沉积学报2017，Vol.35Issue(2)：299-314,16.DOI:10.14027/j.cnki.cjxb.2017.02.009
西湖凹陷渐新世层序地层格架与沉积充填响应
Oligocene Sequence Framework and Depositional Response in the Xihu Depression, East China Sea Shelf Basin
摘要
Abstract
The East China Sea Shelf Basin (ECSSB) is the largest sedimentary basin in offshore China,which contains the largest hydrocarbon bearing unit of Xihu Depression.However,after years of exploration practices,the Huagang Formation in Oligocene has been proven as a major gas reservoir,which has undergone controversy on subdivision of sequence stratigraphy and types of sedimentary systems for a long time.Combining with basin structure and tectonic context,this study subdivides the Oligocene into 5 third-order sequences and 12 system tracts in the Xihu Sag on the basis of base level cycle analysis,core calibration,and seismic reflection features.Furthermore,sedimentary environments were identified by core description,sedimentary structures,trace fossils,and geochemical analysis.Typical sedimentary sequences were established including fluvial,delta,tidal estuary,and beach-bar systems.Sedimentary system types and distribution have been clarified of the Huagang Formation in the Xihu Sag.In the Oligocene,the Xihu Sag was in a transitional environment (mainly in lacustrine environment),which experienced two major times of marine transgressions (around 29.5 Ma and 24.3 Ma).Depositional systems were diverse from south to north,mainly consisting of deltas in the short axis from east to west,tidal estuaries in the south,and beach-bars in the northeast gentle slope.Finally,tectonic-sedimentary genetic model has been established in the ECSSB,showing basin tectonic setting and depositional response under the context of rifting-depression transition and marine-continental alternation.关键词
西湖凹陷/花港组/层序划分/沉积响应Key words
Xihu Sag/Huagang Formation/sequence subdivision/depositional response分类
天文与地球科学引用本文复制引用
于兴河,李顺利,曹冰,侯国伟,王亚风,皇甫志远..西湖凹陷渐新世层序地层格架与沉积充填响应[J].沉积学报,2017,35(2):299-314,16.基金项目
国家科技重大专项项目(2011ZX05023-001-009) （2011ZX05023-001-009）
中国博士后科学基金项目(2015M581269) （2015M581269）
国家自然科学基金项目(41572080)[National Science and Technology Major Project,No.2011ZX05023-001-009 （41572080）
China Postdoctoral Science Foundation,No.2015M581269 （）
National Natural Science Foundation of China,No.41572080)] （）
