北黄海盆地东部坳陷北部物源-沉积体系

Provenance-sedimentary system in the northern part of eastern depression in North Yellow Sea Basin

为探讨北黄海盆地东部坳陷北部物源-沉积体系的基本特征,笔者采用岩心样品的镜下鉴定和地震反射特征分析相结合的方法对东部坳陷的岩性岩相进行研究。结果表明:东部坳陷内存在由北向坳陷中心进积的砂体,沉积区以碎屑岩沉积为主,岩石中物质成分以花岗质和碳酸盐岩含量高为特征,沉积物来源于盆缘隆起的风化剥蚀及前中生界基底;北部沉积体系从中侏罗世—晚侏罗世—早白垩世均以扇三角洲沉积体系为主,不同时期发育规模有所差别。综合分析认为,北部为风化物源,(扇)三角洲-水下扇沉积体系。

To explore the basic characteristics of the provenance-sedimentary system in the northern part of the eastern depression of the North Yellow Sea Basin,the authors conducted a study of the lithology and facies of the eastern depression using a combination of microscopic identification of core samples and seismic reflection feature analysis.The results indicate that there are sand bodies deposited from the north towards the center of the depression,with clastic rock sedimentation predominating in the area.The rock composition is characterized by high contents of granitic and carbonate materials,with sediment coming from weathering and erosion of the basin s peripheral uplift and the Pre-Mesozoic basement.The northern sedimentary system is primarily a fan delta sedimentary system during the Middle to Late Jurassic and Early Cretaceous,with varying scales of development during different periods.A comprehensive analysis suggests that the north is a weathered provenance,characterized by a(fan)delta-subsubaqueous fan sedimentary system.