郯庐断裂带泗洪段晚中生代以来地层特征及其沉积-构造响应--以SHJ02钻孔为例  

Sedimentary characteristics and sedimentary-tectonic responses of the Sihong segment of Tan-Lu fault zone since the Late Mesozoinc:A case study of borehole SHJ02

作　　者：蒋仁[1] 曾剑威[1] 刘凯[1] 李长波 周效华[1] 赵玲[1] 于俊杰[1] 彭博[1] 劳金秀[1] JIANG Ren;ZENG Jian-wei;LIU Kai;LI Chang-bo;ZHOU Xiao-hua;ZHAO Ling;YU Jun-jie;PENG Bo;LAO Jin-xiu(Nanjing Center,China Geological Survey,Nanjing 210016,China)

机构地区：[1]中国地质调查局南京地质调查中心,南京210016

出　　处：《华东地质》2020年第2期97-107,共11页East China Geology

基　　金：中国地质调查局“长江三角洲沪宁杭地区区域地质调查(编号:DD20190043)”;“长三角覆盖区1∶5万填图试点(编号:DD20160063)”项目联合资助。

摘　　要：江苏泗洪及周边地区晚中生代以来的沉积盆地演化及现今地形地貌的形成,主要受控于郯庐断裂带泗洪段多期构造活动。新近纪—第四纪松散沉积物完整记录了新构造运动控制下的沉积基底起伏特征和沉积物堆积过程。文章以泗洪段SHJ02钻孔为例,在钻孔岩心特征分析及地层序列划分的基础上,探讨了该区古地理环境及构造演化特征。SHJ02钻孔孔深246.00 m,自上而下揭示的地层包括:第四系(埋深0~47.43 m)、新近系(埋深47.43~239.52 m)、晚白垩世红层(埋深239.52~242.70 m)及早白垩世火山岩(埋深>242.70 m)。该区晚中生代—新生代地层序列和沉积格架特征,揭示了郯庐断裂带泗洪段晚白垩世断陷沉积、古近纪隆升剥蚀、新近纪伸展环境下河-湖相沉积,以及第四纪晚期挤压背景下快速隆升的构造演化过程。新近纪—第四纪河道演化变迁、河-湖相频繁交替等沉积体系的快速转换是对郯庐断裂带泗洪段新构造运动的响应。The evolution of sedimentary basin since the Late Mesozoic in Sihong and surrounding areas of Jiangsu Province and the formation of present landform are mainly controlled by the multi-stage tectonic activities in the Sihong segment of Tan-Lu fault zone.The fluctuation characteristics of sedimentary basement and deposit accumulation process under the control of neotectonic movement are completely recorded by the Neogene-Quaternary loose sediments.Taking the borehole SHJ02 in Sihong segment for example,the paleogeographic environment and tectonic evolution characteristics are discussed based on the analysis of borehole core features and stratigraphic sequence division.The depth of borehole SHJ02 is 246.00 m,revealed strata including the Quaternary(buried depth of 0~47.43 m),Neogene(47.43~239.52 m),Late Cretaceous red bed(239.52~242.70 m)and Early Cretaceous volcanic rock(more than 242.70 m)from top to bottom.The characteristics of Late Mesozoic-Cenozoic stratigraphic sequences and sedimentary framework show the tectonic evolution processes as the deposition of Late Cretaceous fault depression,Paleogene uplift and denudation,fluvial-lacustrine sediments in the Neogene extensional environment,and rapid uplift under the background of late Quaternary compression in the Sihong segment of Tan-Lu fault belt.The rapid transformation of sedimentary systems such as the Neogene-Quaternary channel evolution and frequent alternations of fluvial-lacustrine facies is a response to the neotectonic movement in the area.

关 键 词：新近系 第四系 地层序列 新构造运动 郯庐断裂带泗洪段 江苏 

分 类 号：P546[天文地球—构造地质学] P532[天文地球—地质学]