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秀沟盆地是发育在东昆仑走滑断裂带上的一级拉分盆地,位于该断裂带西大滩-东大滩段与托索湖段的左阶连接部位。本研究通过解译分析高分辨率遥感影像和数字高程模型(DEM)数据,并结合野外高精度实时差分GPS(RTK-GPS)测量数据,对秀沟盆地第四纪构造活动及其地貌特征进行了研究。研究结果表明,沿东昆仑活动断裂带秀沟盆地段发育了晚第四纪地表地震破裂带、次级走滑拉分盆地、错断阶地陡坎、错断冲积扇等典型走滑构造地貌特征。其中秀沟盆地东北部发现约50km长,而且保存完好的地表地震破裂带,很可能是1902年秀沟盆地东北部M7.0级的地震地表破裂带。在破裂带的长度上,它与1963年发生在其东部阿拉克湖段的M7.0所产生的40km长的地震地表破裂带相近。高分辨率遥感影像的解译结果表明,冲积扇上发育的河流T3阶地与T4阶地之间发生了90m左右的水平断错累积位移,根据同一海拔高度沉积物的宇宙成因核素暴露年代测定资料得出的T3和T4阶地的形成年龄分别是6276±262a和8126±346a,估算出东昆仑活动断裂带秀沟盆地段全新世以来的平均走滑速率为12.9±2.9mm/a。此外,遥感影像解析和野外测量指示晚第四纪冲积扇发生的累积错断距离为2970±30m,根据这些推测冲积扇形成年代约为297±19kaB.P.,由此估算出秀沟盆地段晚更新世以来的长期平均走滑速率为10.1±0.8mm/a。两者结果接近,表明东昆仑活动断裂带秀沟盆地段晚第四纪以来有比较一致的走滑速率。
The Xiuugou Basin is a first-class pull-apart basin developed on the strike-slip fault zone of the East Kunlun and is located at the left-hand connecting part of the Xidatan-Dongdaitan and Torsodurian sections of the fault. In this study, the interpretation and analysis of high-resolution remote sensing images and digital elevation model (DEM) data, combined with the field of high-precision real-time differential GPS (RTK-GPS) measurement data, Quaternary tectonic activities in Xiu groove and its features Study. The results show that typical strike-slip tectonic features such as Late Quaternary seismic rupture zone, secondary strike-slip subbasin, fault terrace, fault fault alluvial fan, etc. are developed in the Xiu-ditch basin along the active fault zone in the East Kunlun Mountains . Among them, a surface rupture zone of about 50 km long and well-preserved in the northeast of the Xiugerou Basin is likely to be an M7.0 earthquake surface rupture zone in the northeast of the Xiu-ditch basin in 1902. On the length of the rupture zone, it is similar to the 40 km long earthquake surface rupture zone produced by M7.0 in its eastern Arak Lake segment in 1963. Interpretation results of high resolution remote sensing images show that there is a cumulative horizontal displacement of about 90 m between T3 and T4 terraces of alluvial fan. Based on the dating data of cosmic nuclide exposure at the same altitude, The formation ages of T3 and T4 terraces are 6276 ± 262a and 8126 ± 346a, respectively. The average slip rate since the Holocene was estimated to be 12.9 ± 2.9mm / a in the eastern Kunlun active fault zone. In addition, the accumulated fault dislocation distance of late Quaternary alluvial fan indicated by remote sensing image analysis and field measurement was 2970 ± 30m. Based on these speculations, the age of alluvial fan formation was about 297 ± 19kaB.P., The long-term average strike-slip rate since the late Pleistocene was 10.1 ± 0.8 mm / a. The results are similar, indicating that there is a consistent strike-slip rate since the Late Quaternary in the eastern Kunlun Mountains active fault zone.