【作者】 侯方辉；

【导师】 李三忠； 李刚；

【作者基本信息】 中国海洋大学 ， 海洋地质学， 2014， 博士

【摘要】 东海陆架盆地位于东亚大陆边缘，是一个叠置在华南陆块之上的中、新生代叠合含油气盆地。论文研究区主要位于东海陆架盆地南部，包括新生代的瓯江凹陷、雁荡低凸起、闽江凹陷、台北低凸起、基隆凹陷、台西盆地及新竹凹陷等构造单元，面积约12×104km2。由于前期研究重点放在新生代地层及构造，对东海陆架盆地南部中生代地层分布及构造特征并不清楚，严重制约了对华南大陆中生代构造格局及地球动力学过程的认识。基于上述问题，本论文充分收集整理了华南东部陆区和东海陆架盆地有关中生代地质文献资料，并实地考察了浙闽沿海中生界露头，参与东海陆架盆地南部16000km的二维地震剖面解释工作，编制了中生界厚度图、深度图、构造单元区划图、断裂体系图及平衡剖面图，系统研究了东海陆架盆地南部中生界分布特征，分析了中生代构造特征，并通过与华南陆区海陆对比研究，提出了东海陆架盆地中生代构造演化的3阶段模式。主要成果及认识如下：1．印支运动后，华南陆区中生代地层发育，东部的浙、闽、粤陆区主要发育有3个大的区域性不整合，即中侏罗世与晚侏罗世之间的不整合、早白垩世早期与早白垩世晚期之间的不整合、晚白垩世与古近纪之间的不整合，分别对应燕山期的3幕运动。2．东海陆架盆地南部地震剖面上可以识别出T02、T03、T04、T05、T06、Tg等6个地震反射波组，其中T02、T04、T05、T06和Tg为5个不整合面，将研究区划分为I、II、III、IV、V等5个地震层序，分别对应第四系～新近系、古近系、白垩系、侏罗系和前中生界。3．研究区中生界总体呈北东向展布，西部的瓯江—丽水断陷带内中生界厚约1000～2500m，最大残留厚度可达3000m，主要发育白垩系，缺失侏罗系。雁荡低凸起带北部残留了400～1500m厚的白垩系，南部残留了200～800m厚的白垩系。中部的闽江—厦澎斜坡带内中生界厚约2000～5000m，最大厚度5500m，侏罗系和白垩系皆有分布。东部的基隆—新竹断陷带内广泛发育了侏罗系和白垩系，中生界厚约3000～7000m，最厚可达8000m，为中生界沉降中心。从侏罗纪到白垩纪中生界沉降中心具有自西向东迁移规律。4．通过区域海陆对比把海域内原来属晚侏罗世的厦门组划为中侏罗世，提出东海陆架盆地可能缺失晚侏罗世-早白垩世早期的火山-沉积地层。5．根据沉积特征及变形特征将东海陆架南部中生代盆地划分为瓯江－丽水断陷带、雁荡低凸起带、闽江－厦澎斜坡带和基隆－新竹凹陷带4个次级中生代构造单元；中生代主要发育北东－北北东向和近东西向断裂，以及4类构造样式；东海陆架中生代主要经历了基隆运动、渔山运动和雁荡运动，大致对应华南陆区的印支运动、燕山Ⅱ幕运动和燕山Ⅲ幕运动。6．通过地震剖面对比解释，厘定了东海陆架侏罗纪和白垩纪残留盆地的边界，侏罗纪盆地为坳陷型盆地，白垩纪盆地为断陷型盆地。7．通过构造演化剖面恢复并结合区域海陆构造对比，将东海陆架盆地南部中生代演化过程划分为晚三叠世－中侏罗世被动大陆边缘坳陷盆地阶段、晚侏罗世－早白垩世早期安第斯型主动大陆边缘岛弧隆升阶段、早白垩世晚期－晚白垩世西太平洋型主动大陆边缘弧后伸展盆地阶段。更多还原

【Abstract】 The East China Sea Shelf Basin is located on the east Asia continental margin. It is aMesozoic-Cenozoic composite basin superposed on the South China Block. The research area islocated on southern of East China Sea Shelf Basin composed of Oujiang Sag, Yandang Heave,Minjiang Sag, Taibei Heave, Jilong Sag, Taixi Basin and Xinzhu Sag, with an area of12×104km2.Due to previous studies focus on the Cenozoic strata and tectonic, the Mesozoic strata andtectonic characteristics is not clear, which constrict understanding the Mesozoic tectonicframework and geodynamic process of South China continent. Based on the above problems, thispaper fully collect the Mesozoic geological literature, engage in the Mesozoic outcrop field trip toZhejiang Province and Fujian Province, and participate in16000km2D seismic profilesinterpretation work. The research work includes: establishing the sequence stratigraphicframework; obtaining formation thickness and subsidence migration patterns; dividing tectonicunits, analyzing the characteristic of the faulting system and its control of the tectonic units；clarifying the superposition of different tectonic stress fields by tectonic style inversion；magmaage statistics and summarizing the magma migration patterns；understanding tectonic deformationfeatures in different evolutionary stages by balanced section construction and quantitativerecovery; analysis of tectonic evolution and history of basin filling and Mesozoic prototype basinrestoration. The main achievements are as following:1. The Mesozoic strata developed well in land area of South China Block after the Indosinianmovement. There are three main regional unconformity in the eastern land area of ZhejiangProvince, Fujian Province, and Guangdong Province, e.g. the unconformity between middleJurassic and and late Jurassic, the unconformity between early and late early Cretaceous, and theunconformity between late Cretaceous and Paleogene. The three unconformity correspond to threeorogenic movement of Yanshan epoch.2. On the seismic profiles of southern East China Sea Shelf Basin, six seismic reflectionwaves can be identified, e.g. T20, T30, T40, T50, T60and Tg. The T20, T40, T50, T60and Tgare fiveunconformity surface, corresponding to Quaternary-Neogene, Paleogene, Cretaceous, Jurassic andpre-Mesozoic.3. The Mesozoic strata distribute in NE orientation totally in study area. In the Oujiang-Lishui sag belt, the Cretaceous strata have a thickness of1000-2500m, with a maximumresidual thickness of up to3000m. The Cretaceous strata has a residual thickness of400-1500m innorthern Yandang low Heave belt and200-800m in southern. The Jurassic and Cretaceous strata inMinjiang-Xiapeng slope belt are about2000-5000m thick, with a maximum thickness of5500m.The Jurassci and Cretaceous strata are developed extensively in Jilong-Xinzhu Sag belt. TheMesozoic thickness is about3000-7000m, with a maximum thickness of up to8000m. Thesedimentation center migrate from the west to the east in Mesozoic Epoch.4. Through regional sea-land contrast, the paper put forward that the Xiamen Formationbelong to middle Jurassic, the possible loss of volcanic-sedimentary formation during late Jurasscito early Cretaceous in the East China Sea Shelf Basin.5. According to sedimentary characteristics and deformation characteristics, the Mesozoicbasin of East China Sea Shelf Basin can be divided into four secondary Mesozoic tectonic units,e.g. Oujiang-Lishui Sag belt, Yandang low Heave belt, Minjiang-Xiapeng slope belt andJilong-Xinzhu Sag belt. There mainly develop NE-NNE orientation fault and four kinds oftectonic style in Mesozoic epoch. The East China Sea Shelf Basin mainly experienced JilongMovement, Yushan Movement and Yandang Movement, roughly corresponding to the IndosinianMovement, Yanshan II phase Movement and Yanshan III phase Movement in South China Block.6. Through the interpretation of seismic profiles, the paper reture to the boundary of theJurassic and Cretaceous prototype basin, the Jurassic for depression basin and cretaceous for faultdepression basin.7. Through the structural evolution section recovery and combined with regional sea-landtectonic contrast, the Mesozoic evolution process is divided into three stage: the passivecontinental margin depression stage in the late Triassic-middle Jurassic, the Andean activecontinental margin arc uplift stage in the late Jurassic-early Cretaceous, and the West Pacificactive continental margin back-arc stretch basin stage in the late early Cretaceous-late Cretaceous.更多还原