摘要
在白龙地区和窝若巴勒地区1∶5万区域地质矿产调查中,根据阿布山组的野外岩石及沉积特征,将阿布山组分为上、下2段,分别为山前河流和湖泊相沉积。该组上段砂岩的地球化学特征显示,物源主要来自上地壳,且主要为长英质岩石。对阿布山组上段的砂岩层进行碎屑锆石采样,从该组的2个样品中得到的最年轻的碎屑锆石年龄分别为85.9Ma和100.39Ma,为该组的时代归属提供了依据。同时,2组样品存在110Ma、440Ma、820Ma、1280Ma四期年龄峰值,结合该组的岩石地球化学特征及物源信息,对羌塘地体的构造演化做了一定的探讨。
From the 1:50000 regional geological and mineral survey of Bailong and Woruobale area, and on the basis of the field rock and sendimentary characteristics, the authors divided the Abushan Formation into two sections, i.e., piedmont alluvial and lacustrine facies clastic sediments. Geochemical characteristics of the sandstone samples from the upper Abushan Formation show that the provenance was mainly from the upper crust, and was mainly felsic rocks. The authors obtained for the first time two detrital zircon samples from Upper Abushan Formation, and the analytical results show that the youngest detrital zircon ages are 85.9Ma and 100.39 Ma. The results provide a basis for determining the ages of Abushan Formation. In addition, there exist four peak ages for the two samples, i.e., 10 Ma, 440 Ma, 820 Ma and 1280 Ma. Combined with the geochemical characteristics and provenance information of this group, the authors made a discussion on the tectonic evolution of Qiangtang terrane.
出处
《地质通报》
CAS
CSCD
北大核心
2017年第7期1188-1203,共16页
Geological Bulletin of China
基金
中国地质调查局项目《西藏窝若巴勒地区1:5万区域地质矿产调查》(编号:1212011221088)和《西藏白龙地区1:5万区域地质矿产调查》(编号:1212011221087)
关键词
阿布山组
羌塘地块
地球化学特征
物源信息
碎屑锆石
Abushan Formation
Qiangtang terrane
geochemical characteristics
provenanace information
detrital zircon