摘要
南海北部陆缘地区中生代受太平洋板块对东亚大陆俯冲挤压作用,发生多期次不均衡隆升,表现为以琼海断裂和阳江—一统暗沙东断裂为界,基底呈现西老东新、侧向分块的3个阶梯式分布。而在垂向上则表现为不同分带结构特征,琼海断裂以西的琼东南盆地基底为两层结构,下部元古界,上部古生界,缺失中生界;琼海断裂与阳江—一统暗沙东断裂之间的珠江口盆地西部基底为不完全三层结构,中生界呈孤岛状分布;而阳江—一统暗沙东断裂以东的珠江口盆地东部基底则为三层结构,元古界、古生界、中生界均保存较好。对基底结构研究结果表明,在珠江口盆地东部潮汕坳陷及东沙隆起带分布有巨厚的中生界,发育大型宽缓褶皱带,并且具有较厚的暗色泥岩分布,烃源岩条件较好,而在基底之上厚度较大的古近系可作为与之配套的盖层。因此,借鉴台西南盆地成功的勘探经验,推测南海北部陆缘前新生代地层也具有良好的油气勘探前景。
The epicontinental area of the northern South China Sea was influenced by the subduction and compression of the Pacific plate towards the eastern Asia continent during the Mesozoic,as a result,it uplifted heterogeneously in multiple stages.Bounded by the Qionghai fault and the eastern Yangjiang-Yitongansha fault,the basement of this epicontinental area is younger from west to east,showing a distributional pattern of being laterally divided into three stepped blocks and vertically formed by various zonal structures.The basement of Qiongdongnan Basin,westward from the Qionghai fault,is composed of a two-layer structure with the Proterozoic as the lower unit and the Palaeozoic as the upper unit but a hiatus of the Mesozoic.The western basement of the Pearl River Mouth Basin,eastward from the Qionghai fault and westward from the Yangjiang-Yitongansha fault,consists of an incomplete three-layer structure with the Mesozoic distributed as isolated islands,while the eastern basement of the Pearl River Mouth Basin,eastward from the Yangjiang-Yitongansha fault,is made up of a complete three-layer structure with the Proterozoic,Palaeozoic and Mesozoic well preserved.The result achieved from the study on these basement structures has indicated that the Chaoshan depression and the Dongsha uplift zone in the eastern Pearl River Mouth Basin have regionally thick Mesozoic strata,in which large-scale broad and gentle fold belts are developed and relatively thicker dark mudstones are distributed,suggesting a fairly good potential of source rocks.Furthermore,thicker Paleogene fault-depression deposits overlying the basement are capable of serving as caprocks in a complete petroleum system.Therefore,pre-Cenozoic epicontinental strata of the northern South China Sea are of a good petroleum prospect.
出处
《石油学报》
EI
CAS
CSCD
北大核心
2011年第4期580-587,共8页
Acta Petrolei Sinica
基金
国家科技重大专项(2008ZX05025)
国家重点基础研究发展规划(973)项目(2009CB219400)
东北亚生物演化与环境教育部重点实验室
吉林大学"211"工程三期建设项目
2009年教育部基本科研业务经费联合资助
关键词
南海北部
基底
中生界
烃源岩
油气前景
northern South China Sea
basement
Mesozoic
source rock
petroleum prospect
