Late Carboniferous adakitic granodiorites in the Qiongkusitai area, western Tianshan, NW China: Implications for partial melting of lower crust in the southern Central Asian Orogenic Belt

	Late Carboniferous adakitic granodiorites in the Qiongkusitai area, western Tianshan, NW China: Implications for partial melting of lower crust in the southern Central Asian Orogenic Belt
	Jiyuan Yin; Wen Chen; Wenjiao Xiao; Chao Yuan; Xiaoping Long; Keda Cai; Bin Zhang
	2016
发表期刊	Journal of Asian Earth Sciences
卷号	124 期号:1 页码:42-54
摘要	Carboniferous granitic rocks are wide spread in the western Tianshan, but their tectonic contexts remain controversial. We present zircon U-Pb age, major element, trace element, and in situ zircon Hf isotopic data for the Qiongkusitai granodiorites from the southern part of the Yili block in the western Tianshan. The granodiorites were emplaced in the Late Carboniferous (ca. 314 Ma) and are characterized by high SiO2 (62.1-65.7 wt.%), high Sr (376-485 ppm), low Y (13.7-17.7 ppm) and low Yb (1.34-1.81 ppm) with Sr/Y ratios of 23-34. Such characteristics imply adakitic affinities. Their low concentrations of Cr (3.85-6.75 ppm), Co (7.63-10.7 ppm) and Ni (2.94-6.80 ppm) suggest little, if any, interaction with a mantle source. Compared to the thickened lower crustal-derived adakitic rocks, the relatively low Nb/Ta ratios of the Qiongkusitai adakitic granodiorites indicate that they were probably generated by partial melting of amphibolite fades rocks, but not eclogite fades rocks. The Qiongkusitai adakitic granodiorites have positive zircon epsilon(Hf(t)) values of +0.7 to +5.1 and T-DM2 of 1.28-1.68 Ga, and they are interpreted as being derived from remelting of amphibolite facies Mesoproterozoic basement with an input of juvenile material. Late Carboniferous magmatism in the western Tianshan was possibly triggered by asthenospheric upwelling as a result of the roll-back of the subducted southern Tianshan oceanic lithosphere.
关键词	Adakitic Granodiorite Slab Roll-back Partial Melting Of Lower Crust West Tianshan Carboniferous
学科领域	矿床地球化学
收录类别	SCI
语种	英语
文献类型	期刊论文
条目标识符	http://ir.gyig.ac.cn/handle/352002/6219
专题	矿床地球化学国家重点实验室_矿床地球化学国家重点实验室_期刊论文
推荐引用方式 GB/T 7714	Jiyuan Yin,Wen Chen,Wenjiao Xiao,et al. Late Carboniferous adakitic granodiorites in the Qiongkusitai area, western Tianshan, NW China: Implications for partial melting of lower crust in the southern Central Asian Orogenic Belt[J]. Journal of Asian Earth Sciences,2016,124(1):42-54.
APA	Jiyuan Yin.,Wen Chen.,Wenjiao Xiao.,Chao Yuan.,Xiaoping Long.,...&Bin Zhang.(2016).Late Carboniferous adakitic granodiorites in the Qiongkusitai area, western Tianshan, NW China: Implications for partial melting of lower crust in the southern Central Asian Orogenic Belt.Journal of Asian Earth Sciences,124(1),42-54.
MLA	Jiyuan Yin,et al."Late Carboniferous adakitic granodiorites in the Qiongkusitai area, western Tianshan, NW China: Implications for partial melting of lower crust in the southern Central Asian Orogenic Belt".Journal of Asian Earth Sciences 124.1(2016):42-54.