塔木素预选区第四纪构造活动性的光释光测年分析

内蒙古塔木素地区地处中蒙边境,位于阿拉善右旗,是高放废物粘土岩处置库的预选场址。预选区内大部分地区被第四系地层覆盖,发育多条断裂构造,断裂构造第四纪以来的活动性对于预选区有利地段的最终确定具有重要的科学和现实意义。本文以塔木素地区北部靠近控盆断裂的塔木素断裂为研究对象,利用光释光定年技术研究该断裂晚第四纪的活动性。通过野外地质调查和高分辨率卫星遥感影像发现塔木素断裂东段错段一条干枯的河流,我们对河流阶地采集光释光样品,测得光释光年龄为56.8±5.2ka,结合河流阶地的高程曲线可以看出塔木素断裂晚第四纪以来活动性弱。

Optically stimulated luminescence dating analysis of Quaternary tectonic activity in the pre-selected area of Tamusu

Tamusu area in Inner Mongolia is located on the border between China and Mongolia, in Alxa Youqi, is the pre-selected site for clay rock repository of high-level radioactive waste. Most of the preferred area is covered by Quaternary strata, and there are many near-east-west faults. The activity of fault structures since Quaternary has important scientific and practical significance for the final determination of favorable areas in the preferred area. In this paper, the Tamusu fault near the basin-controlling fault in the north of Tamusu area is taken as the research object, and the activity of the fault in Late Quaternary is studied by using the optically stimulated luminescence dating dating technique. Through field geological survey and high resolution satellite remote sensing images, we found a dry river in the eastern staggered section of the Tamusu fault. We collected optically stimulated luminescence samples from river terraces and measured the optically stimulated luminescence age of 56.8+5.2ka. Combining with the elevation curve of river terraces, we can see that the activity of the Tarim fault has been weak since late Quaternary.