气候变化领域集成服务门户(CCPortal): Separating multiple episodes of partial melting in polyorogenic crust: An example from the Haiyangsuo complex, northern Sulu belt, eastern China

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DOI	10.1130/B35210.1
	Separating multiple episodes of partial melting in polyorogenic crust: An example from the Haiyangsuo complex, northern Sulu belt, eastern China
	Feng P.; Wang L.; Brown M.; Wang S.; Li X.
发表日期	2020
ISSN	167606
起始页码	1235
结束页码	1256
卷号	132 期号:2021-05-06
英文摘要	The exotic Haiyangsuo complex is structurally part of the Sulu belt but its contact relationship with surrounding Sulu gneisses is unexposed and therefore unknown, making its affinity uncertain. It comprises gneisses with in-source leucosomes that host minor metabasite bodies; both are cut by leucogranite dikes. In this study, we determine the timing and petrogenesis of leucosomes and leucogranites and assess the tectonic affinity of the complex based on data from gneisses and metabasites. Most zircon from gneisses and leucosomes has oscillatory-zoned cores with CL-bright overgrowth rims, but some has CL-dark cores or mantles between cores and rims. CL-dark and bright zircon yield weighted mean ages of ca. 1817-1812 Ma. CL-dark zircon has flat heavy rare earth element (HREE) patterns and crystallization temperatures of 829-875 °C, suggesting metamorphic growth, whereas rims have steep HREE patterns but a similar range of crystallization temperatures, suggesting growth from anatectic melt; εHf (t = 1813 Ma) of-18.3 to-10.8 indicates a North China Craton source. Magmatic zircon from metabasites yields ages of ca. 825 Ma, similar to those of scattered metabasite occurrences in the North China Craton. Paleoproterozoic zircon cores were scavenged during magma ascent. By contrast, zircon cores from the leucogranites yield concordant dates of 776-701 Ma, consistent with protolith ages in the Sulu belt, whereas overgrowth mantles and rims yield weighted mean ages of ca. 220 Ma and 162 Ma, respectively. Both mantles and rims host multiphase solid inclusions, representing former melt, suggesting anatexis and crystallization of zircon first during initial decompression and then during orogenic collapse of the Sulu belt; whole-rock Nd and Sr isotope compositions implicate the Sulu belt gneisses as the source of these melts. Our interpretation of these data is that the Haiyangsuo complex has an early geologic history similar to the Jiaobei terrane from the southeastern part of the North China Craton and was incorporated into the Sulu belt during Triassic collision of the Yangtze and North China Cratons. The two stages of melting relate to Upper Triassic early exhumation and Upper Jurassic late-stage orogenic collapse, during which the leucogranite magma was derived from a source similar to one elsewhere in the Sulu belt such as the subducted Yangtze Craton and not the North China Craton. This shows that during continental collisions, crust from the upper plate may be dragged into the subduction channel, deformed, and subsequently exhumed in association with partial melting of the crust. © 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/184782
作者单位	State Key Laboratory of Geological Processes and Mineral Resources, and Center for Global Tectonics, School of Earth Sciences, China University of Geosciences, Wuhan, 430074, China; Laboratory for Crustal Petrology, Department of Geology, University of Maryland, College Park, MD 20742, United States; College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao, 266590, China
推荐引用方式 GB/T 7714	Feng P.,Wang L.,Brown M.,et al. Separating multiple episodes of partial melting in polyorogenic crust: An example from the Haiyangsuo complex, northern Sulu belt, eastern China[J],2020,132(2021-05-06).
APA	Feng P.,Wang L.,Brown M.,Wang S.,&Li X..(2020).Separating multiple episodes of partial melting in polyorogenic crust: An example from the Haiyangsuo complex, northern Sulu belt, eastern China.Bulletin of the Geological Society of America,132(2021-05-06).
MLA	Feng P.,et al."Separating multiple episodes of partial melting in polyorogenic crust: An example from the Haiyangsuo complex, northern Sulu belt, eastern China".Bulletin of the Geological Society of America 132.2021-05-06(2020).