- 责任者：Luo Yong (City Key Laboratory of Dushan Jade ; Nanyang Normal University ; Nanyang 473061 ; China) ; Shan Qiang
- 刊名：Geochimica
- 出版年：2013
- 卷期：42(6)
- 关键词：火山岩 ; volcanic rocks ; 基性岩 ; basic rocks ; 新疆 ; Xinjiang
- 页码：p.544-556
- 图表：11 illus., 2 tables, 61 refs.
- 分类号：0801
- issnNo：ISSN0379-1726
- isbnNo：CN44-1398/P
Awulale Mountians, located in Yili terrane in north Xinjiang, is an important part of Central Asian Orogenic Belt. This paper focuses on the major, trace elements and isotope geochemistry characteristic of the Permain potassic mafic volcanic rocks, which are widely distributed in the western part of the Awulale Mountains （Qiongbulake, Kachakerang and Tobasisayi）. We propose that： （1） The mafic volcanic rocks in the western part of Awulale Mountains are shoshonite. The potassic mafic volcanic rocks experienced a considerable degree of differentiation and evolution with iron magnesium index ranging from 23.3 to 64.1. （2） Element geochemistry shows that, the Lower Permian potassic mafic volcanic rocks formed in post-collisional arc environment in the western part of the Awulale Mountains. These suggest that the geodynamic regime of this region changed from compression to extension in the Early Permian. Tracce element patterns as well as La/Yb and Nb/Y ratios show significant enrichment in large ion lithophile elements and depletion in high field elements, e.g., Nb, Ta, Ti, suggesting strong influence from plate subduction. This studies also show, Awulale potassic mafic volcanic source region also contains a certain amount of hydrous minerals amphibole or phlogopite, in addition to spinel, pyroxene, olivine, and a small amount of garnet, i.e., primitive magmas formed in spinel peridotite and garnet peridotite transition zone at depths greater than 70 km. （3） The trace element geochemistry show that, potassic mafic volcanic rocks in the north and south of the western part of the Awulale Mountains source region are significantly different： the southern Tobasisayi potassic mafic volcanic rocks were more water-rich compared to the northern Kachakerang and Qiongbulake, indicating more influence from plate subduction.