塔西南坳陷北缘新生代构造形变特征

CHARACTERISTICS OF CENOZOIC STRUCTURAL DEFORMATION IN NORTH MARGIN OF SOUTHWEST DEPRESSION, TARIM

塔西南坳陷北缘的新生代构造形变受控于近南北向的挤压。由于所处构造位置不同，西段和东段变形样式有很大差别。据此，可划分成东西两个变形区：西部称南天山前缘构造变形区；东部称麦盖提斜坡北缘构造变形区。前者构造形变与南天山冲断一褶皱带向南的推挤密切相关，并受西昆仑冲断－褶皱带向北推挤的叠加改造。总体呈自南而北的前展式，变形样式主要有：叠瓦状断裂组合、断弯背斜、构造三角带、隔挡式褶皱等。后者的西段受色力布亚断裂控制，以边冲与走滑复合为主要变形机制，形成沿断裂走向分布的断裂背斜带；东段受玛扎塔格断裂控制，以左旋压担为主要变形机制，形成复杂的扭动断裂带。

The structural deformation during Cenozoic along north margin of southwest-depressionin Tarim Basin is controlled by about S-N direction compressive stress field. It can be dividedinto two segments in terms of the deformational styles. The west segment is called frontalsouth Tianshan Moutains structural deformation region which is related to the southwardpush-compression of south Tianshan Mountains thrust -fold belt. and the .superimposion ofwest Kunlun mountains fault-fold belt. Its deformational styles include: lubricate fault assemblage, fault-bent anticlille, structural delta belt and baffle fold. The east one is callednorth Maigaiti slope structural deformation region which is controlled by Selibuya fault andMazatage fault. Its deformation styles include a fault--anticline belt along the main fault and acomplex wrench fault belt.