珠江口盆地花岗岩成因探讨及其对油气资源指示意义  

A discussion on the formation of granite in the Pearl River Mouth Basin and its implication to hydrocarbon resource

作　　者：刘安[1,2] 吴世敏[2] 

机构地区：[1]中国地质调查局武汉地质矿产研究所,湖北武汉430205 [2]中山大学地球科学系,广东广州510275

出　　处：《地学前缘》2011年第1期141-148,共8页Earth Science Frontiers

基　　金：国家重点基础研究发展计划"973"项目(2007CB411706-05);国家自然科学基金项目(40576025);中国地质调查局计划项目(1212010782005)

摘　　要：珠江口盆地燕山期花岗岩地球化学、地球物理等特征分析表明,其形成缘于中生代太平洋板块向华南大陆的俯冲,并引起华南大陆边缘岩石圈等温面上隆及上地壳硅铝质岩石的多次重熔。花岗岩层形成后的区域性剥蚀作用导致盆地隆起部位花岗岩穹窿和背斜的形成;此后,新生代沉积物覆盖在花岗岩背斜和穹窿之上并形成披覆背斜,该类构造为珠江口盆地重要的含油气构造类型。在中生代时,东沙隆起及其以北具有高地温场,花岗岩发育的特点;南部坳陷带则表现低地温场和中生代沉积等特点。中生代烃源岩演化程度相对较低,它在新生代时期具备二次生烃的可能性。The analysis of the geochemical and geophysical characteristics of Yanshan Period granite in the Pearl River Mouth Basin suggested that the uplifting of the lithosphere isothermal surface and multiple melting of the upper crust,which resulted from the subduction of the Pacific plate under the South China plate,gave rise to the formation of the granite.The granite dome and drape anticline on the uplifting part of the basin was formed by the regional erosion and the sedimentation in the Cenozoic afterwards.The drape anticline was one of the most important tectonic types of oil and gas bearing structure in Pearl River Mouth Basin.The Dongsha Rise and its northern region are characterized by high-temperature geothermal field in the Mesozoic and the granite,while the southern depression is featured by lower-temperature geothermal field and the Mesozoic sedimentary.Owing to the low thermal evolution of source rock in the southern depression,there was a possibility that secondary hydrocarbon generation could occur in the Cenozoic.

关 键 词：原地重熔 珠江口盆地 花岗岩 披覆背斜 二次生烃 

分 类 号：P588.121[天文地球—岩石学] P618.13[天文地球—地质学]