东海陆架盆地南部中生代地层分布及构造特征研究
发布时间:2018-05-18 05:21
本文选题:东海陆架盆地 + 中生界 ; 参考:《中国海洋大学》2014年博士论文
【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。
[Abstract]:The continental shelf basin of the East China Sea is located on the continental margin of East Asia . It is a Mesozoic - Cenozoic superimposed petroleum - bearing basin superimposed on the continental margin of East China . The research area is mainly located in the southern part of the shelf basin of the East China Sea , including the Oujiang sag in the Cenozoic , the Yanao low - uplift , the Min River depression , the Taibei low - uplift , Keelung depression , Taixi basin and Xinzhu sag , etc . , with an area of about 12 脳 104km2 .
Based on the above - mentioned problems , this paper systematically studies the Mesozoic tectonic pattern and the geodynamic process in the southern China continental shelf basin . Based on the above - mentioned problems , this paper studies the Mesozoic tectonic characteristics of the East China Sea shelf basin and the two - dimensional seismic section interpretation work in the south of the East China Sea Shelf Basin . The paper studies the Mesozoic tectonic characteristics and the three - stage mode of Mesozoic tectonic evolution in the East China Sea shelf basin .
1 . After the Indo - China movement , there are three major regional inconformity in the Mesozoic strata in the southern part of the South China , namely , the inconformity between the Middle Jurassic and the late Jurassic , the inconformity between the early Cretaceous and the late Cretaceous , the inconformity between the early Cretaceous and the late Cretaceous , and the non - integration between the Late Cretaceous and the Early Cretaceous , which correspond to the three curtain movements of the Yanshan period respectively .
2 . In the southern seismic section of the East China Sea Shelf Basin , there are 6 seismic reflection wave groups , such as T03 , T04 , T05 , T06 and Tg . Among them , there are 5 unconformable surfaces , such as T04 , T05 , T06 and Tg , which are divided into five seismic sequences , namely I , II , III , IV , V , respectively .
3 . The Mesozoic boundary is about 1000 锝
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