摘要
西藏羌塘盆地可分为北羌塘坳陷、中央隆起带和南羌塘坳陷 3个二级构造单元。在早及中三叠世 ,羌塘盆地具相似的岩相古地理格局 ,北羌塘坳陷受可可西里—巴颜喀拉海槽的海侵作用 ,表现为陆表海沉积 ,而南羌塘坳陷和中央隆起带此时处于剥蚀环境。至晚三叠世 ,受班公湖—怒江洋扩张作用的影响 ,除中央隆起带西段继续遭受剥蚀外 ,羌塘盆地普遍接受沉积。南北羌塘水域虽经双湖海峡连为一体 ,但盆地性质发生根本性变化 ,构造岩相组合也明显不同。南羌塘盆地为班公湖—怒江洋北侧的扩张边缘海盆 ,而北羌塘则是可可西里—巴颜喀拉造山作用下的前陆盆地。羌塘盆地三叠纪岩相古地理具有“东西呈带 ,带中分块”的格局 。
Qiangtang Basin can be divided into Northern Qiangtang Depression,the Center Uplift and Southern Qiangtang Depression. During the early and middle Triassic, Qiangtang Basin had the same framework of lithofacies and palaeogeography. Affected by marine transgression of Kekexili-Bayankala ocean trough, the Northern Qiangtang Depression deposited epicontinental sea sediments. At the same time, the Southern Qiangtang Depression and the Center Uplift were being denuded. Till to the Late Triassic, except the west part of the Center Uplift, the Qiangtang Basin was covered with water owing to the spreading of Bangonghu-Nujiang Ocean. Although the Northern Qiangtang Basin and Southern Qiangtang Basin were connected through Shuanghu strait, the origins of them were different, and their components of the tectonic and lithofacies were also different. The Southern Qiangtang Basin was an extensional marginal basin to the north of Bangonghu-Nujiang ocean, while the Northern Qiangtang Basin showed the character of foreland basin affected by Kekexili-Bayankala orogenic movement. The framework of lithofacies and palaeogeography had the feature of 'zonation along EW,blocks in zones', which was resulted from the regional tectonic evolution and basal faulting.
出处
《古地理学报》
CAS
CSCD
2002年第4期9-18,共10页
Journal of Palaeogeography：Chinese Edition
基金
中国石油天然气集团公司"九五"科技工程项目 (QZ72 0 41 0 2 )资助
关键词
三叠纪
岩相古地理
构造控制
羌塘盆地
造山途径
Triassic, lithofacies palaeogeography, tectonic control, Qiangtang Basin
