摘要
阿尔金断裂是由阿尔金主干断层及其他次级断裂面组成的巨型走滑断裂系 ,其分布规律符合左行走滑挤压模式。昌马盆地位于阿尔金断裂带东段 ,它的古应力场与阿尔金断层的运动方向一致。昌马盆地北界是阿尔金主干断层 ;南界由锯齿状相交的半截子井—野马山断层、野马山断层、石板墩—龚岔口断层、中祁连北缘断层组成 ,分别是阿尔金主干断层的S面、小型Y面、P面、S面 ;东界由香毛山西断层、马舌头断层、青石岩断层组成 ,分别是阿尔金主干断层的X面、S面、R’面 ,昌马盆地是由这些断层围限的狭长三角形。因此 ,昌马盆地是阿尔金断裂带中主干断层与分枝断层联合作用形成的走滑分枝盆地。盆地经历了侏罗纪—白垩纪的拉张作用 ,接受了巨厚的沉积 ;晚第三纪到第四纪由于阿尔金断裂左行走滑运动 ,盆地反转 ,处于受挤压状态 ,形成走滑分枝盆地。通过对昌马盆地石油地质特征的分析 ,认为昌马盆地具有形成油气的有利地质条件 ,应加强勘探力度。
The Altyn fault is a major strike slip fault system that consists of the main fault and the second order faults with a distribution pattern corresponds to the left lateral strike slip transpression model. The Changma basin is located to the south flank of the eastern segment of the Altyn fault zone, whose paleo stress field is in accordance with kinematic direction of the Altyn fault. The northern border fault of the Changma basin is the east segment of the Altyn main fault. The south border makes up the zigzag Banjiezijing Yemashan fault, the Yemashan mountain fault, the Shibandun Gongchakou fault, and the north border fault of the central Qilian mountain, which are S fracture, small Y fracture, P shear, and S second order fracture of the Altyn fault respectively. The eastern border is composed of the west Xiangmaoshan fault, the Mashetou fault, and the Qingshiyan fault, which are X fracture, S fracture, and R' shear of the Altyn fault respectively. The Changma basin is a narrow triangle in map view surrounded by those fauls. Therefore, we conclude that the Changma basin is a strike slip branch basin formed by interaction of the Altyn main fault and its branch faults. During the Jurassic Cretaceous, the Changma area was tensioned and buried by thick deposits. From the later Tertiary to Quaternery, the Changma strike slip branch basin inversed and was pressed horizontally caused by the emplacement of the sinistral strke slip Altyn fault. Having analyzed the petroleum geological features of the Changma basin, the authors emphasize that there are advantageous conditions of hydrocarbon genesis in the Changma basin, and more attention and investment should be devoted to the exploration in this area.
出处
《高校地质学报》
CAS
CSCD
2001年第1期13-20,共8页
Geological Journal of China Universities
基金
国家自然科学基金! (No .49832 0 40 )资助
