银川盆地新生代构造演化:来自银川盆地主边界断裂运动学的约束  

Cenozoic tectonic evolution of the Yinchuan Basin: Constraints from the deformation of its boundary faults

作　　者：黄兴富[1,2] 施炜[2] 李恒强[1,2] 陈龙[3,2] 岑敏[4,2] 

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国地质科学院地质力学研究所,北京100081 [3]中南大学地球科学与信息物理学院,湖南长沙410083 [4]合肥工业大学资源与环境工程学院,安徽合肥230009

出　　处：《地学前缘》2013年第4期199-210,共12页Earth Science Frontiers

基　　金：中国地质调查局项目(1212011120100;1212011120099)

摘　　要：银川盆地新生代以来主要沿其边界断裂发生多期断陷活动,其边界断裂运动学特征记录了盆地的形成演化历史。基于其边界断裂滑动矢量的详细测量与分析,结合区域构造、盆地内沉积序列以及叠加变形分析,提出银川盆地新生代主要受NW SE向伸展、NE SW向伸展与NE SW向挤压3期构造应力场控制。结合区域构造演化与相关年代学数据,银川盆地新生代以来主要经历初始断陷、持续断陷与拉分断陷等3期构造演化,始新世—上新世受NW SE向伸展作用控制,银川盆地两侧主边界断裂发生正倾滑活动,导致盆地发生强烈断陷活动,充填了始新世—上新世红色砂岩、砾岩;更新世期间,古构造应力场转变为NESW向伸展,其主边界断裂以左行斜张活动,银川盆地持续断陷沉降;晚更新世晚期(?)以来,在NE SW向挤压作用控制下,银川盆地主边界断裂发生强烈右行走滑兼正断活动,盆地受断裂剪切拉张活动,发生拉分断陷沉积。The Yinchuan Basin has undergone poly-phase subsidence along its boundary faults since the Cenozoic,and the kinematic characteristics of the boundary faults present the records of the Cenozoic evolution history of the Yinchuan Basin.On the basis of detailed measurement of the slip vector from the boundary faults of the Yinchuan Basin,together with regional structural analysis and superimposed deformation analysis,we propose that the Yinchuan Basin has been controlled by three-stage stress fields in the order of NW SE extension,NE SW extension and NE SW compression.Combined with the regional structural evolution,sedimentary sequences and geochronology,this paper suggests that the Yinchuan Basin has undergone a three-stage depression since the Cenozoic.Firstly,the NW SE extension resulted in intensive normally faulting and the occurrence of the Yinchuan Basin during the Eocene Miocene;secondly,the boundary faults are characterized by left strike-slip movement,and the Yinchuan Basin is marked by a successive depression due to the NE SW extension in the Pleistocene;lastly,the stress field transformed into the NE SW compression from NE SW extension since the Late Pleistocene,leading to the dextral movement of the boundary faults and an intensive trans-depression in the Yinchuan Basin.

关 键 词：银川盆地 贺兰山 新生代 构造演化 构造应力场 

分 类 号：P542.3[天文地球—构造地质学]