天山北麓活动构造基本特征

在近ＳＮ向强烈挤压下，天山北麓发育了两个不同类型的大型逆冲推覆构造，一是乌鲁木齐以西具有典型断裂扩展褶皱特征的依连哈比尔尕山山前推覆构造，二是乌鲁木齐以东博格达山前弧形推覆构造；同时水平剪切作用成了大型斜切天山的右旋走滑断裂。ＮＷ－ＮＮＷ向的博罗科努一阿齐克库都克断裂切割天山，右旋走滑特征非常清楚。天山北麓的应变分配特征在内陆造山带中具有典型性。

BASIC FEATURES OF ACTIVE STRUCTURES AT THE NORTHERN FOOTHILL OF TIANSHAN MOUNTAINS,CHINA

Two types of large-scale thrust-nappe systems were developed at the northern foot of Tianshan mountains in respond to intensive under the strong N-S compression. One is Erenharbirga piedmont nappe structure west of Urumqi with the typical features of fault propagating fold system. The other is Bogda piedmont arched nappe structure east of Urumqi. Meanwhile horizontal shearing led to formation of large-scale right-lateral strike-slip fault obliquely cutting through the Tianshan mountains. Bonokno-Aqikkuduk fault trending NW-NNW is a typcial right-lateral fault system. The strain distribution pattern at the northern foot of the Tianshan mountains is typical for inland orogenies.