南海北部新生代构造演化序列及其油气成藏意义  

Cenozoic Tectonic Evolution Sequence in Northern South China Sea and Its Oil/Gas Singificance

作　　者：吕宝凤[1] 殷征欣[1] 蔡周荣[1] 万志峰[1] 

机构地区：[1]中山大学海洋学院,广东普通高校海洋石油勘探开发重点实验室,广州510006

出　　处：《地质学报》2012年第8期1249-1261,共13页Acta Geologica Sinica

基　　金：国家重点基础研究发展规划(973)项目(编号2009CB219401)资助的成果

摘　　要：本文从构造地质学的基本理论出发,在综合分析板块作用、壳幔作用、岩浆热事件、构造变形、沉积作用等地质作用特点及其相互印证与制约关系的基础上,梳理了南海北部新生代主要构造事件和构造演化序列,提出受欧亚、印澳、太平洋3大板块的共同影响,南海北部新生代主要构造运动划分为礼乐运动、西卫运动一幕、西卫运动二幕、南海运动、南沙运动5次较为合适。其中礼乐运动使南海北部进入裂陷发展阶段,并产生NE走向小型断陷;西卫运动一幕使断陷进一步扩展;西卫运动二幕使南海北部由断陷向断坳转变,断陷走向向NEE向转变;南海运动使南海北部进入坳陷发展阶段;南沙运动使南海北部进入差异性区域沉降阶段,构造格局基本形成。南海北部这种构造演化序列造就了前古近系、古近系、新近系3层含油气结构层系及始新统湖相、渐新统湖相—湖沼相及海陆过渡相和中新统海相3套烃源岩,围绕3套烃源岩可形成"上生下储上盖"、"自生自储自盖"与"下生上储上盖"3类成藏组合和背斜、古潜山、地层-岩性等多种类型的油气藏及其复式油气聚集带。Based on the basic theory of tectonic geology, this study analyzed major tectonic events and tectonic evolution sequence in the Cenozoic through comprehensive investigation of geological effects such as plate movement, crust-mantle effect, magmatic thermal events, tectonic deformation and deposition, and their geological process and restriction relation. It is proposed that the major tectonic movements in the north South China Sea, which were affected jointly by Eurasian, Indo-Australian, and Pacific plates, consisted of five tectonic events in Cenozoic period. Lile movement, Xiwei movement I episode, Xiwei movement II episode, Nanhai movement and Nansha movement. The Lile movement led the north South China Sea into rifting stage and produced small NE-trending faulting. The Xiwen movement I episode further expanded faulting while the Ⅱ episode caused the transform of north South China Sea from rifting to faulting and then to NEE-trending faulting. The Nanhai movement pushed the north South China Sea into depression stage, while the Nansha movement triggered it into differential regional subsidence stage, thus forming the basic tectonic framework. Such a tectonic evolution sequence in northern South China Sea resulted in the formation of a three-layer hydrocarbon-containing structure system and three hydrocarbon source rocks. the Eocene lacustrine facies source rock, the Oligocene limnetic-transitional facies source rock and the Miocene marine facies source rock. The three sets of hydrocarbon source rocks formed three source- reservoir-caprock assemblages, several kinds of hydrocarbon accumulation and composite hydrocarbon accumulation zones such as anticlinal pool, paleo-buried hill pool, stratigraphic-lithologic pool and others.

关 键 词：南海北部 新生代 构造演化序列 油气成藏要素 复式油气聚集带 

分 类 号：P618.13[天文地球—矿床学]