气候变化领域集成服务门户(CCPortal): Early Cenozoic thickening and reworking of the eastern Gangdese arc, south Tibet: constraints from the Oligocene granitoids

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DOI	10.1144/SP474.5
	Early Cenozoic thickening and reworking of the eastern Gangdese arc, south Tibet: constraints from the Oligocene granitoids
	Ding, Huixia; Zhang, Zeming
通讯作者	Zhang, ZM (通讯作者)
发表日期	2018
ISSN	0305-8719
起始页码	291
结束页码	308
卷号	474
英文摘要	The Cenozoic tectonic evolution of the Gangdese arc, formed by juvenile crustal growth during the Mesozoic, remains ambiguous. Here, we conducted a petrological, geochronological and geochemical study of Oligocene ( 32-24 Ma) granitoids with protolith ages of 57-49 and 27 Ma from the eastern Gangdese arc. Geochemically, these rocks are divided into three groups. Group I has high CaO and Sr, and low REE contents, representing plagioclase-rich cumulates. Group II contains relatively high K2O, Pb and REE, and low Na2O contents, and is crystallized from evolved magmas. Group III has relatively high Al2O3 and Sr, and low MgO, Y, Yb, Cr and Ni concentrations, and is thickened lower-crust-derived adakitic rocks. The inherited zircon magmatic cores of these rocks have distinctly different epsilon(Hf(t)) values (-9.88 to + 8.50), whereas the magmatic rims have a narrow range of epsilon(Hf(t)) values (-3.29 to + 5.22). The Hf isotopic homogenization indicates intensive mixing of melts derived from the old and juvenile crustal materials. We concluded that the Cenozoic magmatic or sedimentary rocks were buried into the thickened lower crust and melted to generate the Oligocene granitoids, and that the Gangdese arc experienced lasting Paleogene crustal thickening and reworking.
关键词	ZIRCON U-PB CONTINENTAL COLLISION ZONES HIMALAYAN SYNTAXIS VOLCANIC-ROCKS LOWER CRUST ISOTOPIC CONSTRAINTS TRACE-ELEMENT LHASA TERRANE HF ISOTOPES ULTRAPOTASSIC MAGMATISM
语种	英语
WOS研究方向	Geochemistry & Geophysics ; Geology
WOS类目	Geochemistry & Geophysics ; Geology
WOS记录号	WOS:000473267700014
来源期刊	HP-UHP METAMORPHISM AND TECTONIC EVOLUTION OF OROGENIC BELTS
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/259186
推荐引用方式 GB/T 7714	Ding, Huixia,Zhang, Zeming. Early Cenozoic thickening and reworking of the eastern Gangdese arc, south Tibet: constraints from the Oligocene granitoids[J]. 中国科学院青藏高原研究所,2018,474.
APA	Ding, Huixia,&Zhang, Zeming.(2018).Early Cenozoic thickening and reworking of the eastern Gangdese arc, south Tibet: constraints from the Oligocene granitoids.HP-UHP METAMORPHISM AND TECTONIC EVOLUTION OF OROGENIC BELTS,474.
MLA	Ding, Huixia,et al."Early Cenozoic thickening and reworking of the eastern Gangdese arc, south Tibet: constraints from the Oligocene granitoids".HP-UHP METAMORPHISM AND TECTONIC EVOLUTION OF OROGENIC BELTS 474(2018).