【摘要】 全球最新、规模最大的青藏高原造山带是研究陆陆汇聚、板块俯冲和高原隆升等大陆动力学问题的天然实验室。自20世纪50年代至今,已经积累大量被动源地震观测和主动源地震探测资料用于揭示青藏高原的地壳与上地幔结构,勾勒出青藏高原的壳幔结构的基本特征。本文在汇总前人工作基础上,通过对深地震测深、深地震反射剖面和宽频地震观测三种地震方法资料的梳理,探讨青藏高原的莫霍面深度及其分布特征。结果表明,青藏高原莫霍面形态复杂,深度变化很大,分布总体特征呈现出中间浅,南部较深,北部较浅,西部较深,东部较浅的趋势,最深的和最浅的莫霍面可以相差40km。这种变化趋势记录了印度板块和欧亚板块的相互作用使高原地壳增厚、减薄过程,并驱使地壳物质由西向东流动。更多还原

【Abstract】 The Qinghai-Tibet plateau is the newest and biggest orogenic belt in the world and can serve as a natural laboratory for studying such aspects of continental geodynamics as continent-continent collision,convergence,subduction and plateau uplift.From the 1950s to the present,lots of active-source(deep seismic sounding and deep seismic reflection profiling) and passive-source seismic detection(broadband seismic observation) researches have been carried out to reveal the crust-mantle structure.In this paper,the authors have mainly summarized three seismic detection methods for revealing the Moho depth of the Qinghai-Tibet plateau based on previous achievements.The results show that the Moho of the Qinghai-Tibet plateau is very complex and its depth varies from place to place,and that the Moho is on the whole deeper beneath the south than beneath the north and deeper in the west than in the east.It is also revealed that the Moho in the Qiangtang terrane,the hinterland of the Qinghai-Tibet plateau,is shallower than that on both the southern and the northern sides of the Qinghai-Tibet plateau,and that the deepest Moho is 40 km deeper than the shallowest Moho.Such a trend has recorded the crustal thickening and thinning caused by the mutual response between the India plate and the Eurasia plate as well as the eastward mass flow in the Qinghai-Tibet plateau.更多还原