北黄海盆地东部坳陷中生界沉积特征及演化  

Sedimentary Characteristics and Evolution of Mesozoic in the Eastern Depression,North Yellow Sea Basin

作　　者：王改云[1] 刘金萍[1] 王后金[1] 简晓玲[1] 杜民[1] 

机构地区：[1]国土资源部海底矿产资源重点实验室广州海洋地质调查局,广州510075

出　　处：《沉积学报》2015年第3期561-567,共7页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目"北黄海盆地构造热机制与成烃效应"(批准号:41302100)资助

摘　　要：北黄海盆地是我国近海勘探及研究程度均较低的中新生代叠合断陷盆地,而东部坳陷是其内最具油气勘探前景的二级构造单元。通过岩芯观察与测井相分析,结合三维地震资料,认为东部坳陷中生界主要发育扇三角洲、辫状河三角洲、三角洲与湖泊沉积。受构造演化阶段的制约,不同时期具有不同的沉积演化特征。其中中侏罗世处于湖盆的初期断陷期,半深湖—深湖亚相发育,仅在坳陷边缘见少量小规模的扇三角洲沉积。晚侏罗世处于断陷扩展期,整体为一个完整的湖进—湖退旋回,早期北部缓坡发育三角洲沉积,南部及东部陡坡见扇三角洲沉积,中后期则由于湖平面上升,发育暗色泥岩为主的湖泊沉积,晚期北部缓坡见小规模三角洲前缘沉积。早白垩世处于断陷萎缩期,垂向发育2个正旋回沉积序列,其中旋回下部以扇三角洲、辫状河三角洲相为主,向上渐变为滨浅湖沉积。North Yellow Sea Basin is a typical Meso-Cenozoic superimposed fault basin,which has very weak exploration and research in the offshore of China. The Eastern Depression is the secondary building unit which has the best exploration foreground in North Yellow Sea Basin. According to the core observation and logging facies analysis,combined with 3D seismic data,it is considered that fan delta,braided-river delta,delta and lake developed in the Mesozoic in Eastern Depression. Restricted by structural evolution,there was different sedimentary evolution in different tectonic phase in Mesozoic. Middle Jurassic was in the period of initial graben faulting. The sedimentary types were mainly semi-abyss and abyss. There were few fan deltas in depression margin. Late Jurassic was in the period of faulting extension. The vertical lithological sequence was an integral depositional cycle of progradation-retrogradation.There were delta in north gentle slope and fan delta in abrupt slope in early stage. Owing to uprising of lake level,there developed undercompensation lake facies whose lithology is mainly dark mudstone. North gentle slope developed small-scale delta front. Early Cretaceous was in the period of faulting abortion,and there were two normal cyclic depositional sequences. The sedimentary types of each cycle were mainly fan delta,braided-river delta in lower part,and shore-shallow lacustrine upward.

关 键 词：北黄海盆地 东部坳陷 中生界 沉积相 沉积演化 

分 类 号：P618.13[天文地球—矿床学]