四川攀西地区晚新生代构造变形历史与隆升过程初步研究  

Late Cenozoic tectonic deformation history and uplift process of the Panxi region,western Sichuan

作　　者：张岳桥[1] 杨农[1] 孟晖[2] 陈文[3] 

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]中国地质环境监测院,北京100081 [3]中国地质科学院地质研究所,北京100037

出　　处：《中国地质》2004年第1期23-33,共11页Geology in China

基　　金：国土资源部"十五"重点基础研究项目(20010202)资助。

摘　　要：基于TM遥感图像解译和野外调研，分析了攀西地区大渡河、安宁河深切河谷地貌特征和断裂带构造变形特征，建立了安宁河断裂带晚新生代5阶段变形历史。研究表明，中新世晚期—上新世早期，安宁河断裂以挤压走滑活动为主；上新世晚期至早更新世时期，断裂以斜张走滑活动为主，活动强度较弱；早中更新世之间发生的元谋运动使昔格达组湖相地层褶皱变形；中晚更新世时期发生断陷作用，形成安宁河两堑夹—垒的构造格局；晚更新世—全新世时期又以左旋走滑活动为主。综合安宁河、大渡河河谷地貌和晚新生代地层记录和变形特征，提出了攀西高原晚新生代4阶段隆升模式：中新世早中期(12Ma之前)以缓慢隆升与区域夷平化作用为主，中新世晚期—上新世早期(12～3．4Ma)是高原快速隆升与河流强烈下切的时期，上新世晚期—早更新世(3．4～1.1Ma)为昔格达湖盆发育时期，中晚更新世—全新世(1．1Ma以来)是高原快速隆升与河谷阶地发育时期。最后指出，至上新世晚期(3．4Ma以前)，攀西高原海拔高度可能超过了3000m。Based on TM image interpretation and field observations,this paper describes the geomorphological features of the deeply incised Daduhe and Anninghe River valleys in the Panxi region and analyses the late Cenozoic tectonic deformation features of the Anninghe fault zone.The late Cenozoic tectonic evolution of the Anninghe fault zone may be divided into5stages:late Miocene to early Pliocene,late Pliocene to early Pleistocene,early to middle Pleistocene,middle to late Pleistocene,and late Pleistocene to Holocene.The first stage mainly witnessed transpressional strike-slip faulting;in the second stage obliquely tensional strike-slip motion was dominant;the Yuanmou movement occurring in the third stage caused lacustrine strata of the Xigeda Formation to be folded;in the fourth stage normal faulting took place,forming the Anninghe graben-horst structure;in the fifth stage left-lateral strike-slip motion again predominated.Based on a morphostructural analysis of the deep incised valleys of the Daduhe and Anninghe Rivers,late Cenozoic stratigraphic records and deformation features,the authors propose a4-stage uplift model for the late Cenozoic uplift history of the Panxi plateau:a stage of gentle uplift and regional peneplanation during the early to middle Miocene(before12Ma),a stage of fast uplift and deep valley incision during the late Miocene to early Pliocene(from12to3.4Ma),a stage of development of the Xigeda lake basin along the deeply incised river valleys during the late Pliocene to early Pleistocene(from3.4to1.1Ma),and finally a stage of fast uplift and development of river terraces during the mid to late Pleistocene.The Panxi plateau may have attained an elevation of more than3000m above sea level by the late Pliocene(before3.4Ma).

关 键 词：构造变形 隆升 构造地貌 晚新生代 攀西地区 

分 类 号：P542.2[天文地球—构造地质学] P546[天文地球—地质学]