The Evidence for the Existence of Early Cretaceous Continental Rift in West Qinling Orogenic Belt: the Significance of the Newly Built Maixiushan Group in Tongren Area of Qinghai Province
详细信息
- 责任者：Qi Shengsheng (China University of Geosciences ; Beijing 100083 ; China) ; Deng Jinfu
- 刊名：Geological Bulletin of China
- 出版年：2011
- 卷期：30(11)
- 关键词：早白垩世 ; Lower Cretaceous ; 裂谷作用 ; rifting ; 秦岭 ; Qinling Mountains
- 页码：p.1706-1715
- 图表：2 illus., 15 refs.
- 分类号：0300
- 出版序号：20122188
- issnNo：ISSN1671-2552
- isbnNo：CN11-4648/P
摘要
Based on profile study and regional stratigraphic correlation, the authors newly named this suite of strata Early Cretaceous Maixiushan Group (K1M). According to the angular unconformity between Maixiu shan Group and its overlying and underlying strata, the isotopic ages of volcanic rocks of Duohemao Formation and the insects, estherites and plant fossils in Wanxiu Formation, the authors hold that the Maixiushan Group was formed in Early Cretaceous. Distributed along the nearly NS-trending tensional faulting belt, the Maixiushan Group is of the intracontinental rift facies sedimentation, and the formation of the Maixiushan Group indicated that the West Qinling area entered into a regional extension stage in Early Cretaceous.