气候变化领域集成服务门户(CCPortal): Petrogenesis of Ordovician Granitoids in Western Kunlun, NW Tibetan Plateau: Insights into the Evolution of the Proto-Tethys Ocean

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DOI	10.1130/B35740.1
	Petrogenesis of Ordovician Granitoids in Western Kunlun, NW Tibetan Plateau: Insights into the Evolution of the Proto-Tethys Ocean
	Wang P.; Zhao G.; Han Y.; Liu Q.; Yao J.; Li J.
发表日期	2021
ISSN	167606
起始页码	1071
结束页码	1089
卷号	133
英文摘要	Granitoid rocks are universal in continental crust and are of special significance in understanding tectonic settings. This paper presents detailed zircon U-Pb dating, Hf isotope, whole-rock geochemistry, and SrNd-Pb isotope analyses, and mineralogy of two Ordovician granitoid intrusions and one quartz diorite intrusion in Western Kunlun, NW Tibetan Plateau. The Yutian Complex is composed of diverse rock suites, including monzogabbros, quartz monzodiorites, monzogranites, and monzodioritic enclaves. These suites have similar rock formation ages (447–440 Ma) and minerals, e.g., amphibole grains from different suites belonging to pargasite. Moreover, they exhibit geochemical similarities, such as broadly parallel traceelement patterns characterized by enrichments in light rare earth elements and large ion lithophile elements, and depletions in high field strength elements, which are typical features of arc rocks. Furthermore, the studied samples display homogeneous zircon Hf values, e.g., εHf(t) = −1 to −3, and wholerock isotopic compositions, e.g., εNd(t) = −4 to −6. Thus, they were most likely derived from a mantle wedge enriched by subducted sediments and fluids, which then evolved into different suites through fractional crystallization of hornblende and plagioclase. The ca. 440 Ma North Yutian quartz diorite intrusion, with an average of εHf(t) value of −6, was a product of the partial melting of mafic lower crust through slightly fractional crystallization of hornblende. In contrast, the ca. 470 Ma Aqiang granodiorite intrusion has εHf(t) values varying from −5 and −2, but it has heterogeneous petrological and geochemical features. It is considered to be a product of the partial melting of the overriding mantle wedge modified by fluids derived from the subducted Proto-Tethys slab and some mixed crustal materials. The Aqiang samples belong to the slightly fractionated I-type series, but they have variable alumina saturation index (ASI = molar Al2O3/ [CaO – 3.33 × P2O5+ Na2O + K2O]) values (0.74–1.03) due to variable peraluminous biotite contents. The different suites in the Yutian Complex display low ASI values (<1) controlled by sources and fractional crystallization. The Yutian Complex and the North Yutian intrusion were emplaced during the southward subduction of the Proto-Tethys oceanic lithosphere, and the Aqiang intrusion was emplaced in response to the northward subduction. © 2020 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/184669
作者单位	Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China; State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Northern Taibai Street 229, Xi’an, 710069, China; Graduate School of Life and Environmental Sciences, The University of Tsukuba, Ibaraki, 305-8572, Japan; Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing, 100081, China
推荐引用方式 GB/T 7714	Wang P.,Zhao G.,Han Y.,et al. Petrogenesis of Ordovician Granitoids in Western Kunlun, NW Tibetan Plateau: Insights into the Evolution of the Proto-Tethys Ocean[J],2021,133.
APA	Wang P.,Zhao G.,Han Y.,Liu Q.,Yao J.,&Li J..(2021).Petrogenesis of Ordovician Granitoids in Western Kunlun, NW Tibetan Plateau: Insights into the Evolution of the Proto-Tethys Ocean.Bulletin of the Geological Society of America,133.
MLA	Wang P.,et al."Petrogenesis of Ordovician Granitoids in Western Kunlun, NW Tibetan Plateau: Insights into the Evolution of the Proto-Tethys Ocean".Bulletin of the Geological Society of America 133(2021).