扬子北缘镇巴-高川地区两类不同二叠系对比及区域构造意义  

Stratigraphic Correlations of Two Different Types of Permian Strata and Their Regional Tectonic Significance in Zhenba-Gaochuan Area,Northern Margin of Yangtze Block

作　　者：李瑞保[1,2] 裴先治[1,2] 刘战庆[2] 李佐臣[1,2] 丁仨平 陈有 刘智刚[2] 张晓飞[2] 陈国超[2] 

机构地区：[1]长安大学西部矿产资源与地质工程教育部重点实验室,陕西西安710054 [2]长安大学地球科学与资源学院,陕西西安710054

出　　处：《地球科学与环境学报》2011年第2期125-131,共7页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(40972136;40572121);中央高校基本科研业务费专项项目(CHD2009JC070;CHD2009JC053;CHD2009JC046);中国石油化工股份有限公司海相前瞻性研究项目(YPH08006)

摘　　要：通过1∶50 000陕西镇巴—高川地区区域地质调查,发现镇巴地区和高川地区二叠系具有完全不同的岩石组合特征及生物化石,前者主要为一套稳定的碳酸盐岩相沉积,后者主要为一套较深水相黑色岩系沉积。经对典型地区实测剖面、古生物及岩石组合特征详细对比研究,发现二者虽然时代相同,但是不能横向对比,应为同期异相的产物。在综合区域地质资料基础上,探讨上述二叠系所表征的区域构造意义。两套二叠系岩相的差异性说明镇巴地区和高川地区当时曾分处在不同的沉积-构造环境:镇巴周缘以米仓山和星子山地层小区为代表的物质建造与扬子地块整体升降和海水的频繁进退密切相关,而高川周缘以褚河地层小区为代表的物质建造则更可能与早期地壳隆升、晚期地壳张裂成盆和海水贯入有关。综合区域地质资料研究认为,高川地区地层系统与勉略带地层系统相似,表明其早期与勉略带有着大致相同的构造演化史,也表明高川盆地曾经是晚古生代勉略裂谷—有限洋的一部分,只是被后期构造改造而残存于现今高川一隅。Through 1∶50 000 regional geological survey in Zhenba-Gaochuan Area,there were two distinctly types of Permian strata with different rock association and fossils.Permian strata in Zhenba Area mainly consisted of the stable carbonate deposit,Permian strata in Gaochuan Area consisted of black rock series of deeper water facies.Comparing with measured section,fossil and rock association in typical area,the above Permian strata were contemporaneous and heteropic.Based on the regional data,the regional tectonic significances of the Permian strata were discussed.The difference of lithofacies characteristic of the Permian strata indicated that Zhenba and Gaochuan Areas located in absolutely different sedimentary-tectonic environment.The sediment constructions in Zhenba Area characterized as the Micangshan and Xingzishan stratigraphic microprovinces were closely related to the lifting and lowering of Yangze Block and continually marine transgression and regression;the sedimentary constructions in Gaochuan Area characterised as the Chuhe stratigraphic microprovince were possibly related to the crust uplift in Early Paleozoic,crust crack in Late Paleozoic and marine pouring.In general,the similarity of the stratigraphic systems in Gaochuan Area and Mianlue tectonic belt showed that the two stratigraphic systems had the similar tectonic evolution history;the Gaochuan Basin was ever a part of the Neopaleozoic Mianlue rift-limited ocean,and it was replaced to the Gaochuan Area by the late tectonic movement.

关 键 词：扬子北缘 二叠系 黑色岩系 区域构造 晚古生代 镇巴—高川地区 

分 类 号：P534.46[天文地球—古生物学与地层学]