Chronology, Geochemistry and Petrogenesis for Nyainqentanglha Intermediate-Basic Intrusive Rocks
详细信息
- 责任者：Chen Xiaofeng (Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Zhu Lixin
- 刊名：Journal of Jilin University
- 出版年：2012
- 卷期：42(1)
- 关键词：侵入体 ; intrusions ; 念青唐古拉山 ; Nyainqentanglha Range
- 页码：p.112-125
- 图表：11 illus., 2 tables, 47 refs.
- 分类号：0801
- issnNo：ISSN1671-5888
- isbnNo：CN22-1343/P
摘要
Nyainqentanglha Early Eocene intermediate-basic intrusive rocks consist of amphibole gabbro and monzodiorite. The zircon LA-MC-ICPMS U-Pb dating for the amphibole gabbro defines a crystallizationage of (49.92±0.24) Ma. The intermediate-basic intrusive rocks are high-K calc-alkaline to shoshonite series based on the SiO2-K2O diagram. Analysis indicates that they come from an enriched mantle metasomatized by ancient continental crust. REE simulation suggests that the forming processes for the intermediate-basic intrusive rocks were controlled by low tomoderate partial melting of the enriched mantle. The dynamic background for the intermediate-basic intrusive rocks are likely linked to breakoff of Neo-Tethyan slab followed by upwelling of asthenospheric materials from the slab window.