The East Anatolia–Lesser Caucasus ophiolite: An exceptional case of large-scale obduction, synthesis of data and numerical modelling

Rolland, Yann; Hässig, Marc; Bosch, Delphine; Bruguier, Olivier; Melis, Raphaël; Galoyan, Ghazar; Topuz, Gültekın; Sahakyan, Lilit; Avagyan, Ara; Sosson, Marc

doi:10.1016/j.gsf.2018.12.009

Cited by 46 publications

(30 citation statements)

References 140 publications

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“…The new evidence of Early Cretaceous plume-ridge interaction in the Band-e-Zeyarat ophiolite is, therefore, highly significant as they represent, up to now, the earliest witness of mantle plume activity in the Makran sector of the Neo-Tethys. This conclusion fits well and improves the extant literature data from Makran [22,53,102] and neighboring collisional belts [90,95,108,109], which point out a plume activity starting in the Early Cretaceous and continuing in the Late Cretaceous in the Neo-Tethys realm. This data agrees well with the evidence for two major pulses of mantle plume activities at a worldwide scale during the Early and Late Cretaceous (i.e., from 122 to 70 Ma, see Reference [27]); in fact, examples of oceanic plateau and continental flood basalts associated with Cretaceous mantle plume are well-known in the Indian Ocean (e.g., Kerguelen Plateau [28]), in the Pacific Ocean (e.g., Ontong Java Plateau [29,30]; Hikurangi Plateau [31]), and in the Caribbean region (Caribbean Plateau [29]).…”

Section: Tectono-magmatic Setting Of Formation Of the Band-e-zeyarat supporting

confidence: 90%

“…In any case, these data point out that during the Late Cretaceous, a mantle plume activity strongly influenced the magmatic history of the Northern Makran Ocean. Accordingly, mantle plume activity has been documented in the Early Cretaceous at a regional scale from the Caucasus to Tibet [108,109].…”

Section: Tectono-magmatic Setting Of Formation Of the Band-e-zeyarat mentioning

confidence: 99%

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Early Cretaceous Plume–Ridge Interaction Recorded in the Band-e-Zeyarat Ophiolite (North Makran, Iran): New Constraints from Petrological, Mineral Chemistry, and Geochronological Data

et al. 2020

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The North Makran domain (southeast Iran) is part of the Makran accretionary wedge and consists of an imbricate stack of continental and Neo-Tethyan oceanic tectonic units. Among these, the Band-e-Zeyarat ophiolite consists of (from bottom to top): ultramafic cumulates, layered gabbros, isotropic gabbros, a sheeted dyke complex, and a volcanic sequence. Sheeted dykes and volcanic rocks are mainly represented by basalts and minor andesites and rhyolites showing either normal-type (N) or enriched-type (E) mid-ocean ridge basalt affinities (MORB). These conclusions are also supported by mineral chemistry data. In addition, E-MORBs can be subdivided in distinct subtypes based on slightly different but significant light rare earth elements, Th, Nb, TiO2, and Ta contents. These chemical differences point out for different partial melting conditions of their mantle sources, in terms of source composition, partial melting degrees, and melting depths. U-Pb geochronological data on zircons from intrusive rocks gave ages ranging from 122 to 129 Ma. We suggest that the Band-e-Zeyarat ophiolite represents an Early Cretaceous chemical composite oceanic crust formed in a mid-ocean ridge setting by partial melting of a depleted suboceanic mantle variably metasomatized by plume-type components. This ophiolite records, therefore, an Early Cretaceous plume–ridge interaction in the Makran Neo-Tethys.

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Section: Tectono-magmatic Setting Of Formation Of the Band-e-zeyarat supporting

confidence: 90%

Section: Tectono-magmatic Setting Of Formation Of the Band-e-zeyarat mentioning

confidence: 99%

Early Cretaceous Plume–Ridge Interaction Recorded in the Band-e-Zeyarat Ophiolite (North Makran, Iran): New Constraints from Petrological, Mineral Chemistry, and Geochronological Data

et al. 2020

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“…Abundant Early Cretaceous (117 Ma) alkaline pillow lavas with OIB nature covers the older rocks (Rolland et al, 2009). These rocks are covered in turn by Late Cretaceous calc‐alkaline lavas with SSZ chemical features (Rolland et al, 2010, 2019).…”

Section: Discussionmentioning

confidence: 99%

“…They show a minimum age of 95 Ma for initiation of intra‐oceanic subduction. The metamorphic ages are 94–91 Ma and 73–71 Ma (Rolland et al, 2019; Rolland, Billo, Corsini, Sosson, & Galoyan, 2009). These ages are similar to the metamorphic ages of the Refahiye metabasites (94.1 and 60.7 Ma) and phyllites from the volcanic arc in Erzincan (ca.…”

Section: Discussionmentioning

confidence: 99%

Early Cretaceous (Albian) intra‐oceanic subduction in northern branch of Neotethys in NW Iran: Zircon U–Pb geochronology and geochemistry of ophiolitic metagabbros from the Chaldoran area

2020

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The Chaldoran ophiolite in NW Iran and at the Turkish border is a part of the larger Khoy ophiolite. Serpentinized peridotites, pillow basalt, cumulate and isotropic gabbro, pelagic limestone, and radiolarite along with volcano‐sedimentary units are the main rock types in the area. These rocks are mixed together in some places as tectonic and “coloured” mélanges. The gabbro consituent of this ophiolite is either fresh or is metamorphosed up to upper greenschist facies. These meta‐basic rocks contain relatively large crystals of plagioclase and clinopyroxene, partially changed to amphibole. Metamorphic epidote is formed in some samples. Whole‐rock chemistry of these rocks shows a basaltic magmatic composition. Low SiO2 contents along with relatively high MgO and FeOtotal contents testify for a mantle source for the parental magma of the studied samples, intermediate between tholeiitic and calc‐alkaline series. LREE and HFSE are slightly depleted and LILE show enrichment in the studied samples and Ta, Nb, Ti show negative anomalies with respect to MORBs. All chemical features are compatible with a supra‐subduction zone setting for the rocks. The studied rocks are similar to primitive arc and less evolved rocks, geochemically. Also the samples show both MORB‐like magmas, formed at the initial stage of a subduction and IAT chemical features. U–Pb dating of zircons on the gabbro sample gave 107.5 ± 1.3 Ma (Albian) crystallization age. The metabasites from the Chaldoran ophiolite are similar to intra‐oceanic ophiolite‐related igneous rocks from the Zagros suture zone in Iran and NE Iraq and equivalent rocks from the Neotethyan sutures in east Turkey and Armenia and basic rocks from the Late Cretaceous ophiolites of the outer Zagros and Taurus, which are related to the subduction initiation (SI) stage.

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“…This ~24 million km 2 region ( Figure 1) includes active rifts and collision belts, a complex pattern of continental and oceanic crusts of different ages, intense seismic activity, as well as several high-amplitude gravity anomalies and seismic velocity anomalies observed at great depths. In this region, zones of the final phases of subduction and the initial stages of rifting (spreading) are comparatively closely located (e.g., [4] [5] [6] [7] [8]). The region is located in the junction zone between East Gondwana and Eurasia, the geological-geophysical instability of which is determined by the intensity of geodynamics-both collisional and rift spreading.…”

Section: Introductionmentioning

confidence: 99%

Combined Multifactor Evidence of a Giant Lower-Mantle Ring Structure below the Eastern Mediterranean

Eppelbaum¹,

Ben‐Avraham²,

Katz³

et al. 2020

POS

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In the Arabian-Northern African region, interaction of the Nubian, Arabian and Eurasian plates and many small tectonic units is conspicuous. In order to better understand this interaction, we use satellite derived gravity data (retracked to the Earth's surface) recognized now as a powerful tool for tectono-geodynamic zonation. We applied the polynomial approximation to the gravity data which indicated the presence of a large, deep ring structure in the eastern Mediterranean centered below the Island of Cyprus. Quantitative analysis of residual gravity anomaly provides an estimate of the deep anomalous body's upper edge at a depth of about 1700 km. Computations of the residual gravity anomalies for the lower mantle also indicate presence of anomalous sources. The GPS vector pattern coinciding with the gravity trend implies counter clockwise rotation of this structure. Independent analyses of the geoid isolines map and seismic tomography data support the existence of a deep anomaly. Paleomagnetic data analysis from the surrounding regions confirms a counter clockwise rotation. Numerous petrological, mineralogical, geodynamical and tectonic data suggest a relation between this deep structure and near-surface processes. This anomaly sheds light on a number of phenomena including the Cyprus gravity anomaly, counter clockwise rotation of the Mesozoic terrane belt and asymmetry of basins along continental transform faults.

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The East Anatolia–Lesser Caucasus ophiolite: An exceptional case of large-scale obduction, synthesis of data and numerical modelling

Cited by 46 publications

References 140 publications

Early Cretaceous Plume–Ridge Interaction Recorded in the Band-e-Zeyarat Ophiolite (North Makran, Iran): New Constraints from Petrological, Mineral Chemistry, and Geochronological Data

Early Cretaceous Plume–Ridge Interaction Recorded in the Band-e-Zeyarat Ophiolite (North Makran, Iran): New Constraints from Petrological, Mineral Chemistry, and Geochronological Data

Early Cretaceous (Albian) intra‐oceanic subduction in northern branch of Neotethys in NW Iran: Zircon U–Pb geochronology and geochemistry of ophiolitic metagabbros from the Chaldoran area

Combined Multifactor Evidence of a Giant Lower-Mantle Ring Structure below the Eastern Mediterranean

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