Geochemical and Sr-Nd Isotopic Study on Permian Basalts from Danba Area, Songpan-Ganze Terrane: Petrogenesis and Tectonic Implication

详细信息   

• 责任者：Zi Jianwei (Guangzhou Institute of Geochemistry ; Chinese Academy of Sciences ; Guangzhou 510640 ; China) ; Fan Weiming
• 刊名：Geotectonica et Metallogenia
• 出版年：2008
• 卷期：32(2)
• 关键词：玄武岩 ; basalts ; 构造环境 ; tectonic setting ; 四川 ; Sichuan
• 页码：p.226-237
• 图表：11 illus., 2 tables, 42 refs.
• 分类号：0801
• issnNo：ISSN1001-1552
• isbnNo：CN43-1595/P

摘要

The Permian marine basahs at the Danba, Songpan-Ganze terrane, are located to the west of the Longmenshan fault in northwestern Sichuan Province. These basalts are characterized by high-Ti tholeiites,which?? have high TiO2 contents and Ti/Y ratios. And they have OIB-type incompatible elemental ratios and REE and spidergram patterns. Based on the petrographies??, major and trace elemental and isotopic geochemistry, the Danba Permian basalts are virtually part of the Emeishan large igneous province (ELIP), which were formed by mantle plume activity at -260 Ma. These suggest that ELIP occurs beyond the Yangtze Craton and extends to Songpan-Ganze terrane. Furthermore, the temporal and spatial coincidence between ELIP basalt eruption and rifting of the Yangtze Craton, together with kilometer-scale regional doming prior to eruption, implys?? that continental breakup might be a shallow response to the Emeishan plume.