中文摘要：

从现今地质构造组成出发,结合地震活动特征,总结了近年来中亚大三角地震构造域东边界北段（南北地震带北段和蒙古中部）主要活动断层的研究成果。认为中亚大三角东边界北段的现今地质构成实质是一系列大型走滑断裂构造的尾端构造与侧向断层,或者是夹持于左旋走滑断裂带之间的张扭性地堑断裂系,包括：六盘山弧形断裂带、桌子山-贺兰山断裂系、狼山-色尔腾山前断裂系、达兰扎达嘎德断裂系、莫高德断裂系、库苏古尔裂谷系。中亚大三角东边界北段地震构造是在印度-欧亚板块碰撞和局部上地幔物质流动或显著地幔各向异性所控制的现今区域应力场条件下,沿大型走滑断裂带两侧或尾端不同方向的先存断裂的重新活动。

英文摘要：

The recent researches of active faults related to the north segment of the eastern boundary of GTSR （the great triangular seismotectonic region of Central Asia） , including the north part of the North-South Seismic Belt and central Mongolia,are summarized based on their geological background and seismic activities at present. The north segment of the eastern boundary of the GTSR is composed by a series of terminal structures,lateral structures of large sinistral strike-slip faults, and transtension- al graben fault systems between the large sinistral strike-slip faults. From south to north,the fault sys- tems,which compose the north segment of the eastern boundary of GTSR, include ： （ 1 ） Liupanshan ar- cuate fault zone, which is the eastern terminal compression structure of the Haiyuan Fault zone and Zhongwei-Tongxin Fault zone; （2）Zhuozishan-Helanshan Fault system, which is a transtensional gra- ben fault systems between the Zhongwei-Tongxin Fault zone and the Yabulaishan-Bayanxiboshan Fault zone; （3）Langshan-Sertengshan piedmont fault system, which is the eastern relaxing structure of the Yabulaishan-Bayanxiboshan Fault zone; （4）Dalandzadgad Fault system, which is the eastern termi- nal compression structures of the Gobi-Tienshan Fault zone and Gobi-Altay Fault zone; （5） Mogod Faults system,the possible eastern terminal compressional structures of the North Hangay Fault zone; and （6）Hovsgol rift system, which is the extensional lateral structures of the Tunka Fault zone. The nature of the seismic structures of the north segment of the eastern boundary of the GTSR is the re-ac- tivation of the pre-existing faults that locate beside or on the terminations of giant strike-slip fault zones in the present regional stress field, controlled by the northward pushing of the Indian-Eurasia collision and local upper mantle material flow or significant anisotropies deep in the upper mantle.