海洋地质前沿2025，Vol.41Issue(8)：71-82,12.DOI:10.16028/j.1009-2722.2024.210
东海陆架盆地丽水凹陷古新统泥岩岩相划分及其油气地质意义
Lithofacies classification and its hydrocarbon geological significance of the Paleogene mudstones in the Lishui Sag,East China Sea Shelf Basin
摘要
Abstract
Through the analysis of thin section,X-ray diffraction(XRD)and Rock-Eval pyrolysis,the Paleocene mudstones in the Lishui Sag of the East China Sea Shelf Basin were classified into different lithofacies,and the organic matter(OM)content and hydrocarbon generation potential were compared.Results show that the lithofa-cies of the Paleocene mudstones in the Lishui Sag can be divided into laminar mudstones,sandy-massive mud-stones,and muddy-massive mudstones based on their sedimentary structure and XRD mineral composition.In the laminar mudstone,the mineral matrix lamina and organic lamina are interlayered and discontinuously distributed,the OM content and hydrocarbon potential are the greatest among all the lithofacies,and such a mudstone is dis-tributed in the western Sub-sag mainly and mostly developed in the Yueguifeng Formation.The sandy-massive mudstone has a high content of felsic minerals(feldspar and quartz)with large particle size;the muddy-massive mudstone has a high content of clay minerals and are distributed evenly;and the OM in both lithofacies is scattered in the mineral matrix in the form of organic particles,with low OM content and hydrocarbon potential.The sandy-massive mudstone is mainly developed in the Lingfeng and Mingyuefeng formations in the whole sag,while the muddy-massive mudstone is mainly developed in the Yueguifeng Formation in the eastern sub-sag.Fur-thermore,by comparing the OM content and hydrocarbon potential of the Paleocene source rocks in the Lishui Sag with the main source rocks that developed in the Paleocene land area and post-Eocene marine area in China's offshore with petroleum discoveries,it is found that the Paleocene source rocks in the Lishui Sag have relatively higher OM content and hydrocarbon potential,which deserves to be continuously explored for oil and gas.Over-all,the characteristics of OM content,hydrocarbon potential,and their spatiotemporal distribution of mudstones with different lithofacies vary greatly in the Lishui Sag of the East China Sea Shelf Basin,and the in-depth under-standing of source rocks in this region should focus on the laminar mudstone and the Yueguifeng Formation of the western sub-sag,which is of great significance in guiding its exploration and development of hydrocarbons.关键词
岩相/有机质/生烃潜力/古新统/丽水凹陷/东海陆架盆地Key words
lithofacies/organic matter/hydrocarbon generation potential/Paleogene/Lishui Sag/East China Sea Shelf Basin分类
海洋科学引用本文复制引用
陈刚,朱晓军,蒋一鸣,朱伟林..东海陆架盆地丽水凹陷古新统泥岩岩相划分及其油气地质意义[J].海洋地质前沿,2025,41(8):71-82,12.基金项目
国家自然科学基金重点项目"中—新生代东海含油气盆地差异演变及控制机制"(42430806) （42430806）
上海市自然科学基金"东海盆地丽水凹陷古新统烃源岩有机质赋存及生烃特征研究"(21ZR1468900) （21ZR1468900）
