| 摘要: |
| 着重调查了以阿坝盆地为代表的青藏高原东缘新生代盆地的形成演化及其环境变化,新建立了若干生物组合;对第四纪冰川堆积物进行了比较细致的研究,初步建立了气候地层单位;首次于壤塘县曼迪乡上三叠统侏倭组的滑塌堆积层中,采获异地埋葬珊瑚群化石,建立三叠纪双壳类两个生物带;调查了侏倭组、新都桥组、如年各组3个岩石地层单元基本层序、剖面韵律结构及沉积构造;获得若末柯火山岩和小石头山花岗岩Rb-Sr等时线年龄。 |
| 关键词: 1:25万 地质调查 色达县幅 阿坝县幅 成果与进展 四川 青海 |
| DOI： |
| 附件 |
| 投稿时间：2004-12-10 |
| 基金项目: |
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| 1:250000 Sertar and Aba Sheets in northwestern Sichuan and southeastern Qinghai |
| Sichuan Institute of Geological Survey |
| (Sichuan Institute of Geological Survey, Chengdu 610081, Sichuan, China) |
| Abstract: |
| Exemplified by the Aba Basin, the emphasis is placed on the evolution and environmental changes of the Cenozoic basins in northwestern Sichuan and southeastern Qinghai on the eastern margin of the Qinghai-Xizang Plateau. A number of biologic assemblages are established. The Quaternary glacial deposits are treated in detail, and the climato-stratigraphic units are tentatively constructed. The allopatric coral fossils are collected in the olistostromes of the Upper Triassic Zhuwo Formation in Mandi, Zamtang, and two biozones of Triassic bivalves are established. The sequences, rhythmic section structures and sedimentary structures are examined for three lithostratigraphic units such as the Zhuwo, Xinduqiao and Runian Formations. The Rb-Sr isochron ages are determined for the Ruomoke volcanic rocks (214±1 Ma) and Xiaoshitoushan granites (244±1 Ma). |
| Key words: 1:250 000 geological survey Sertar Sheet Aba Sheet development Sichuan Qinghai |
