The zircon SHRIMP chronology and trace element geochemistry of the   Carboniferous volcanic rocks in western Tianshan Mountains

doi:10.1360/03wd0154

CORC > 北京大学 > 地球与空间科学学院

	The zircon SHRIMP chronology and trace element geochemistry of the Carboniferous volcanic rocks in western Tianshan Mountains
	Zhu, YF ; Zhang, LF ; Gu, LB ; Guo, X ; Zhou, J
刊名	科学通报英文版
	2005
关键词	zircon SHRIMP island arc Dahalajunshan group Xinjiang Western Tianshan Mountains SUBDUCTION ZONES ISLAND-ARC CRUST PETROGENESIS CONSTRAINTS BEHAVIOR MANTLE CHINA
DOI	10.1360/03wd0154
英文摘要	The genesis of the Carboniferous volcanic rocks in the Dahalajunshan group, mainly consisting of trachytes and trachy-andesites and distributing widely in western Tianshan Mountains, remains to be controversial. It has been proposed to be relevant to "rift" or "plume". Detailed petrology and geochemical data presented in this paper show that these volcanic rocks represent typical continental arc magmatism. The volcanic rocks are mainly trachy-andesitic, and the magma source is enriched in LILE, Th and Pb, and depleted in HFSE and Ce. Trace element geochemical study suggests that the basalts could be modeled by 7%-11% partial melt of garnet Iherzolite. The volcanic rocks in the Dahalajunshan group are neither the products of "rift" nor so-called "plume" but represent the continental island arc of the Paleo-Southern Tianshan Ocean. The mantle wedge had been modified by the melt generating in subduction zone during a long evolution history of this island arc. The continental crust materials (i.e. mainly sediment on ocean floor) had been added into island arc through melt in subduction zone. Volcanic rocks occurring in different regions might represent magma eruption in different time. The zircon SHRIMP dating indicates that the ages of the basalt varies between 334.0 Ma and 394.9 Ma. The 13 analyses give an average age of 353.7 +/- 4.5 Ma (MSWD = 1.7). The apparent ages of zircons in trachy-andesite vary between 293.0 Ma and 465.4 Ma. All analyses fall on the U-Pb concordant line and are divided into two groups. 8 analyses produce an average age of 312.8 +/- 4.2 Ma (MSWD = 1.7), which represents the crystallizing age of zircon rims in trachy-andesite. The acquired two ages (i.e. 354 and 313 Ma) belong to the Early Carboniferous and Late Carboniferous epochs, respectively. Thus, the Dahalajunshan group would be separated into several groups with the accumulation of high-quality age dating and data of trace element and isotopic geochemistry, in our opinion.; Multidisciplinary Sciences; SCI(E); 132; ARTICLE; 19; 2201-2212; 50
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/156058]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Zhu, YF,Zhang, LF,Gu, LB,et al. The zircon SHRIMP chronology and trace element geochemistry of the Carboniferous volcanic rocks in western Tianshan Mountains[J]. 科学通报英文版,2005.
APA	Zhu, YF,Zhang, LF,Gu, LB,Guo, X,&Zhou, J.(2005).The zircon SHRIMP chronology and trace element geochemistry of the Carboniferous volcanic rocks in western Tianshan Mountains.科学通报英文版.
MLA	Zhu, YF,et al."The zircon SHRIMP chronology and trace element geochemistry of the Carboniferous volcanic rocks in western Tianshan Mountains".科学通报英文版 (2005).