库车坳陷东秋里塔格断裂晚第四纪活动和滑动速率

Activity and Slip Rate of Dongqiulitag Fault in Kuqa Depression in Late Quaternary

摘要:

东秋里塔格断裂是库车坳陷内活动最为强烈的断裂之一,断错了波斯坦托克拉克河两岸的各级阶地。利用全站仪对河西岸的阶地变形进行了精确测量,得到Ⅰ、Ⅱ、Ⅲ级阶地形成以来东秋里塔格断裂的垂直断错量分别为12.5 m、20 m和24.5 m,并根据前人资料和区域类比的方法对各级阶地年龄进行了估计,计算得到晚第四纪以来该断裂的平均垂直滑动速率为1 mm/a左右,所引起的地壳缩短速率为(1.97~2.13)mm/a。

Abstract:

Dongqiulitag fault is one of the most active tectonics in Kuqa depression. The piedmont alluvial-pluvial fans and terraces of Bositantuoke-lake trivet are dislocated by the fault in different degrees. Through the field work, the biggest displacement along the fault on the terraces are measured with total station and differential GPS （Ashtech Promark2）, and the age of the terraces are estimated.. According to the fact that vertical displacements of the fault on the terrace Ⅰ-Ⅲ are 12.5 m, 20 m and 24.5 m, the average vertical slip rate of Dongqiulitage fault since late Quaternary is about 1 mm/a, and the relative average shortening rate is 1.97-2.13 mm/a.