The petrogenesis and tectonic setting of lavas fromthe Baft ophiolitic mélange, southwest of Kerman, Iran. Canad. J. Earth Sci. 31,824–834.

Arvin, M., Shokri, E., 1997. Genesis and eruptive environment of basalts from theGogher ophiolitic mélange, southwest of Kerman, Iran. Ofioliti 22, 175–182.

Arvin, M., Houseinipour, A., Babaei, A.A., Babaie, H.A., 2001. Geochemistry andtectonic significance of basalts in the Dare–Anar complex: evidence from theKahnuj ophiolitic complex, southeastern Iran. J. Sci. I. R. Iran 12 (2), 157–170.

Arvin, M., Babaei, A., Ghadami, G., Dargahi, S., Ardekani, A.S., 2005. The origin of theKahnuj ophiolitic complex, SE of Iran: constraints from whole rock and mineralchemistry of the Bande–Zeyarat gabbroic complex. Ofioliti 30 (1), 1–14.

Azizi, H., Moinevaziri, H., Mohajjel, M., Yagobpoor, A., 2005. PTt path in metamorphicrocks of the Khoy region (northwest Iran) and their tectonic significance forCretaceous-Tertiary continental collision. J. Asian Earth Sci. 27, 1–9.

Azizi, H., Chung, S.L., Tanaka, T., Asahara, Y., 2011. Isotopic dating of the Khoymetamorphic complex (KMC), northwestern Iran: a significant revision of theformation age and magma source. Precambr. Res. 185, 87–94.

Babaei, H.A., Ghazi, A.M., Babaei, A., Latour, T.E., Hassanipak, A.A., 2001.Geochemistry of arc volcanic rocks of the Zagros Crush Zone, Neyriz, Iran. J.Asian Earth Sci. 19, 61–76.

Babaei, H.A., Babaei, A., Arvin, M., 2005. Tectonic evolution of the Neyriz ophiolite,Iran: an accretionary model. Ofioliti 30, 65–74.

Babaei, H.A., Babaei, A., Ghazi, A.M., Arvin, M., 2006. Geochemical, 40Ar/39Ar age, andisotopic data for crustal rocks of the Neyriz ophiolite, Iran. Canad. J. Earth Sci.43, 57–70.

Babazadeh, S.A., De Wever, P., 2004. Radiolarian Cretaceous age of Soulabestradiolarites in ophiolite suite of eastern Iran. Bull. Soci. Géol. Fr. 175 (2),121–129.

Bagci, U., Parlak, O., Hock, V., 2008. Geochemistry and tectonic environment ofdiverse magma generations forming the crustal units of the Kizildag (Hatay)ophiolite, southern Turkey. Turk. J. Earth Sci. 17, 43–71.

Baroz, F., Macaudiere, J., 1984. La serie volcanosedimentaire du chainonophiolitique de Sabzevar (Iran). Ofioliti 9, 3–26.

Berberian, M., King, G.C.P., 1981. Towards a paleogeography and tectonic evolutionof Iran. Can. J. Earth Sci. 18, 210–265.

Braud, J., 1987. La suture du Zagros au niveau de Kermanshah (Kurdistan Iranien):Reconstitution paleogeographique, evolution geodynamique, magmatique etstructurale, Ph.D. theses. Universite Paris-Sud, 489p.

Brocker, M., Fotoohi Rad, G.R., Theunissen, S., 2010. New time constraints for HPmetamorphism and exhumation of mélange rocks from the Sistan suture zone,Eastern Iran. Tectonic Crossroads: Evolving Orogens of Eurasia-Africa-Arabia.Session No. 13. Ophiolites, blueschists, and suture zones.

Brocker, M., Fotoohi Rad, G.R., Burgess, R., Theunissen, S., Paderin, I., Rodionov, N.,Salimi, Z., 2013. New age constraints for the geodynamic evolution of the SistanSuture Zone, eastern Iran. Lithos 170–171, 17–34.

Camp, V.E., Griffis, R.J., 1982. Character, genesis and tectonic setting of igneousrocks in the Sistan suture zone, eastern Iran. Lithos 15, 221–239.

Çelik, Ö.F., Delaloye, M., 2003. Origin of metamorphic soles and their post-kinematicmafic dyke swarms in the Antalya and Lycian ophiolites, SW Turkey. Geol. J. 38,235–256.

Çelik, Ö.F., Marzoli, A., Marschik, R., Chiaradia, M., Neubauer, F., Öz, I., 2011. Early-Middle Jurassic intra-oceanic subduction in the _Izmir–Ankara–Erzincan Ocean,Northern Turkey. Tectonophysics 509, 120–134.

Delaloye, M., Desmons, J., 1980. Ophiolites and mélange terranes in Iran: ageochronological study and its paleotectonic implications. Tectonophysics 68,83–111.

Delavari, M., Amini, S., Saccani, E., Beccaluva, L., 2009. Geochemistry andPetrogenesis of Mantle Peridotites from the Nehbandan Ophiolitic Complex,Eastern Iran. J. Appl. Sci. 9, 2671–2687.

Dercourt, J., Zonenshain, L.P., et al., 1986. Geological evolution of the Tethys beltfrom the Atlantic to the Pamirs since the Lias. Tectonophysics 123, 241–315.

Desmons, J., Beccaluva, L., 1983. Mid-ocean ridge and island arc affinities inophiolites from Iran: palaeographic implications. Chem. Geol. 39, 39–63.

Dilek, Y., Flower, M.F.J., 2003. Arc-trench rollback and forearc accretion: 2. A modeltemplate for ophiolites in Albania, Cyprus, and Oman. Ophio. Earth History 218,43–68.

Dilek, Y., Furnes, H., 2009. Structure and geochemistry of Tethyan ophiolites andtheir petrogenesis in subduction rollback systems. Lithos 113, 1–20.

Dilek, Y., Furnes, H., 2011. Ophiolite genesis and global tectonics: geochemical andtectonic fingerprinting of ancient oceanic lithosphere. Geol. Soc. Am. Bull. 123,387–411.

Dilek, Y., Furnes, H., 2014. Ophiolites and their origins. Elements 10, 93–100.Dilek, Y., Thy, P., 2009. Island arc tholeiite to boninitic melt evolution of the

Cretaceous Kizildag (Turkey) ophiolite: model for multi-stage early arc–forearcmagmatism in Tethyan subduction factories. Lithos 113, 68–87.

http://refhub.elsevier.com/S1367-9120(15)00011-5/h0005





http://dx.doi.org/10.1029/2005JB004103







http://dx.doi.org/10.1007/s00531-013-0897-1




























































































Ernewein, M., Pflumino, C., Whitechurch, H., 1988. The death of an accretion zone asevidenced by the magmatic history of the Sumail ophiolite (Oman).Tectonophysics 151, 247–274.

Fotoohi Rad, G.R., Droop, G.T.R., Amini, S., Moazzen, M., 2005. Eclogites andblueschists of the Sistan Suture Zone, eastern Iran: a comparison of P-T historiesfrom a subduction melange. Lithos 84 (1–2), 1–24.

Fotoohi Rad, G.R., Droop, G.T.R., Burgess, R., 2009. Early Cretaceous exhumation ofhigh-pressure metamorphic rocks of the Sistan Suture Zone, eastern Iran. Geol.J. 44, 104–116.

Furnes, H., De Wit, M., Dilek, Y., 2014. Four billion years of ophiolites reveal seculartrends in oceanic crust formation. Geosci. Front. 5, 571–603.

Galoyan, G., Rolland, Y., Sosson, M., Corsini, M., Billo, S., Verati, C., Melkonyan, R.,2009. Geology, geochemistry and 40Ar/39Ar dating of Sevan ophiolites (LesserCaucasus, Armenia): evidence for Jurassic Back-arc opening and hot spot eventbetween the South Armenian Block and Eurasia. J. Asian Earth Sci. 34, 135–153.

Ghasemi, H., Juteau, T., Bellon, H., Sabzehi, M., Whitechurch, H., Ricou, L.E., 2002.The mafic-ultramafic complex of Sikhoran (central Iran): a polygenetic ophiolitecomplex. C. R. Geosci. 334, 431–438.

Ghazi, A.M., Hassanipak, A.A., 2000. Petrology and geochemistry of the Shahr–Babakophiolite, Central Iran. Geol. Surv. Am. Spec. Pap. 349, 485–497.

Ghazi, A.M., Pessagno, E.A., Hassanipak, A.A., Kariminia, S.M., Duncan, R.A., Babaie,H.A., 2003. Biostratigraphic zonation and 40Ar–39Ar ages for the Neotethyan Khoyophiolite of NW Iran. Palaeogeogr. Palaeoclimatol. Palaeoecol. 193, 311–323.

Ghazi, A.M., Hassanipak, A.A., Mahoney, J.J., Duncan, R.A., 2004. Geochemicalcharacteristics, 40Ar–39Ar ages and original tectonic setting of the Band-e-Zeyarat/Dar Anar ophiolite, Makran accretionary prism, S.E, Iran.Tectonophysics 393, 175–196.

Ghoraishi, M., Arshadi, S. 1978. Geological map of the Khoy Quadrangle, Scale 1/250000. Geological Survey of Iran.

Glennie, K.W., 2000. Cretaceous tectonic evolution of Arabia’s eastern plate margin:a tale of two oceans. In: Alsharan, A.S., Scott, R.W. (Eds.), Middle East Models ofJurassic/Cretaceous Carbonate Systems. Society of Economic Paleontologistsand Mineralogists (SEPM) Special Publication no. 69, pp. 9–20.

Glennie, K.W., Hughes Clarke, M.W., Boeuf, M.G.A., Pilaar, W.F.H., Reinhardt, B.M.,1990. Inter-relationship of Makran-Oman Mountains: belts of convergence. In:Robertson, A.H.F., Searle, M.P., Ries, A.C., (Eds.), The geology and tectonics of theOman region, vol. 49. Geological Society of London Special Publication, pp. 773–786.

Hacker, B.R., Mosenfelder, J.L., Gnos, E., 1996. Rapid emplacement of the Omanophiolite: thermal and geochronologic constraints. Tectonics 15, 1230–1247.

Hassanipak, A.A., Ghazi, M., 2000. Petrology, geochemistry and tectonic setting ofthe Khoy ophiolite, northwest Iran: implications for Tethyan tectonics. J. AsianEarth Sci. 18, 109–121.

Hassanipak, A.A., Ghazi, A.M., Wampler, J.M., 1996. REE characteristics and K/Arages of the Band Ziarat ophiolite complex, southeastern Iran. Can. J. Earth Sci.33, 1534–1542.

Hassanzadeh, J., Stockli, D.F., Horton, B.K., Axen, G.J., Stockli, L.D., Grove, M., Schmitt,A.K., Walker, J.D., 2008. U–Pb zircon geochronology of Late Neoproterozoic-Early Cambrian granitoids in Iran: implications for paleogeography,magmatism, and exhumation history of Iranian basement. Tectonophysics451, 71–96.

Hassig, M., Rolland, Y., Sosson, M., Galoyan, G., Muller, C., Avagyan, A., Sahakyan, L.,2013. New structural and petrological data on the Amasia ophiolites (NWSevan-Akera suture zone, Lesser Caucasus): insights for a large-scale obductionin Armenia and NE Turkey. Tectonophysics 588, 135–153.

Hirano, N., Ogawa, Y., Saito, K., Yoshida, T., Sato, H., Taniguchi, H., 2003. Multi-stageevolution of the Tertiary Mineoka ophiolite, Japan: new geochemical and ageconstraints. Ophio. Earth History 218, 279–298.

Hunziker, D., Burg, J.-P., Bouilhol, P., Omrani, J., 2011. Percolation and impregnationof a plagioclase-rich melt into the mantlecrust transition zone of the Makranophiolites, SE Iran, Abstract Volume 9th Swiss Geoscience Meeting Zurich,11th–13th November.

Ishikawa, A., Kaneko, Y., Kadarusman, A., Ota, T., 2007. Multiple generations offorearc mafic–ultramafic rocks in the Timor–Tanimbar ophiolite, easternIndonesia. Gondwana Res. 11, 200–217.

Ishiwatari, A., 1985. Granulite-Facies Metacumulates of the Yakuno Ophiolite, Japan– Evidence for Unusually Thick Oceanic-Crust. J. Petrol. 26, 1–30.

Jahn, B.M., 1986. Midocean ridge or marginal basin origin of the east Taiwanophiolite – chemical and isotopic evidence. Contrib. Miner. Petrol. 92, 194–206.

Jamshidi Badr, M., Collins, A.S., Masoudi, F., Cox, G., Mohajjel, M., 2011. The U–PbAge, geochemistry and tectonic significance of Granitoids in the Soursatcomplex, Northwest Iran. Turk. J. Earth Sci. 21. http://dx.doi.org/10.3906/yer-1001-37.

Kananian, A., Juteau, T., Bellon, H., Darvishzadeh, A., Sabzehi, M., Whitechurch, H.,Ricou, L.-E., 2001. The ophiolite massif of Kahnuj (western Makran, southernIran): new geological and geochronological data. Comp. Rendus de l’Acad. Sci.332, 543–552.

Kaneko, Y., Maruyama, S., Kadarusman, A., Ota, T., Ishikawa, M., Tsujimori, T.,Ishikawa, A., Okamotoa, K., 2007. On-going orogeny in the outer-arc of the Timor-Tanimbar region, eastern Indonesia. Gondwana Research 11 (1–2), 218–233.

Khalatbari-Jafari, M., Juteau, T., Bellon, H., Emami, H., 2003. Discovery of twoophiolite complexes of different ages in the Khoy area (NW Iran). CR Geosci.Acad. Sci., 917–929

Khalatbari-Jafari, M., Juteau, T., Bellon, H., Whitechurch, H., Cotten, J., Emami, H.,2004. Newgeological, geochronological and geochemical investigations on theKhoy ophiolites and relatedformations, NW Iran. J. Asian Earth Sci. 23, 507–535.

Khalatbari-Jafari, M., Juteau, T., Cotten, J., 2006. Petrological and geochemical studyof the Late Cretaceous ophiolite of Khoy (NW Iran) and related geologicalformations. J. Asian Earth Sci. 27, 465–502.

Khan, M., Kerr, A.C., Mahmood, K., 2007. Formation and tectonic evolution of theCretaceous–Jurassic Muslim Bagh ophiolitic complex, Pakistan: implications forthe composite tectonic setting of ophiolites. J. Afr. Earth Sc. 31, 112–127.

Knipper, A., Ricou, L.E., Dercourt, J., 1986. Ophiolites as indicators of the geodynamicevolution of the Tethyan ocean. Tectonophysics 123, 213–240.

Lanphere, M.A., Pamic, T., 1983. 40Ar/39Ar ages and tectonic setting of ophiolitesfrom Neyriz area, southeast Zagros range, Iran. Tectonophysics 96, 245–256.

Lensch, G., Mihm, A., Alavi-Tehrani, N., 1980. The post-ophiolitic volcanics north ofSabzevar (Iran): geology, petrography and major éléments geochemistry. NeuesJahrb. Geol. Palaontol. Monatsh. 11, 686–702.

Lindenberg, H.G., Gorler, K., Ibbeken, H., 1983. Stratigraphy, structure and orogenicevolution of the Sabzevar zone in the area of Oryan (Khorasan, NE Iran). Geol.Surv. Iran, Report 51, 119–143.

McCall, G.J.H., 1983. Melanges of the Makran, southern Iran. In: McCall, G.J.H. (Ed.),Ophiolitic and Related Melanges, vol. 66. Hutchinson and Ross, Stroudsburg, PA.Benchmark Pap. Geol., pp. 292–299.

McCall, G.J.H., 1985. Explanatory text of the Minab Quadrangle, Map; 1:250,000;No. J13. Geological Survey of Iran, Tehran, 530 p.

McCall, G.J.H., 1997. The geotectonic history of the Makran and adjacent areas ofsouthern Iran. J. Asian Earth Sci. 15 (Robinson et al.), 517–531.

McCall, G.J.H., 2002. A summary of the geology of the Iranian Makran. In: Clift, P.D.,Kroon, F.D., Gaedecke, C., Craig, J., (Eds.), The Tectonic and Climatic Evolution ofthe Arabian Sea Region. Special Publication of the Geological Society of LondonNo. 195, pp. 147–204.

McCall, G.J.H., 2003. A critique of the analogy between Archaean and Phanerozoictectonics based on regional mapping of the Mesozoic–Cenozoic plateconvergent zone in the Makran, Iran. Precamb. Res. 127, 5–17.

McCall, G.J.H., Kidd, R.G.W., 1982. The Makran, Southeastern Iran: the Anatomy of aConvergent Plate Margin Active from Cretaceous to Present, vol. 10. GeologicalSociety, London, Special Publications, pp. 387–397.

Mehdipour Ghazi, J., Moazzen, M., Rahgoshay, M., Shafaii Moghadam, H., 2012.Geochemical characteristics of basaltic rocks from the Nain ophiolite (CentralIran); constraints on mantle wedge source evolution in an oceanic back arcbasin and a geodynamical model. Tectonophysics 574–575, 92–104.

Monsef, I., Rahgoshay, M., Mohajjel, M., Shafaii Moghadam, H., 2010. Peridotitesfrom the Khoy ophiolite complex, NW Iran: evidences of mantle dynamics in aSupra-Subduction-zone context. J. Asian Earth Sci. 38, 105–120.

Moores, E.M., Kellogg, L.H., Dilek, Y., 2000, Tethyan ophiolites, mantle convection,and tectonic ‘‘historical contingency’’; a resolution of the ‘‘ophioliteconundrum’’. In: Dilek, Y., Moores, E.M., Elthon, D., Nicolas, A. (Eds.),Ophiolites and Oceanic Crust: New Insights from Field Studies and the OceanDrilling Program: Geological Society of America Special Paper 349, pp. 3–12.

Mukasa, S.B., Ludden, J.N., 1987. Uranium-lead isotopic ages of plagiogranites from theTroodos ophiolite, Cyprus, and their tectonic significance. Geology 15, 825–828.

Muntener, O., Manatschal, G., Desmurs, L., Pettke, T., 2010. Plagioclase peridotites inocean-continent transitions: refertilized mantle domains generated by meltstagnation in the shallow mantle lithosphere. J. Petrol. 51, 255–294.

Omrani, H., Moazzen, M., Oberhansli, R., Altenberger, U., Lange, M., 2013. TheSabzevar blueschists of the North-Central Iranian micro-continent as remnantsof the Neotethys-related oceanic crust subduction. Int. J. Earth Sci. http://dx.doi.org/10.1007/s00531-013-0881-9.

Osozawa, S., Shinjo, R., Lo, C.H., Jahn, B.M., Hoang, N., Sasaki, M., Ishikawa, K., Kano,H., Hoshi, H., Xenophontos, C., Wakabayashi, J., 2012. Geochemistry andgeochronology of the Troodos ophiolite: an SSZ ophiolite generated bysubduction initiation and an extended episode of ridge subduction?Lithosphere 4, 497–510.

Pamic, J., Adib, D., 1982. High-grade amphibolites and granulites at the base of theNeyriz peridotities in southeastern Iran. N. Jb. Miner. Abh. 143, 113–121.

Pang, K.P., Chung, S.L., Zarrinkoub, M.H., Khatib, M.M., Mohammadi, S.S., Chiu, H.Y.,Chu, C.H., Lee, H.Y., Lo, C.H., 2013. Eocene–Oligocene post-collisionalmagmatism in the Lut–Sistan region, eastern Iran: magma genesis andtectonic implications. Lithos 180–181, 234–251.

Parlak, O., Yilmaz, H., Boztug, D., 2006. Origin and tectonic significance of themetamorphic sole and isolated dykes of the Divrigi Ophiolite (Sivas, Turkey):evidence for slab break-off prior to ophiolite emplacement. Turk. J. Earth Sci. 15,25–45.

Pearce, J.A., 2008. Geochemical fingerprinting of oceanic basalts with applications toophiolite classification and the search for Archean oceanic crust. Lithos 100, 14–48.

Pearce, J.A., Robinson, P.T., 2010. The Troodos ophiolite complex probably formed ina subduction initiation, slab edge setting. Gondwana Res. 18, 60–81.

Poor Mohsen, M., Rahgoshay, M., Azadi, I., Shafaii Moghadam, H., 2010.Geochemistry and petrogenesis of basaltic-andesitic rocks in Siah-Cheshmehophiolite, NW Khoy. J. Geo. Scien. Quart. 77, 131–136 (in Persian with Englishabstract).

Rezai, M., Moazzen, M., Hajialioghli, R., Morishita, T., 2010. Olivine, Pyroxene andspinel geochemistry in Chalderan (Maku) Ophiolites: implications forgeodynamic setting. In: 15th Symposium of Geological Society of Iran, p. 12(in Perian).

Ricou, L.E., Braud, J., Brunn, J.H., 1977. Le Zagros. Société Géologique de France.Mémoire Hors Série 8, 33–52.

Robertson, A.H.F., 2002. Overview of the genesis and emplacement of Mesozoicophiolites in the Eastern Mediterranean Tethyan region. Tectonophysics 65,1–67.





























































http://dx.doi.org/10.3906/yer-1001-37

http://dx.doi.org/10.3906/yer-1001-37















































http://dx.doi.org/10.1007/s00531-013-0881-9

http://dx.doi.org/10.1007/s00531-013-0881-9






























Rolland, Y., Billo, S., Corsini, M., Sosson, M., Galoyan, G., 2009a. Blueschists of theAmasia-Stepanavan Suture Zone (Armenia): linking Tethys subduction historyfrom E Turkey to W-Iran. Int. J. Earth Sci. (Geologische Rundschau) 98, 533–550.

Rolland, Y., Galoyan, Gh., Bosch, D., Sosson, M., Corsini, M., Fornari, M., Vérati, C.,2009b. Jurassic back-arc and hot-spot related series in the Armenian ophiolites– implications for the obduction process. Lithos 112, 163–187.

Rolland, Y., Galoyan, G., Sosson, M., Melkonian, R., Avagyan, A., 2010. The Armenianophiolites: insights for Jurassic back-arc formation, Lower Cretaceous hot-spotmagmatism, and Upper Cretaceous obduction over the South Armenian Block.In: Sosson, M., Kaymakci, N., Stephanson, R., Bergarat, F., Storatchenoko, V.(Eds.), Sedimentary basin tectonics from the Black Sea and Caucasus to theArabian Platform, vol. 340. Geological Society of London, Special Publication, pp.353–382.

Rossetti, F., Nasrabady, M., Vignaroli, G., Theye, T., Gerdes, A., Razavi, S.M.H., MoinVaziri, H., 2010. Early Cretaceous migmatitic mafic granulites from the Sabzevarrange (NE Iran): implications for the closure of the Mesozoic peri-Tethyanoceans in central Iran. Terra Nova 22, 26–34.

Saccani, E., Delavari, M., Beccaluva, L., Amini, S., 2010. Petrological andgeochemicalconstraints on the origin of the Nehbandan ophiolitic complex(eastern Iran): implication for the evolution of the Sistan Ocean. Lithos 117,209–228.

Saccani, E., Allahyari, K., Beccaluva, L., Bianchini, G., 2013. Geochemistry andpetrology of the Kermanshah ophiolites (Iran): implication for the interactionbetween passive rifting, oceanic accretion, and OIB-type components in thesouthern Neo-Tethys Ocean. Gondwana Res. 24, 392–411.

Saccani, E., Allahyari, K., Rahimzadeh, B., 2014. Petrology and geochemistry of maficmagmatic rocks from the Sarve-Abad ophiolites (Kurdistan region, Iran):evidence for interaction between MORB-type asthenosphere and OIB-typecomponents in the southern Neo-Tethys Ocean. Tectonophysics 621, 132–147.

Sengor, A.M.C. 1990. A new model for the Late Palaeozoic-Mesozoic tectonicevolution of Iran and implications for Oman. In: Robertson, A.H.F., Searle, M.P.,Ries, A.C. (Eds.), The Geology and Tectonics of the Oman Region. GeologicalSociety of London, Special Publication no. 49, pp. 797–831.

Shafaii Moghadam, S., Corfu, F., Chiaradia, M., Stern, R.J., Ghorbani, G., 2014.Sabzevar Ophiolite, NE Iran: Progress from embryonic oceanic lithosphere intomagmatic arc constrained by new isotopic and geochemical data. Lithos 210–211, 224–241.

Shafaii Moghadam, H., Stern, R.J., 2011. Geodynamic evolution of upper CretaceousZagros ophiolites: formation of oceanic lithosphere above a nascent subductionzone. Geol. Mag. 148, 762–801.

Shafaii Moghadam, H., Stern, R.J., 2014. Ophiolites of Iran: keys to understandingthe tectonic evolution of SW Asia: (I) Paleozoic ophiolites. J. Asian Earth Sci. 91,19–38.

Shafaii Moghadam, H., Whitechurch, H., Rahgoshay, M., Monsef, I., 2009.Significance of Nain-Baft ophiolitic belt (Iran): short-lived, transtensionalCretaceous back-arc oceanic basins over the Tethyan subduction zone. Comp.Rendus Geosci. 341, 1016–1028.

Shafaii Moghadam, H., Stern, R.J., Rahgoshay, M., 2010. The Dehshir ophiolite(central Iran): Geochemical constraints on the origin and evolution of the InnerZagros ophiolite belt. Geol. Soc. Am. Bull. 122, 1516–1547.

Shafaii Moghadam, H., Mosaddegh, H., Santosh, M., 2012. Geochemistry andpetrogenesis of the Late Cretaceous Haji-Abad ophiolite (Outer ZagrosOphiolite Belt, Iran): implications for geodynamics of the Bitlis-Zagros suturezone. Geol. J. http://dx.doi.org/10.1002/gj.2458.

Shafaii Moghadam, H., Stern, R.J., Chiaradia, M., Rahgoshay, M., 2013a.Geochemistry and tectonic evolution of the Late Cretaceous Gogher-Baftophiolite, central Iran. Lithos 16–169, 33–47.

Shafaii Moghadam, H., Zaki Khedr, M., Arai, S., Stern, R.J., Ghorbani, G., Tamura, A.,Ottley, C., 2013b. Arc-related harzburgite–dunite–chromitite complexes in themantle section of the Sabzevar ophiolite, Iran: a model for formation ofpodiform chromitites. Gond. Res., http://dx.doi.org/10.1016/j.gr.2013.09.007.

Shafaii Moghadam, H., Corfu, F., Stern, R.J., 2013c. U–Pb Zircon ages of LateCretaceous Nain-Dehshir ophiolite, Central Iran. J. Geol. Soc. London 170, 175–184.

Shahabpour, J., 2010. Tectonic implications of the geochemical data from theMakran igneous rocks in Iran. Island Arc 19, 676–689.

Shaker Ardakani, A.R., Arvin, M., Oberhanli, R., Mocek, B., Moeinzadeh, S.H., 2009.Morphology and Petrogenesis of Pillow Lavas from the Ganj Ophiolitic Complex,Southeastern Kerman, Iran. J. Sci., I. R. Iran 20, 139–151.

Shervais, J.W., 1982. Ti–V plots and the petrogenesis of modern and ophiolitic lavas.Earth Planet. Sci. Lett. 59, 101–118.

Shervais, J.W., 2001. Birth, death, and resurrection: the life cycle of suprasubductionzone ophiolites. Geochem. Geophys. Geosyst. 2. http://dx.doi.org/10.1029/2000GC000080.

Shojaat, B., Hassanipak, A.A., Mobasher, K., Ghazi, A.M., 2003. Petrology,geochemistry and tectonics of the Sabzevar ophiolite, north central Iran. J.Asian Earth Sci. 21, 1053–1067.

Siddiqui, H., Jan, M.Q., Khan, M.A., 2012. Petrogenesis of Late Cretaceous lava flowsfrom a Ceno-Tethyan island arc: the Raskoh arc, Balochistan, Pakistan. J. AsianEarth Sci. 59, 24–38.

Stampfli, G.M., Borel, G.D., 2002. A plate tectonic model for the Paleozoic andMesozoic constrained by dynamic plate boundaries and restored syntheticoceanic isochrons. Earth Planet. Sci. Lett. 196, 17–33.

Thy, P., Xenophontos, C., 1991. Crystallization orders and phase chemistry of glassylavas from the pillow sequences, Troodos ophiolite, Cyprus. J. Petrol. 32,403–428.

Tirrul, R., Bell, I.R., Griffis, R.J., Camp, V.E., 1983. The Sistan Suture Zone of easternIran. Geol. Soc. Am. Bull. 94, 134–150.

Veloso, E.A.E., Anma, R., Yamazaki, T., 2005. Tectonic rotations during the ChileRidge collision and obduction of the Taitao ophiolite (southern Chile). Island Arc14, 599–615.

Walker, J.D., Geissman, J.W., Bowring, S.A., Babcock, L.E., compilers, 2012. Geologictime scale v. 4.0. Geol. Soc. Am., http://dx.doi.org/10.1130/2012.CTS004R3C.

Whattam, S.A., Stern, R.J., 2011. The ‘subduction initiation rule’: a key for linkingophiolites, intra-oceanic forearcs, and subduction initiation. Contrib. Miner.Petrol. 162, 1031–1045.

Whitechurch, H., Omrani, J., Agard, P., Humbert, F., Montigny, R., Jolivet, L., 2013.Evidence for Paleocene–Eocene evolution of the foot of the Eurasian margin(Kermanshah ophiolite, SW Iran) from back-arc to arc: implications for regionalgeodynamics and obduction. Lithos 182–183, 11–32.

Yumul, G.P., 2007. Westward younging disposition of Philippine ophiolites and itsimplication for arc evolution. Island Arc 16, 306–317.

Zaigham, N.A., Mallick, K.A., 2000. Bela ophiolite zone of southern Pakistan:tectonic setting and associated mineral deposits. Geol. Soc. Am. Bull. 112,478–489.

Zarrinkoub, M.H., Pang, K.N., Chung, S.L., Khatib, M.M., Mohammadi, S.S., Chiu, H.Y.,Lee, H.Y., 2012. Zircon U–Pb age and geochemical constraints on the origin ofthe Birjand ophiolite, Sistan suture zone, eastern Iran. Lithos 154, 392–405.








































http://dx.doi.org/10.1002/gj.2458




http://dx.doi.org/10.1016/j.gr.2013.09.007











http://dx.doi.org/10.1029/2000GC000080

http://dx.doi.org/10.1029/2000GC000080


















http://dx.doi.org/10.1130/2012.CTS004R3C
















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