Petrological and Geochemical Characteristics of Indosinian Granites in Hongshishan Area , Gansu
详细信息
- 责任者：Huang Zengbao (College of Earth Sciences ; Chengdu University of Technology ; Chengdu 610059 ; China) ; Jin Xia
- 刊名：Northwestern Geology
- 出版年：2011
- 卷期：44(1)
- 关键词：花岗岩 ; granite
- 页码：p.10-19
- 图表：5 illus., 1 table, 27 refs.
- 分类号：0801
- issnNo：ISSN1009-6248
- isbnNo：CN61-1149/P
摘要
The Indosinian granites are located in the ophiolite magmatitic complex of Hongshishan belt, Gansu Province. It consists of three complexes: North Maanshan complex, Xiaocaohu Lake complex, and Hongshishan complex, including granodiorite, tonalite, and syenogranite. They also contain many xenoliths composed by amphibolitie inclusions and dark microgramular mafic inclusions. Its isochronal age is 237.8 to 240 Ma, indicating that the emplacement occurred in Middle Triassic. According to the geological characteristic, petro-chemistry,and geochemistry, these intrusions can be proximately divided into two types: a high-Sr and low-Y (Maanshanbei complex) and a low-Sr and Y type (Xiaocaohu and Hongshishan complex). Therefore, it is suggested that the low-Sr, low-Y type intrusions were generated by partial melting of relatively thick lower crust under high pressure granulite facies conditions with plagioclase to be the dominant residual phase.