| 青藏高原第四纪大陆冰盖与高原隆升——试论青藏高原第四纪大陆冰盖的地壳均衡过程 |
| 点此下载全文 |
| 引用本文：韩同林,郑英龙,唐哲明.1990.青藏高原第四纪大陆冰盖与高原隆升——试论青藏高原第四纪大陆冰盖的地壳均衡过程[J].地球学报,11(2):107-120. |
| DOI： |
| 摘要点击次数: 2023 |
| 全文下载次数: 2320 |
|
|
| 中文摘要:内容提要青藏高原第四纪大陆冰盖属于统一的海洋性大陆冰川，冰盖面积达数百万平方公里，冰盖中心大约位于西藏中部，北纬32°—35°,东经81°—89°左右。冰盖大约形成于早更新世中期，冰盖冰流厚约900—1700 m以上，冰盖形成时的古雪线的海拨高度约1300—1800 m。由于大陆冰盖发育和消融，高原地壳的均衡过程十分明显，使高原当时的隆升速度明显减慢或加快。但对高原隆升的总幅度影响不大。 |
| |
| THE QUATERNARY CONTINENTAL GLACIAL SHEET IN QINGHAI-XIZANG PLATEAU AND THE UPLIFT OF THE PLATEAU——A STUDY ON THE CRUST ISOSTASY PROCCESS IN QINGHAI-XIZANG PLATEAU CAUSED BY THE QUATERNARY CONTINENTAL |
|
|
| Abstract:The Quaternary continental glacial sheet belongs to a united oceanic continental glacier. Formed in the middle of Early Pleistocene, its center is located at the cental part of Xizang (Tibet) Autonomous Region at N 32°—35° and E 81°—89°. The ice flow near the center of the Sheet is radial but in all other area it is mainly from west to east. The thickness of the ice flow is about 900—1700 meters. The palaeosnowline in the time when the glacial sheet formed was about 1300—1700 meters above the sea level. The crust isostasy caused by the continental glacial sheet is quite obvious. It is shown by mathematics imitation with the model of bent elastic plate that the maximum of the lithosphere bend is about 610 meters when the ice flow of the glacial sheet is 1500 meters thick, and the maximum of that is 410 meters and 210 meters respectively when the ice flow is 1000 meters and 500 meters thick. Due to the development of continental glacial sheet, the uplifting rate of the plateau slowed down obviously for isostasy, from 1.4 mm/a, the average rate, down to 0.7 mm/a. With the melting of the continental glacial sheet, the uplifting rate of the plateau speeds up greatly from 1.4mm/a up to 2.4mm/a, but the total extent of the plateau uplift was not evidently affected.The main geological evidence for the crust isotasy caused by the development and melt of the continental glacial sheet is that the related sediments become thicker and coarser upwards. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
|
|
|
|
|
