气候变化领域集成服务门户(CCPortal): Conditions and timing of incorporation of ophiolite into orogenic crust during oblique convergence; Central Anatolia

CCPortal

DOI	10.1007/s00531-020-01908-7
	Conditions and timing of incorporation of ophiolite into orogenic crust during oblique convergence; Central Anatolia
	Radwany M.; Morgan L.E.; Whitney D.L.
发表日期	2020
ISSN	14373254
起始页码	2393
结束页码	2406
卷号	109 期号:7
英文摘要	Ophiolitic fragments scattered over a wide area of Central Anatolia exhibit varying degrees of metamorphism, from unmetamorphosed to upper amphibolite facies, although geochemical similarities suggest they are all part of the Central Anatolian Ophiolite (CAO). Magmatic crystallization of oceanic crust in the CAO at ~ 91 Ma coincided with high-grade metamorphism of rocks that underlie the southern, highest grade part of the CAO, raising questions about the tectonic relationship of the ophiolite to underlying metasedimentary and plutonic rocks. New geochronology results show that the 40Ar/39Ar hornblende age of amphibolite-facies metagabbro in the high-grade metamorphic part of the CAO is ~ 87 Ma, similar to hornblende ages from amphibolite in the underlying Niğde metamorphic/plutonic massif. Biotite in a deformed quartzofeldspathic rock associated with high-grade meta-ophiolitic rocks yielded an 40Ar–39Ar age of ~ 78 Ma, similar to biotite ages from the Niğde Massif. Hornblende in gabbro from unmetamorphosed CAO yielded an older 40Ar/39Ar age of ~ 90 Ma, similar to the previously determined crystallization age of the ophiolite. These data indicate that the southern part of the ophiolite was incorporated into and therefore metamorphosed and deformed with the orogenic mid-crust now exposed in the Niğde metamorphic–plutonic complex, whereas the northern, unmetamorphosed part of the ophiolite was obducted onto the continent. This distinct difference in different parts of the ophiolite may indicate oblique collision or irregularities in the continental margin, resulting in part of the ophiolite being incorporated into the orogenic crust and subsequently exhumed and cooled with it, and another part being obducted. © 2020, Geologische Vereinigung e.V. (GV).
英文关键词	Central Anatolia; Metaophiolite; Nigde Massif
语种	英语
scopus关键词	amphibolite facies; metagabbro; metamorphism; obduction; oblique fault; ophiolite; orogeny; tectonic evolution; tectonic setting; Anatolia; Nigde; Turkey
来源期刊	International Journal of Earth Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/147624
作者单位	Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN 55455, United States; Department of Mining and Geological Engineering, University of Arizona, Tucson, AZ 85721, United States; U.S. Geological Survey, Denver, CO, United States
推荐引用方式 GB/T 7714	Radwany M.,Morgan L.E.,Whitney D.L.. Conditions and timing of incorporation of ophiolite into orogenic crust during oblique convergence; Central Anatolia[J],2020,109(7).
APA	Radwany M.,Morgan L.E.,&Whitney D.L..(2020).Conditions and timing of incorporation of ophiolite into orogenic crust during oblique convergence; Central Anatolia.International Journal of Earth Sciences,109(7).
MLA	Radwany M.,et al."Conditions and timing of incorporation of ophiolite into orogenic crust during oblique convergence; Central Anatolia".International Journal of Earth Sciences 109.7(2020).