渤海湾西MIS3阶段海侵边界探讨  

Discussion on the transgression boundary of MIS3 stage in the western coast of Bohai Bay

作　　者：鲁庆伟[1] LU Qingwei(Geological Institute of North China Geological Exploration Bureau of Tianjin, Tianjin 300170, China)

机构地区：[1]天津华北地质勘查局地质研究所,天津300170

出　　处：《中国地质调查》2021年第1期89-96,共8页Geological Survey of China

基　　金：中国地质调查局天津地质调查中心“天津1∶5万静海、唐官屯幅区域地质调查(编号:津[2016]01040-14)”;天津市规划和自然资源局“天津市蔡公庄乡幅、南台幅、中旺镇幅和太平镇幅1∶5万区域地质调查(编号:国土房任[2014]20号)”项目联合资助。

摘　　要：渤海湾西天津南部平原区是研究海侵和海平面变化的天然理想场所。基于2个钻孔(ZKQ1孔和ZK1孔)沉积特征、测年(AMS 14C)及微体古生物和生物壳体等综合研究,推测研究区MIS3阶段第2海侵的最大影响边界在ZK1孔和ZKQ1孔两孔之间,界线西侧表现为河湖相的陆相沉积,界线东侧为滨海湖沼的过渡相沉积,该位置即是现今黑龙港河一带,也曾是古河道故道,推测该期海侵影响范围受到了古河道制约。结合研究区前期3个钻孔(ZKQ4孔、CGZ5孔和CGZ7孔)资料,建立了E→W向(海→陆)联合钻孔对比剖面,进一步对MIS3阶段海侵层位追踪,表明E→W依次由海相(CGZ7孔、CGZ5孔)→过渡相(ZKQ4孔、ZKQ1孔)→陆相(ZK1孔)相变。推测研究区内MIS3阶段海侵边界位于静海区的东尚码头村(CGZ5孔)和高家庄(ZKQ4孔)一带。研究成果对恢复该区域古地理演化、海平面变迁研究以及水工环地质勘查等具有重要意义。The Southern Tianjin Plain,located in the western coast of Bohai Bay,is an ideal natural place to study the transgression and sea level change.Based on the comprehensive research of sedimentary characteristics,dating(AMS 14C)and micro paleontology of two boreholes(ZKQ1 and ZK1),the authors inferred that transgression maximum influence boundary in the MIS 3 stage was between two boreholes(ZK1 and ZKQ1).The western side of the boundary is continental sedimentary,and the eastern side of the boundary is transitional sedimentary.boundry location was in the area of the present Heilonggang River and was once an ancient river channel,so it is speculated that the area affected by the transgression in this period was restricted by the ancient river channel.Combined with the previous three boreholes(ZKQ4,CGZ5 and CGZ7)data,the author has established the profile of the E→W direction(sea→land)and further confirmed that E→W in this area was transformed from Marine facies(CGZ7 and CGZ5)to transitional sedimentary(ZKQ4 and ZKQ1)to continental facies(ZK1).It is speculated that the transgression boundary of MIS3 is in the area of Dongshangmatou(CGZ5)and Gaojiazhuang(ZKQ4)in Jinghai district.This achievement is of great significance to the restoration of paleogeographic evolution,the sea-level change research and the geological exploration of hydraulic environment in this region.

关 键 词：渤海湾 海侵 测年 MIS3阶段 沉积环境 

分 类 号：P534.63[天文地球—第四纪地质学]