Petrogenesis and tectonic settings of Carboniferous volcanic rocks from north Zhaosu, western Tianshan Mountains: constraints from petrology and geochemistry.
文献类型:期刊论文
作者 | Qian Qing; Gao Jun; Xiong XianMing; Long LingLi; Huang Dezhi |
刊名 | ACTA PETROLOGICA SINICA
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出版日期 | 2006-05-01 |
卷号 | 22期号:5页码:1307-1323 |
关键词 | Early Carboniferous Dahalajunshan Group Volcanic Rocks Fe-ti Basalts Geochemistry Tectonic Setting Western Tianshan |
ISSN号 | 1000-0569 |
文献子类 | Article |
英文摘要 | Early Carboniferous volcanic rocks from north Zhaosu in western Tianshan Mountains are composed of alkaline olivine basalts and minor tholeiitic basalts. These rocks are characterized with moderate TiO2 (1.10% similar to 1.99%) and P, 0, (0.22% similar to 0.70%) contents, enriched large-ion-lithophile elements (LILE) such as Rb, Ba and K, strongly depleted high-field-strength elements (HFSE) such as Nb, Ta and Ti ((Nb/La)(N) = 0.20 similar to 0.36), as well as fractionated rare earth elements (REE). The geochemical characteristics in general resemble that of the Cenozoic (before middle Miocene) volcanic rocks from Basin and Range, western America, and that of the back-are "transitional" mafic rocks in Central and South America, but are some different from that of typical volcanic arc magma. Abundant inherited zircon of Proterozoic age, and major and trace elemental and neodymium isotopic geochemistry together prove that the magma experienced extensive fractional crystallization and crustal contamination (AFC) before eruption. The tholeiites are likely to be derived from the parental alkaline magma through higher degree of AFC processes, as is inferred from their higher SiO2 contents and K2O/Na2O ratios and lower epsilon(Nd) (t), MgO and Mg-# values relative to the alkaline basalts. Fe-Ti basalts, typically titanium- and iron-rich and silica-poor, occur as thin layer within the alkaline basalts, and are interpreted to be produced from the parental alkaline basalts through moderate to high degree of Fenner trend differentiation. Elemental geoehemistry of the volcanic rocks is attributed to a lithospheric mantle source that had been enriched by subduction fluids. However, occurrence of the Fe-Ti basalts and regularly temporal geochemical variation of the whole volcanic stratum are consistent with a rifting tectonic environment. It is proposed that the volcanic rocks from north Zhaosu were formed in a back-are extensional environment of active continental margin with Proterozoic continental basement. This conclusion also argues against the previous suggestion that the Dahalajunshan group volcanic rocks in western Tianshan Mountains represent continental rift magmatism induced by mantle plume. |
WOS关键词 | CALC-ALKALINE MAGMATISM ; TRACE-ELEMENT ; NORTHWESTERN CHINA ; MINDANAO PHILIPPINES ; PROGRESSIVE CHANGES ; PROPAGATING-RIFT ; NW CHINA ; BASALTS ; BASIN ; EVOLUTION |
WOS研究方向 | Geology |
语种 | 英语 |
WOS记录号 | WOS:000239220600020 |
出版者 | SCIENCE CHINA PRESS |
源URL | [http://ir.iggcas.ac.cn/handle/132A11/66028] ![]() |
专题 | 中国科学院地质与地球物理研究所 |
通讯作者 | Qian Qing |
作者单位 | 1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, Beijing 100029, Peoples R China 2.Cent S Univ, Inst Geol, Changsha 410083, Peoples R China |
推荐引用方式 GB/T 7714 | Qian Qing,Gao Jun,Xiong XianMing,et al. Petrogenesis and tectonic settings of Carboniferous volcanic rocks from north Zhaosu, western Tianshan Mountains: constraints from petrology and geochemistry.[J]. ACTA PETROLOGICA SINICA,2006,22(5):1307-1323. |
APA | Qian Qing,Gao Jun,Xiong XianMing,Long LingLi,&Huang Dezhi.(2006).Petrogenesis and tectonic settings of Carboniferous volcanic rocks from north Zhaosu, western Tianshan Mountains: constraints from petrology and geochemistry..ACTA PETROLOGICA SINICA,22(5),1307-1323. |
MLA | Qian Qing,et al."Petrogenesis and tectonic settings of Carboniferous volcanic rocks from north Zhaosu, western Tianshan Mountains: constraints from petrology and geochemistry.".ACTA PETROLOGICA SINICA 22.5(2006):1307-1323. |
入库方式: OAI收割
来源:地质与地球物理研究所
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