| 摘要: |
| 麦嘎盆地属典型的山间断陷盆地,其形成演化发展又受制于盆周的断层构造活动。麦嘎古湖的形成演化发展及消亡与麦嘎盆地的发展演化紧密相连。笔者从构造和湖积物特征入手,对麦嘎古湖的形成演化发展消亡作了深入探讨,认为其受到新构造活动、古气候、河流侵蚀等自然外力的综合作用,麦嘎盆地先后经历了河流※湖沼※河流※湖沼※湖泊※湖沼※湖泊※河流的演化过程。 |
| 关键词: 麦嘎盆地 古湖 形成演化 西藏 |
| DOI： |
| 附件 |
| 投稿时间：2004-05-08 |
| 基金项目:中国地质调查局“1:25万《措勤区幅》区域地质调查”。 |
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| The formation and evolution of the Mega ancient lake in the middle part of the Gangdise Mountain Ranges, Xizang |
| LI Jian-bing, JIANG Yuan-sheng, ZHU Shi-hua, ZHANG Kuan-zhong |
(1. Chengdu University of Technology, Chengdu 610059, Sichuan, China;
2. Sichuan Institute of Geological Survey, Chengdu 610213, Sichuan, China) |
| Abstract: |
| The Mega Basin is a typical intermountain fault basin constained by the faulting around the basin. The study of the Mega ancient lake shows that the formation, development and collapse of the lake are closely related to those of the Mega Basin. The faulting, northern and southern differential uplifting, palaeoclimatic changes and fluvial erosion from the Holocene onwards resulted in the evolution of the basin according to the evolutionary path of river-swamp-river-swamp-lake-swamp-lake-river. The Mega ancient lake has a total thickness of sediments of 20.5 m and an average depositional rate of more than 2.81 mm/a, which are much higher than those of the middle Pleistocene Lanong Lake in the same area. This implies that for the Mega Basin, the subsidence rates during the Holocene are much higher than those during the middle Pleistocene. |
| Key words: Mega Basin ancient lake formation and evolution Xizang |
