西昆仑山前乌泊尔逆冲推覆带构造特征

乌泊尔逆冲推覆带自南向北可划分出3排构造,分别为西南部的西昆仑逆冲推覆体、东北部的乌泊尔弧形逆冲推覆断裂以及夹于它们之间的乌泊尔盆地。对野外露头与地震剖面的综合分析表明,乌泊尔逆冲推覆断裂沿古近系底部的膏泥岩层滑移,并向上逆冲推覆至地表,近地表处的强反射不整合波组对应的地层为下更新统下部;乌泊尔逆冲推覆构造始于晚上新世,且一直持续活动至今。乌泊尔逆冲推覆断裂呈东、西两端抬升、中部下凹的鞍状形态。断裂东段为侧断坡,构造具走滑特征;西段呈强显露型逆冲至地表。

Structural characteristics of Wuboer thrust belts in the foreland of West Kunlun Mountain

The Wuboer thrust belt consists of three rows of thrusts from south to north, including the West Kunlun thrust body in the southwest part, the arc Wuboer Fault in the northeast part, and the Wuboer Basin between above two parts. The field observation and structural analysis of seismic section show that the Wuboer Fault slides along the anhydrite mudstone layer located at the bottom of Eogene and thrusts up to ground surface. The bright unconformity reflection wave near the surface responds to the bottom of the Lower Pleistocene. The Wuboer thrust construction started at the Late Pliocene and is active at present. The east and west lips of Wuboer Fault are higher than middle part of that. The fault is shaped with saddle. The east fragment of structure is side ramp and characterized by strike slip. The west fragment of structure thrusts up to ground surface.