气候变化领域集成服务门户(CCPortal): Late Paleoproterozoic granulite-facies metamorphism in the North Altyn Tagh area, southeastern Tarim craton: Pressuretemperature paths, zircon U-Pb ages, and tectonic implications

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DOI	10.1130/B35085.1
	Late Paleoproterozoic granulite-facies metamorphism in the North Altyn Tagh area, southeastern Tarim craton: Pressuretemperature paths, zircon U-Pb ages, and tectonic implications
	Wu H.; Zhu W.; Ge R.
发表日期	2019
ISSN	167606
起始页码	1591
结束页码	1606
卷号	131 期号:2021-09-10
英文摘要	Granulite occupies the root of orogenic belts, and understanding its formation and evolution may provide critical information on orogenic processes. Previous studies have mainly focused on garnet-bearing highpressure and medium-pressure granulites, whereas the metamorphic evolution and pressure-temperature (P-T) paths of garnetabsent, low-pressure granulites are more difficult to constrain. Here, we present zircon U-Pb ages and mineral chemistry for a suite of newly discovered two-pyroxene granulites in the North Altyn Tagh area, southeastern Tarim craton, northwestern China. Conventional geothermobarometry and phase equilibrium modeling revealed that these rocks experienced a peak granulite-facies metamorphism at T = 790-890 °C and P = 8-11 kbar. The mineral compositions and retrograde symplectites record a clockwise cooling and exhumation path, possibly involving near-isothermal decompression followed by near-isobaric cooling. Zircon U-Pb dating yielded a ca. 1.97 Ga metamorphic age, which likely represents the initial cooling age, based on Ti-in-zircon thermometry. Combined with regional geological records, we interpret that these granulites originated from the basement rocks of a late Paleoproterozoic magmatic arc that was subsequently involved in a collisional orogen in the southern Tarim craton, presumably related to the assembly of the Columbia/Nuna supercontinent. The clockwise P-T paths of the granulites record crustal thickening and burial followed by crustal thinning and exhumation in the upper plate of the collisional orogen. Our data indicate that the initial exhumation of this orogen probably occurred no later than ca. 1.97 Ga, which is supported by widespread 1.93-1.85 Ga postorogenic magmatism in this area. © 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/184906
作者单位	State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China
推荐引用方式 GB/T 7714	Wu H.,Zhu W.,Ge R.. Late Paleoproterozoic granulite-facies metamorphism in the North Altyn Tagh area, southeastern Tarim craton: Pressuretemperature paths, zircon U-Pb ages, and tectonic implications[J],2019,131(2021-09-10).
APA	Wu H.,Zhu W.,&Ge R..(2019).Late Paleoproterozoic granulite-facies metamorphism in the North Altyn Tagh area, southeastern Tarim craton: Pressuretemperature paths, zircon U-Pb ages, and tectonic implications.Bulletin of the Geological Society of America,131(2021-09-10).
MLA	Wu H.,et al."Late Paleoproterozoic granulite-facies metamorphism in the North Altyn Tagh area, southeastern Tarim craton: Pressuretemperature paths, zircon U-Pb ages, and tectonic implications".Bulletin of the Geological Society of America 131.2021-09-10(2019).