青藏高原北缘深部地壳结构特征及其形成机制探讨  

The Crustal Structure of the Northern Margin of Qinghai-Tibet Plateau and Its Genetic Analysis

作　　者：王泽利[1] 何樵登[2] 孟令顺[2] 

机构地区：[1]长春工程学院地质与测绘工程系,吉林长春130021 [2]吉林大学地球探测科学与技术学院,吉林长春130026

出　　处：《世界地质》2002年第2期105-110,共6页World Geology

摘　　要：柴达木盆地 -祁连山地区位于青藏高原北缘 ,同青藏高原主体一样 ,该区具有多层地壳结构特征 ,并普遍出现壳内低速层 ,地壳厚度是华北及华南地区的 2倍以上。其形成可能与地壳的横向挤压缩短及幔源物质的底侵作用有关。随着底侵作用增强 ,地壳厚度加大 ,岩石圈厚度则越趋于减薄 ,地壳上部表现为拉张 ,下部发生壳幔深熔及幔源流体的交代作用 ,从而导致了地壳低速层、地热和浅源地震的发育。同时 。Qaidam basin-Qilian mountain is situated on the north margin of Qinghai-Tibet plateau. Like the main part of the plateau, there commonly exist a muti layer crustal structure and the low velocity layers. The crust thickness of the region is twice more than that of northern and southern China. It may be caused by the transverse compressive shortening and the upper mantle underplating .With the crust underplating getting strong, the thickness of the crust increase , and the lithospheric thickness tend to decrease. A tension condition in the upper crust and the deep melting or the mantle derived fluid replacement in the lower crust exist, which bring on the low velocity layers,terrestrial heat and shallow earthquake in the crust . It is also the reason showing hot crust and cold mantle in Qinghai-Tibet plateau region.

关 键 词：青藏高原北缘 地壳结构 低速层 底侵作用 

分 类 号：P631.4[天文地球—地质矿产勘探] P542.3[天文地球—地质学]