摘要
合肥盆地的沉积作用与其东缘的郯庐断裂带演化有着良好的耦合关系。侏罗纪盆地发育主要受大别造山带演化控制,东部可见对同造山期郯庐断裂带左旋转换走滑的沉积响应。盆地内朱巷组的沉积是对早白垩世早期郯庐断裂再次发生陆内左行平移的响应,该时期成盆模式为一走滑—挠曲盆地。盆地内上白垩统—古近系的形成是对这期间郯庐断裂带伸展活动的响应,盆地具区域性伸展(双向伸展)的特征。盆地东部自新近纪以来的抬升、消亡与东缘反转构造的存在,指示了郯庐断裂带的逆冲活动。盆地东部的沉积记录结合近年来郯庐断裂带内部构造与同位素年代学的最新研究成果,指示该断裂带中-新生代经历了4个演化阶段:同造山期的左旋转换走滑、早白垩世早期的陆内左行平移、晚白垩世—古近纪的伸展运动和新近纪以来的逆冲活动。
Depositional characteristics of the Hefei Basin indicated a good coupling with evolution of the Tan-Lu fault zone to the east of the basin. The structural pattern of the pre-Jurassic basement and Jurassic sedimentation revealed that the basin developing was controlled by, in addition to the Dabie orogen, the syn-orogenic sinistral transform strike-slip movement of the TanLu fault zone. The Early Cretaceous Zhuxiang Formation showed the deposition being responses to intracontinental sinistral strike-slip movement of the fault zone, and a model of strike-slip flexure basin was proposed for development of the basin during this period. The Upper Cretaceous to Eogene sediments recorded an extensional activity along the Tan-Lu fault zone, during that time the basin was influenced by regional and intra-basinal extensions. The appearance of uplifting, closure and inversion structures on the eastern part of the basin during Neogene demonstrated that the thrusting occurred along the Tan-Lu fault zone. To synthesize the recent data of structural geology and isotopic datings from the fault zone, four evolutional stages of the Tan-Lu fault zone could be summarized, i.e. the synorogenic sinistral transform strike-slip movement in Jurassic, the early Early Cretaceous intracontinental left-lateral displacement, the extension from Late Cretaceous to Eogene and thrusting during Neogene.
出处
《地质科学》
CAS
CSCD
北大核心
2006年第2期256-269,共14页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
国家自然科学基金项目(批准号:49872074
40272094)。
关键词
合肥盆地
郯庐断裂带
沉积响应
构造演化
中-新生代
The Hefei Basin, The Tan-Lu fault zone, Sedimentary response, Tectonic evolution, Meso-Cenozoic
