冰后期胶州湾层序地层划分与沉积环境演变  

CLASSIFICATION OF SEQUENCE STRATIGRAPHY AND EVOLUTION OF DEPOSITIONAL ENVIRONMENT FOR JIAOZHOU BAY SINCE POST-GLACIAL

作　　者：董贺平[1,2] 李广雪[1] 李绍全[2] 李春[2] 

机构地区：[1]中国海洋大学海洋地球科学学院,青岛266100 [2]国土资源部海洋油气资源与环境地质重点实验室,青岛266071

出　　处：《海洋地质与第四纪地质》2008年第6期1-7,共7页Marine Geology & Quaternary Geology

基　　金：国家重点基础发展研究规划项目(2005CB422304);青岛市地质环境质量评价和生态与经济可持续发展项目([2003]20-04)

摘　　要：通过对胶州湾青岛近海沉积物微古化石及浅层地震资料的综合解释,运用层序地层概念,确定了层序界面的划分方法。初次海泛面之下为河流沉积,微体古生物缺乏,其上岩性以含贝壳的砂质粗粒为主,微古特征表现为低丰度、低分异度。浓缩段岩性为虫孔发育的泥质细粒组分,微古丰度出现最高值。据此可将胶州湾青岛近海层序地层划分为半个三级层序,海进体系域发育海侵边界层、潮沟充填及古滨岸沉积,高位体系域形成大沽河洋河复合三角洲沉积体及湾口两侧的潮汐三角洲沉积体。以层序的方法研究近岸沉积物有利于不同地域不同时代地层间的对比,通过岩性和微体化石及矿物分布等特征综合确定海泛面,在具有多物源、快速沉积特点的近岸海湾有一定的现实意义。Definition of sequence stratigraphy on the offshore of Qingdao is carried out based on the analysis of microfossil properties of QDD3 core sediments and seismic data. Depositional system research is helpful to the spatial and space stratigraphy comparison using the conception of sequence. A half third-level se- quence, considering no obvious evidence of sea-level drop in the East China Sea region, can be classified, which is composed of Transgressive Systems Tract （TST） and Highstand Systems Tract （HST） on the study area. Transgression boundary formation is an important interface above riverbed sediment. Its li- thology is sandy coarse sediments and abundant with shell fragments. Microfossil abundance and diversity is at low-level. Lithology in condensed section is mainly mudy fine particle with worm holes, and abun- dance of microfossil gets its maximum value. Distinguishing of marine flooding surface from condensed sec- tion in the offshore region by seismic reflection feature is sometimes difficult as for the rapid depositional rate and multi-resources, so integrated utilization of lithology, microfossil and mineral character can be an effective method for recognizing the sequence stratigraphy.

关 键 词：层序地层 界面划分 沉积演化 冰后期 胶州湾 

分 类 号：P736.2[天文地球—海洋地质]