前陆盆地逆冲断层类型与形成机制——以鄂尔多斯地块西缘和塔里木盆地北缘为例

具前陆盆地性质的鄂尔多斯地块西缘和塔里木盆地北缘发育九类逆冲断层:褶皱-逆冲断层型,褶皱-逆冲推覆型,高角度逆冲-牵引褶皱型,犁式逆冲-推覆型,同沉积基底逆冲断层型,基底楔冲断层型,基底背冲断层型,逆转逆冲断层型和基底平移-逆冲断层型。这些褶皱-逆冲构造的形成主要受板内地块或微板块间侧向挤压应力作用、基底缩短作用和滑脱作用的控制。

TYPES AND FORMATION MECHANISM OF THE THRUSTS IN FORELAND BASINS

The structure features of the fold-thrust belts in the western margin of Ordos Basin and the north margin of Tarim Basin can be classified into 11 types: 1. Fold-thrust type in the Gangder mountain and Kasangtouk anticlinal belts; 2. Fold-thrust and nappe type in the Xiaosong Mountains and north of Luntai area; 3. High angle thrust-drag fold type in the Hengshanbao and Kalpin region; 4. Listric thrust-nappe type in the Luo ShanMajiatan region; 5. Syndepositional basement thrust type in the Tiekesumiao and Sajinziarea; 6. Basement wedge thrust type in the Taolou and Xinhe region; 7. Basement back thrus type in the Luntai area; 8. Reversed thrust type, for example, Xilaifeng and north Wensu faults; 9. Basement wrench-thrust type, for example, Agia, Yingan and Zhenyiguan faults; 10. Basement wrench-fault type, for example, Kalayurgun fault;11. Surface wrench-fault type. The study area has the characteristics and evolution history of foreland basin. The fold-thrust structural be1ts in the basin have four kinds of formation mechanism: 1. Lateral compressive stress between the Ordos and Alashan terrains and between the Tarim and Junggar microplates; 2. Basement shorterning based on the prior-batheent detuchment; 3. Basement ramp with Luoshan-Majiatan listric thrusts as typification; 4. Surface decollement with Qiuritak anticlinal belt as typification.