由震源机制和地震波各向异性探讨青藏高原岩石圈变形  

THE DEFORMATION CHARACTERES OF QINGHAI-XIZANG LITHOSPHERE : IMPLICATION FROM EARTHQUAKE MECHANISM AND SEISMIC ANISOTROPY

作　　者：吕庆田[1] 姜枚[1] 马开义[1] 许志琴[2] 

机构地区：[1]中国地质科学院矿床地质研究所 [2]中国地质科学院地质研究所

出　　处：《地质论评》1997年第4期337-346,共10页Geological Review

摘　　要：本文据青藏高原天然地震震源参数和地震波各向异性资料,讨论了高原岩石圈不同圈层的变形特征。指出高原地壳的变形是以周边的逆冲叠覆和内部的东西向拉张和走滑为特征。中、下地壳和上地幔则以北东方向的塑性流动变形为主并呈顺时针旋转。藏南的上地幔盖层则可能发生以正断层为主的脆性变形。最后讨论了上地幔的塑性流动对岩石圈不同圈层变形的影响。认为上地壳东西拉伸和走滑变形与上地幔北东方向的塑性流动密切相关。Based on the earthquake source mechanism and seismic anisotropy, the deformation charac-teres of different tectonic layers of the lithosphere of the Qinghai-Xizang (Tibet) Plateau are discussed in this paper. In the upper crust, east-west crustal extension and strike-slip faulting are the dominant styles of deformation within the plateau, while on the margins of the plateau, thrust faulting and crustal shortening are dominant. The deformation of the middle and low crust show northeast ductile flow and clockwise rotation. Brittle deformation might occur in the uppermost mantle of southern Xizang. Finally, the authors discuss the upper mantle plastic flow and its effect on the deformation of different lithospheric layers of the plateau, and believe that the east-west crustal extension and strike-slip faulting are closely related to the northeast ductile flow of the upper mantle.

关 键 词：青藏高原 震源机制 地震各向异性 岩石圈变形 

分 类 号：P315.3[天文地球—地震学]