【作者】 解习农； 孙志鹏； 张道军； 何云龙；

【Author】 XIE Xinong;SUN Zhipeng;ZHANG Daojun;HE Yunlong;China University of Geosciences;Zhanjiang Branch of CNOOC;

【机构】 中国地质大学； 中海石油(中国)有限公司湛江分公司；

【摘要】 中央峡谷体系是发育于南海西北陆缘的一条重要的深水沉积物输送通道,是深水区粗碎屑堆积带。中央峡谷平面上可分为头部、主体部分和尾部三个带,每个区带具有明显不同的沉积构成特征。琼东南盆地中央峡谷沉积充填主要发育两种沉积类型,即浊积水道-天然堤复合体和块体流沉积复合体。其中,浊积水道-天然堤复合体主要分布于峡谷早期和中期,块体流沉积复合体主要发育于峡谷晚期。研究认为中央峡谷形成始于晚中新世,而其中粗碎屑浊积水道沉积主要源于越东方向,细碎屑块体流沉积主要源自于盆地北部陆坡体系。中央峡谷发育演化可划分为了3个阶段:中央峡谷形成-侵蚀阶段、中央峡谷主要充填阶段和中央峡谷充填-消亡阶段。中央峡谷早期充填的多期次的浊积水道及天然堤复合体以粗粒沉积物为主,可构成琼东南盆地深水区良好的油气储层;中晚期以细粒泥质沉积为主的块体流沉积可作为区域良好的盖层。更多还原

【Abstract】 The Central Canyon system is an important sediment-transporting conduit with relative coarse-grained deposits developed on the northwestern continental margins of South China Sea.The canyon on the plane could be divided into three segments,canyon head,main body and tail part,and there is distinct depositional architecture in each segment.Two types of deep-water depositional systems occur in the central canyon of the Qiongdongnan basin,including turbidite channel-natural levee composite deposits and mass-transported deposits.Among them,turbidite channel-natural levee composite deposits are mainly developed in the early and middle stages of the canyon.Mass-transported deposits are mainly developed in the middle and late stage of the canyon.This study indicates the formation of the Central Canyon originated from the Late Miocene.Turbidity deposits mainly came from the East Vietnam,and mass-transported deposits mainly came from the northern continental slope on the Qiongdongnan basin.The evolution of the Central Canyon could be divided into five stages:the formation and erosion stage of the canyon,the main filling stage of the canyon,and the decaying stage of the canyon filling.Of them,multiple turbidite channel-levee complex deposits with relativecoarse-grained sandstones in the early and middle stages of the canyon are believed to be the good-quality reservoirs for hydrocarbon exploration in the deep-water area of northern margins of South China Sea,and mass-transported deposits with siltstones or mudstones in the middle and late stages of the canyon are taken as the good-quality caprocks.更多还原