Crust Shortening of the Daliangshan Tectonic Zone in the Cenozoic Era and Its Implications  

作　　者：Chen Changyun He Honglin 

机构地区：[1]First Crust Monitoring and Application Center,CEA, Tianjin 300180, China [2]Institute of Geology, China Earthquake Administration, Beijing 100029, China

出　　处：《Earthquake Research in China》2009年第1期68-77,共10页中国地震研究（英文版）

基　　金：the National Natural Science Foundation of China(40472109);"973"State Key Basic Research Project of China(2004CB418410);Joint Eanthquake Science Foundation of China(105066)

摘　　要：The Daliangshan tectonic zone is a rhombic area to the east of the Anninghe and Zemuhe fault zones in the middle segment of the Xianshuihe-Xiaojiang fault system along the southeast margin of the Qinghai-Xizang （Tibet） Plateau. Since the Cenozoic era, the neotectonic deformation in the Daliangshan tectonic zone has presented not only sinistral slip and reverse faulting along the Daliangshan fault zone, but also proximate SN-trending crust shortening. It is estimated that the average crust shortening in the Daliangshan tectonic zone is 10.9 ± 1.6 km, with a shortening rate of 17.8 ± 2.2% using the method of balanced cross-sections. The crust shortening from folding occurred mainly in the Miocene and the Pliocene periods, lasting no more than 8.6 Ma. Based on this, a crust shortening velocity of 1.3 ± 0.2 mm/a can be estimated. Compared with the left offset along the Daliangshan fault zone, it is recognized that crust shortening by folding plays an important part in transferring crustal deformation southeastward along the Xianshulhe-Xiaojiang fault system.The Daliangshan tectonic zone is a rhombic area to the east of the Anninghe and Zemuhe fault zones in the middle segment of the Xianshuihe-Xiaojiang fault system along the southeast margin of the Qinghai-Xizang(Tibet)Plateau.Since the Cenozoic era,the neotectonic deformation in the Daliangshan tectonic zone has presented not only sinistral slip and reverse faulting along the Daliangshan fault zone,but also proximate SN-trending crust shortening.It is estimated that the average crust shortening in the Daliangshan tectonic zone is 10.9±1.6 km,with a shortening rate of 17.8±2.2% using the method of balanced cross-sections.The crust shortening from folding occurred mainly in the Miocene and the Pliocene periods,lasting no more than 8.6 Ma.Based on this,a crust shortening velocity of 1.3±0.2 mm/a can be estimated.Compared with the left offset along the Daliangshan fault zone,it is recognized that crust shortening by folding plays an important part in transferring crustal deformation southeastward along the Xianshuihe-Xiaojiang fault system.

关 键 词：Daliangshan tectonic zone Crust shortening Tectonic deformation Qinghai-Xizang （Tibet） Plateau 

分 类 号：P227[天文地球—大地测量学与测量工程] P618.130.2[天文地球—测绘科学与技术]