文章摘要

文章信息/Info

Title:: Study on Late Quaternary Slip Rates of Two Faults within Jiuxi Basin

作者:: 刘兴旺¹; 2; 袁道阳¹; 苏琦³; 吴赵¹; 柳煜¹; (1.中国地震局兰州地震研究所,甘肃兰州 730000; 2.兰州地球物理国家野外科学观测研究站,甘肃兰州 730000; 3.南京大学地球科学与工程学院,江苏南京 210046)

Author(s):: LIU Xingwang¹; 2; YUAN Daoyang¹; SU Qi³; WU Zhao¹; LIU Yu¹; (1. Lanzhou Institute of Seismology,China Earthquake Administration,Lanzhou 730000,Gansu,China)(2. Lanzhou National Observatory of Geophysics,Lanzhou 730000,Gansu,China)(3. School of Earth Science and Engineering,Nanjing University,Nanjing 210046,Jiangsu,China)

摘要:: 通过卫星影像解译、差分GPS测量和地貌年代学样品采集,对位于酒西盆地内部的阴洼山断裂和新民堡断裂晚第四纪滑动速率进行了研究。阴洼山断裂发育于阴洼山东侧,总体走向315°,长约25 km; 新民堡断裂整体走向300°,长约20 km,二者皆为全新世活动的逆断层。通过野外考察,选择典型断错地貌进行断层陡坎测量,结合所获相应地貌面的年代数据,得到阴洼山断裂和新民堡断裂晚第四纪垂直滑动速率分别为(0.08±0.02)mm/a和(0.11±0.02)mm/a。结合断裂倾角及前人研究资料,得到垂直祁连山方向酒西盆地内部断裂的地壳缩短速率约为1 mm/a,整个盆地地壳缩短速率约为2.4 mm/a。

Abstract:: Based on satellite image interpretation,differential GPS measurement and geomorphologic chronology sampling,we carried out a detail study on the Late Quaternary slip rates of the Yinwashan and Xinminpu faults located in the Jiuxi basin. The Yinwashan fault is located at the eastern side of the Yinwashan with an overall strike of 315° and a length of about 25 km. The Xinminpu fault strikes 300° with a length of 20 km. Both of the two faults are Holocene active reverse faults. Through the detailed field investigation,we measured the fault scarps at the typical fault landform site. Combining the chronological date of the corresponding surface,we got the vertical slip rates for the tow faults in the Late Quaternary are(0.08±0.02)mm/a and(0.11±0.02)mm/a,respectively. Combined with the fault dip and previous research data,it is found that the crustal shortening rate of the internal faults in the Jiuxi basin is about 1 mm/a,and the shortening rate of the crust in the Jiuxi basin is about 2.4 mm/a.