地质学报2011，Vol.85Issue(1)：34-55,22.
青藏高原东北部基底卷入型褶皱的形成机制探讨—以西宁盆地小峡背斜为例
Mechanism of Basement-Involved Folds in the Northeastern Qinghai-Tibetan Plateau: A Case Study of the Xiaoxia Anticline in the Xining Basin
摘要
Abstract
The Xiaoxia anticline of the northeastern Qinghai-Tibetan Plateau is one basement-involved fold forming during the Cenozoic. This study shows that the formation of the anticline underwent at least three deformation events. Due to the Indo-Eurasian collision in the Early Cenozoic (～49Ma), the Xining basin rotated clockwise. And the early northwest-southeast trending faults developed within the basement and new-born faults started to move right-laterally, which resulted in the development of the northwestsoutheast trending folding of cover layers. The deformation of the basement and sedimentary layers is similar to that of Trishear model. During the Middle-late Cenozoic (49～5Ma), the intensive left-lateral strike-slipping of the north and south margins of the Xining basin resulted in NNE-trending faulting of the basin basement and new-born R' fault activity, which gave rise to the formation of current Xiaoxia anticline. Structural analysis shows that these NNE-trending penetrative faults made the basement show some characteristics of ductile deformation macroscopically, with faulting mainly in the basement and passive folding deformation in the cap rock. The formation of the Xiaoxia anticline shows that the development of early faults in the basement is one of the important factors controlling the basement-cored folds, and the thickening of the lower crust of the plateau may be related to the development of the basement-involved fold.关键词
小峡/基底卷入型褶皱/厚皮构造/青藏高原/斜冲断层Key words
Xiaoxia Gouge/ basement-involved fold/ thick-skinned structure / Qinghai-Tibetan Plateau /oblique thrust fault引用本文复制引用
张进,马宗晋,程鸿毅,李岩峰,任文军..青藏高原东北部基底卷入型褶皱的形成机制探讨—以西宁盆地小峡背斜为例[J].地质学报,2011,85(1):34-55,22.基金项目
本文为中国地震局地质研究所中央级公益性科研院所基本科研业务专项(JB-07-20)资助的成果. （JB-07-20）
