气候变化领域集成服务门户(CCPortal): Subduction initiation and back-arc opening north of Neo-Tethys: Evidence from the Late Cretaceous Torbat-e-Heydarieh ophiolite of NE Iran

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DOI	10.1130/B35065.1
	Subduction initiation and back-arc opening north of Neo-Tethys: Evidence from the Late Cretaceous Torbat-e-Heydarieh ophiolite of NE Iran
	Moghadam H.S.; Stern R.J.; Griffin W.L.; Khedr M.Z.; Kirchenbaur M.; Ottley C.J.; Whattam S.A.; Kimura J.-I.; Ghorbani G.; Gain S.; O'Reilly S.Y.; Tamura A.
发表日期	2020
ISSN	167606
起始页码	1083
结束页码	1105
卷号	132 期号:2021-05-06
英文摘要	How new subduction zones form is an ongoing scientific question with key implications for our understanding of how this process influences the behavior of the overriding plate. Here we focus on the effects of a Late Cretaceous subduction-initiation (SI) event in Iran and show how SI caused enough extension to open a back-arc basin in NE Iran. The Late Cretaceous Torbat-e-Heydarieh ophiolite (THO) is well exposed as part of the Sabzevar-Torbat-e-Heydarieh ophiolite belt. It is dominated by mantle peridotite, with a thin crustal sequence. The THO mantle sequence consists of harzburgite, clinopyroxene-harzburgite, plagioclase lherzolite, impregnated lherzolite, and dunite. Spinel in THO mantle peridotites show variable Cr# (10-63), similar to both abyssal and fore-arc peridotites. The igneous rocks (gabbros and dikes intruding mantle peridotite, pillowed and massive lavas, amphibole gabbros, plagiogranites and associated diorites, and diabase dikes) display rare earth element patterns similar to MORB, arc tholeiite and back-arc basin basalt. Zircons from six samples, including plagiogranites and dikes within mantle peridotite, yield U-Pb ages of ca. 99-92 Ma, indicating that the THO formed during the Late Cretaceous and was magmatically active for ∼7 m.y. THO igneous rocks have variable εNd(t) of +5.7 to +8.2 and εHf(t) ranging from +14.9 to +21.5; zircons have εHf(t) of +8.1 to +18.5. These isotopic compositions indicate that the THO rocks were derived from an isotopically depleted mantle source similar to that of the Indian Ocean, which was slightly affected by the recycling of subducted sediments. We conclude that the THO and other Sabzevar-Torbat-e-Heydarieh ophiolites formed in a back-arc basin well to the north of the Late Cretaceous fore-arc, now represented by the Zagros ophiolites, testifying that a broad region of Iran was affected by upper-plate extension accompanying Late Cretaceous subduction initiation. © 2019 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184780
作者单位	School of Earth Sciences, Damghan University, Damghan, 36716-41167, Iran; ARC Centre of Excellence for Core to Crust Fluid Systems and GEMOC ARC National Key Centre, Department of Earth and Planetary Sciences, Macquarie UniversityNSW 2109, Australia; Geosciences Department, University of Texas at Dallas, Richardson, TX 75083-0688, United States; Department of Geology, Kafrelsheikh University, Kafr Elsheikh, 33516, Egypt; Institut für Mineralogie, Leibniz Universität Hannover, Germany; Universitat zu Koln, Koln, 50674, Germany; Department of Earth Sciences, Northern Centre for Isotopic and Elemental Tracing, University of Durham, Durham, DH1 3LE, United Kingdom; Department of Geosciences, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia; Department of Solid Earth Geochemistry, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Natsushima-Cho 2-15, Yokosuka, 237-0061, Japan; Department of Earth Sciences, Kanazawa University, Ishikawa, 920-1192, Japan
推荐引用方式 GB/T 7714	Moghadam H.S.,Stern R.J.,Griffin W.L.,et al. Subduction initiation and back-arc opening north of Neo-Tethys: Evidence from the Late Cretaceous Torbat-e-Heydarieh ophiolite of NE Iran[J],2020,132(2021-05-06).
APA	Moghadam H.S..,Stern R.J..,Griffin W.L..,Khedr M.Z..,Kirchenbaur M..,...&Tamura A..(2020).Subduction initiation and back-arc opening north of Neo-Tethys: Evidence from the Late Cretaceous Torbat-e-Heydarieh ophiolite of NE Iran.Bulletin of the Geological Society of America,132(2021-05-06).
MLA	Moghadam H.S.,et al."Subduction initiation and back-arc opening north of Neo-Tethys: Evidence from the Late Cretaceous Torbat-e-Heydarieh ophiolite of NE Iran".Bulletin of the Geological Society of America 132.2021-05-06(2020).