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珠江口盆地?琼东南盆地深水区新生代构造沉积演化对比分析 总被引：1，自引：1，他引：0
南海北部陆缘记录了南海形成演化的历史,但是其新生代构造沉积演化特征在东段和西段的差异及其原因目前还不太清楚。本文分别在珠江口盆地和琼东南盆地的深水区选择了数口构造地理位置相似的井通过精细地层回剥分析,重建了两沉积盆地的沉积速率和沉降速率并结合前人研究成果进行了对比分析。研究结果发现,两沉积盆地在裂陷期的沉积和沉降特征基本相似,但是两者在裂后期的构造沉积演化特征差异明显。珠江口盆地深水区沉积和沉降速率都表现为幕式变化特征,其中沉积速率表现为“两快三慢”的特征而沉降速率表现为“两快一慢”的特征。琼东南盆地深水区的沉积速率表现为“地堑式”变化特征,但是沉降速率表现为“台阶式”上升的变化特征。琼东南盆地“台阶式”上升的沉降速率推测主要是受到海南地幔柱伴随红河断裂的右旋走滑而向西北漂移的影响,这也与南海西北部的岩浆活动以及周围盆地的沉降特征吻合。红河断裂在2.1 Ma BP的右旋走滑控制了琼东南盆地1.8 Ma BP以来的快速沉积和加速沉降分布。 相似文献
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琼东南盆地深水区东区凹陷带,即松南—宝岛—长昌凹陷,位于琼东南盆地中央坳陷东端。在大量地震资料解释的基础上,对38条主要断层进行了详细分析。获得以下认识:(1)琼东南盆地深水区东区凹陷带平面上表现为近EW向展布的平行四边形,剖面结构表现为自西向东由半地堑—不对称的地堑—半地堑有规律变化。(2)琼东南盆地深水区东区凹陷带断裂系统可划分控制凹陷边界断层、控制洼陷沉积中心断层和调节性断层3类。(3)琼东南盆地深水区东区凹陷带古近纪时期受到太平洋板块俯冲和南海海盆扩张的双重影响,构造应力场发生NW—SE→SN转变。构造演化可划分为3个阶段:～32Ma,应力场以区域性NW—SE向伸展为主,断裂系统以NE—SW向为主,控制凹陷边界;32～26Ma,以南海海盆近SN向拉张应力场为主,断裂系统以NWW—SEE向为主,断层活动控制凹陷沉积中心;26～Ma,区域性伸展与南海海盆扩张应力均逐渐减弱,NE—SW向和NWW—SEE向断裂继承性发育。(4)琼东南盆地深水区东区凹陷带内部主要断层在渐新统崖城组和陵水组沉积时期活动速率快,地形高差大、沉积水体深、沉积厚度大,控制了崖城组和陵水组的大规模沉积,有利于烃源岩的发育。圈闭以受断层控制的断鼻和断块为主,长昌主洼凹中隆起带发育2个最为理想的构造圈闭。 相似文献
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琼东南盆地海底地形地貌特征及其对深水沉积的控制 总被引：2，自引：0，他引：2
琼东南盆地位于南海北部大陆边缘西部,其深水区是重要的油气勘探新领域。利用琼东南盆地高密度的多道地震资料,阐明了琼东南盆地海底地形地貌特征,分析了盆地内深水沉积体的类型、特征、形成机制和空间展布,探讨了地形地貌对深水沉积的控制作用,对深入理解深水沉积过程,尤其是该区深水油气储层的预测具有重要意义。研究结果表明,琼东南盆地海底地形总体可以划分为陆架、陆坡和深海平原。在该地形地貌控制下,研究区内主要发育6种深水沉积体:浊流沉积、陆坡峡谷充填、滑塌沉积、滑移沉积、沉积物波和碎屑流沉积。进一步的研究表明,这些沉积体的空间发育部位和规模与陆坡的坡度有关。地形坡度通过控制重力流流体的流态产生各类型重力流沉积,进而控制了陆坡体系的调整过程。研究结果还表明,由于地形坡度的变化,重力流流态会发生相应变化,并进而导致各种类型重力流沉积在其形成过程中发生相互转化,其一般转化顺序通常为滑塌-碎屑流-浊流。 相似文献
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琼东南盆地深水区LS33-1-1钻井岩心微量元素地球化学特征及其沉积环境 总被引：1，自引：0，他引：1
为了研究琼东南盆地深水区的沉积环境及物源,对琼东南盆地深水区LS33-1-1钻井岩心样品的微量元素地球化学特征进行了分析,结果表明:研究区自渐新世以来沉积环境多变,物源复杂;在崖三段沉积早期,物源主要为当地或附近的基性玄武质火山碎屑,可能来自南海扩张引起的岩浆喷发活动;自崖三段沉积晚期(早于31.5Ma)以来,物源以陆源和海洋自生沉积为主,其中火山岩风化产物占有相当的比例。LS33-1-1钻井岩心沉积物的微量元素地球化学特征在距今31.5、28.4、25.5、23、16、8.2、5.5、2.7Ma均发生明显突变,表明沉积环境及物源均发生了明显的变化,反映了构造运动的影响。各地球化学指标在崖三段底部4 207m左右的突变,反映了琼东南盆地发生了较大规模的构造运动,造成了沉积物源由以基性火山碎屑为主转变为以陆源碎屑为主。在渐新世-中新世界线(23MaBP)附近,各项指标均表现出明显的突变,表明在ODP1148站及珠江口盆地深水区发现的物源突变事件(白云运动)也影响到了琼东南盆地深水区。 相似文献
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南海东南部陆缘发育多个新生代沉积盆地,其构造—沉积响应记录了南海形成演化的丰富地质信息。中中新世末S3界面是南海东南部新生代沉积盆地热沉降期的重要地质界面,但目前研究尚不充分,且对其地质属性也存在较大争议。在钻井资料约束下,通过对礼乐盆地和西南、西北巴拉望盆地二维地震测线的精细解释,结合钻井岩性资料,从地震相—沉积相、构造沉降速率以及沉积中心迁移等变化角度,系统总结了S3界面的特征。该界面是区域性不整合面,可全区域追踪解释,但在研究区不同构造位置界面特征具有明显差异:在盆地边缘和岛礁发育区界面具有显著的"下削上超"不整合现象,而凹陷内多表现为整合接触,但局部伴生水道下切现象;在西北、西南巴拉望陆架和陆坡区,界面上下存在岩性和沉积相突变现象,局部由半深水—深水相突变为滨—浅海相。构造沉降分析显示,中中新世研究区以区域快速沉降为主,中中新世末(S3界面时期)沉降速率开始普遍减小,可能与南海扩张结束后深部动力机制有关。厘定S3界面的形成时间约为12Ma,认为其可能与菲律宾岛弧与巴拉望岛碰撞造成的大规模抬升事件有关。另外,研究区S3界面之上发育的富砂和富碳酸盐岩的重力流沉积体系则可能是12.5Ma以来全球海平面相对下降的直接响应,期间多次区域性的海退有利于砂质和碳酸盐岩沉积物向深水区的搬运。 相似文献
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琼东南盆地新生代构造研究现状及展望 总被引：1，自引：0，他引：1
琼东南盆地属于南海北部陆缘拉张盆地,但是由于其不同的发育历史及红河断裂的影响,具有与东部陆缘盆地不同的构造特征。琼东南盆地和珠江口盆地在地壳结构、基底特征等方面存在差异,但是这种差异的原因还不清楚。新生代沉降速率发生多期变化,并存在裂后异常沉降、沉降延迟等现象,其形成机制尚需要进一步研究;平面上,构造具有迁移性,但是对不同地质时期的构造迁移方向仍存在不同的看法。盆地沉降中心和沉积中心经历了由裂陷期和裂后早期的较好重合到裂后晚期的逐步分离,直至完全分离的过程。盆地形成与地幔流的关系,以及红河断裂对盆地裂后沉降迁移的影响,也都是需要进一步确定的工作。鉴于以上各方面存在的问题,对琼东南盆地与南沙的共轭关系、盆地异常沉降、红河断裂及内部构造转换带对构造迁移的影响、以及琼东南盆地与珠江口盆地的比较等方面的研究是下一步工作的重点。 相似文献
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琼东南盆地井震地层对比分析及区域地层格架的建立 总被引：3，自引：3，他引：0
琼东南盆地历经断陷、断坳、裂后热沉降和裂后加速沉降等一系列的构造变动,沉积环境由始新世的滨海环境发展为现今的深水环境,形成了一套包括滨岸沉积、滨浅海沉积、陆架和陆坡沉积、以及半深海沉积的地层组合,具有良好的油气资源的生储盖条件,已成为当前油气资源勘探开发的重点区域。本文首先对盆地区域内钻井和地震剖面进行了主要地层界面(T20、T30、T40、T50、T60和T70)的识别和提取(点),继而结合连井地震剖面(线)和盆地区域过井地震剖面(面)对主要地层界面做了追踪对比分析,再依据古生物年代,建立了适用于琼东南盆地的区域地层年代格架。在琼东南盆地浅水区主要沉积了新近系地层(T60-T20),断裂基本不发育,地层厚度变化不大,极少有明显的上超和削截,局部地区发育有利于油气储集的三角洲沉积体系,表明琼东南盆地新近纪时期受构造作用影响较小。在深水区,新近系地层(T60-T20)和浅水区特征相似,仅反射特征有所不同;古近系地层(T100-T60)内部层序结构主要为楔状或近平行状,具有明显的上超和削截,地层厚度较大,断裂明显并导致地层错断,表明琼东南盆地深水区在古近纪时期主要受构造作用控制,并伴随着强烈的拉张和快速沉降作用,沉积环境主要为浅海。在近东西向的中央峡谷内存在有三期砂体:第一期砂体(井深3 528~3 336m,厚约192m)形成于距今11.6~5.5Ma(T40-T30),分布范围跨越中央峡谷的陵水-松南-宝岛段,沉积物构成包括浊积水道沉积、浊积席状砂、块体流沉积、深海泥质沉积、天然堤及漫溢沉积等;第二期砂体(井深4 100~3 900m,厚约200m)形成于距今5.5~4.2Ma(T30-T29),分布范围跨越中央峡谷的乐东-陵水段,以重力流沉积为主;第三期砂体(深度3 630~3 400m,厚约230m)发育于距今4.2~3.6Ma(T29-T28),分布于峡谷的乐东-莺东段,以浊积水道沉积为主。三期砂体在琼东南盆地中央坳陷带自东向西、由老到新依次展布,构成了良好的油气储层体。 相似文献
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Stress field modeling of northwestern South China Sea since 5.3 Ma and its tectonic significance 总被引：2，自引：1，他引：1
Tectonically, the northwestern South China Sea （SCS） is located at the junction between three micro-plates, i.e., the Indochina, South China and Zhongsha-Xisha micro-plates, and involves three basins, i.e., the Yinggehai Basin, the Qiongdongnan Basin and Xisha Trough in the east, and the Zhongjiannan Basin in the south. Since the Pliocene （5.3 Ma）, the Yinggehai Basin has experienced repeated accelerating subsidence, high thermal fluid, and widely developing mud-rich overpressure chambers, abundant mud diapers and crust-mantle mixed CO2. While a large central canyon was developed in the Qiongdongnan Basin, new rift occurred in the Xisha ~rough. These characteristics demonstrate a single tectonic unit for the northwestern SCS, for which we have undertaken stress field modeling to understand its plate deformations and sedimen- tary responses. Our results demonstrate that an extension tectonic event occurred after 5.3 Ma in theYingge- hal-Qiongdongnan-Xisha trough area, which is characterized by thinner crust C〈16000 m）, half-graben or graben structural style and thicker sedimentary sequences （〉3 500 m）. A new rift system subsequently was developed in this area; this event was mainly driven by the combined effects of different movement veloc- ity and direction of the three micro-plates, and the far-field effect of the continental collision between the Indian Plate and the Tibetan Plateau, and subduction of the Pacific Plate underneath the Eurasian Plate. 相似文献
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Bin Wang Fuliang Lü Shuang Li Jian Li Zhili Yang Li Li Xuefeng Wang Yintao Lu Taotao Yang Jingwu Wu Guozhong Sun Hongxia Ma Xiaoyong Xu 《海洋学报(英文版)》2021,40(2):29-41
High-resolution multichannel seismic data enables the discovery of a previous, undocumented submarine canyon(Huaguang Canyon) in the Qiongdongnan Basin, northwestern South China Sea. The Huaguang Canyon with a NW orientation is 140 km in length, and 2.5 km to 5 km in width in its upper reach and 4.6 km to 9.5 km in width in its lower reach. The head of the Huaguang Canyon is close to the Xisha carbonate platform and its tail is adjacent to the Central Canyon. This buried submarine canyon is formed by gravity flows from the Xisha carbonate platform when the sea level dropped in the early stage of the late Miocene(around 10.5 Ma). The internal architecture of the Huaguang Canyon is mainly characterized by high amplitude reflections, indicating that this ancient submarine canyon was filled with coarse-grained sediments. The sediment was principally scourced from the Xisha carbonate platform. In contrast to other buried large-scale submarine canyons(Central Canyon and Zhongjian Canyon) in the Qiongdongnan Basin, the Huaguang Canyon displays later formation time,smaller width and length, and single sediment supply. The coarse-grained deposits within the Huaguang Canyon provide a good environment for reserving oil and gas, and the muddy fillings in the Huaguang Canyon have been identified as regional caps. Therefore, the Huaguang Canyon is a potential area for future hydrocarbon exploration in the northwestern South China Sea. The result of this paper may contribute to a better understanding of the evolution of submarine canyons formed in carbonate environment. 相似文献
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Bin Wang Fuliang Lyu Shuang Li Jian Li Zhili Yang Li Li Xuefeng Wang Yintao Lu Taotao Yang Jingwu Wu Guozhong Sun Hongxia Ma Xiaoyong Xu 《海洋学报(英文版)》2021,40(3):84-93
High-resolution multichannel seismic data enables the discovery of a previous, undocumented submarine canyon(Huaguang Canyon) in the Qiongdongnan Basin, northwest South China Sea. The Huaguang Canyon with a NW orientation is 140 km in length, and 2.5 km to 5 km in width in its upper reach and 4.6 km to 9.5 km in width in its lower reach. The head of the Huaguang Canyon is close to the Xisha carbonate platform and its tail is adjacent to the central canyon. This buried submarine canyon is formed by gravity flows from the Xisha carbonate platform when the sea level dropped in the early stage of the late Miocene(～10.5 Ma). The internal architecture of the Huaguang Canyon is mainly characterized by high amplitude reflections, indicating that this ancient submarine canyon was filled with coarse-grained sediments. The sediment was principally scourced from the Xisha carbonate platform. In contrast to other buried large-scale submarine canyons(central canyon and Zhongjian Canyon) in the Qiongdongnan Basin, the Huaguang Canyon displays later formation time, smaller width and length, and single sediment supply. The coarse-grained deposits within Huaguang Canyon provide a good environment for reserving oil and gas, and the muddy fillings in Huaguang Canyon have been identified as regional caps. Therefore, Huaguang Canyon is potential area for future hydrocarbon exploration in the northwest South China Sea. Our results may contribute to a better understanding of the evolution of submarine canyons formed in carbonate environment. 相似文献
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The North Sea Basin has been subsiding during the Quaternary and contains hundreds of metres of fill. Seismic surveys (170 000 km2) provide new evidence on Early Quaternary sedimentation, from about 2.75 Ma to around the Brunhes-Matuyama boundary (0.78 Ma). We present an informal seismic stratigraphy for the Early Quaternary of the North Sea, and calculate sediment volumes for major units. Early Quaternary sediment thickness is > 1000 m in the northern basin and >700 m in the central basin (total about 40 000 km3). Northern North Sea basin-fill comprises several clinoform units, prograding westward over 60 000 km2. Architecture of the central basin also comprises clinoforms, building from the southeast. To the west, an acoustically layered and mounded unit (Unit Z) was deposited. Remaining accommodation space was filled with fine-grained sediments of two Central Basin units. Above these units, an Upper Regional Unconformity-equivalent (URU) records a conformable surface with flat-lying units that indicate stronger direct glacial influence than on the sediments below. On the North Sea Plateau north of 59°N, the Upper Regional Unconformity (URU) is defined by a shift from westward to eastward dipping seismic reflectors, recording a major change in sedimentation, with the Shetland Platform becoming a significant source. A model of Early Quaternary sediment delivery to the North Sea shows sources from the Scandinavian ice sheet and major European rivers. Clinoforms prograding west in the northern North Sea Basin, representing glacigenic debris flows, indicate an ice sheet on the western Scandinavian margin. In the central basin, sediments are generally fine-grained, suggesting a distal fluvial or glacifluvial origin from European rivers. Ploughmarks also demonstrate that icebergs, derived from an ice sheet to the north, drifted into the central North Sea Basin. By contrast, sediments and glacial landforms above the URU provide evidence for the later presence of a grounded ice sheet. 相似文献
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琼东南盆地深水区主要构造因素与成盆机制分析-地震解释与物理模拟实验 总被引：2，自引：1，他引：1
Located at the northwest continental slope of the South China Sea, the Qiongdongnan Basin bears valley-shaped bathymetry deepening toward east. It is separated from the Yinggehai Basin through NW-trend... 相似文献
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Geophysical investigations of crust-scale structural model of the Qiongdongnan Basin, Northern South China Sea 总被引：2，自引：0，他引：2
Ning Qiu Zhenfeng Wang Hui Xie Zhipeng Sun Zhangwen Wang Zhen Sun Di Zhou 《Marine Geophysical Researches》2013,34(3-4):259-279
Rifting of the Qiongdongnan Basin was initiated in the Cenozoic above a pre-Cenozoic basement, which was overprinted by extensional tectonics and soon after the basin became part of the rifted passive continental margin of the South China Sea. We have integrated available grids of sedimentary horizons, wells, seismic reflection data, and the observed gravity field into the first crust-scale structural model of the Qiongdongnan Basin. Many characteristics of this model reflect the tectonostratigraphic history of the basin. The structure and isopach maps of the basin allow us to reconstruct the history of the basin comprising: (a) The sediments of central depression are about 10 km thicker than on the northern and southern sides; (b) The sediments in the western part of the basin are about 6 km thicker than that in the eastern part; (c) a dominant structural trend of gradually shifting depocentres from the Paleogene sequence (45–23.3 Ma) to the Neogene to Quaternary sequence (23.3 Ma–present) towards the west or southwest. The present-day configuration of the basin reveals that the Cenozoic sediments are thinner towards the east. By integrating several reflection seismic profiles, interval velocity and performing gravity modeling, we model the sub-sedimentary basement of the Qiongdongnan Basin. There are about 2–4 km thick high-velocity bodies horizontal extended for a about 40–70 km in the lower crust (v > 7.0 km/s) and most probably these are underplated to the lower stretched continental crust during the final rifting and early spreading phase. The crystalline continental crust spans from the weakly stretched domains (about 25 km thick) near the continental shelf to the extremely thinned domains (<2.8 km) in the central depression, representing the continental margin rifting process in the Qiongdongnan Basin. Our crust-scale structural model shows that the thinnest crystalline crust (<3 km) is found in the Changchang Sag located in the east of the basin, and the relatively thinner crystalline crust (<3.5 km) is in the Ledong Lingshui Sag in the west of the basin. The distribution of crustal extension factor β show that β in central depression is higher (>7.0), while that on northern and southern sides is lower (<3.0). This model can illuminate future numerical simulations, including the reconstruction of the evolutionary processes from the rifted basin to the passive margin and the evolution of the thermal field of the basin. 相似文献
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Refining the model of South China Sea’s tectonic evolution: evidence from Yinggehai-Song Hong and Qiongdongnan Basins 总被引：2，自引：0，他引：2
The Cenozoic Yinggehai-Song Hong and Qiongdongnan Basins together form one of the largest Cenozoic sedimentary basins in SE Asia. Detail studying on the newly released regional seismic data, we observed their basin structure and stratigraphy are clearly different. The structure of the NW–SE elongation of the Yinggehai-Song Hong Basin is strongly controlled by the strike–slip faulting of steep Red River Fault. And the basement is covered by heavy sediments from the Red River. However, structures closely related with rifting are imagined on the seismic data from the Qiongdongnan Basin. This rifting and thinning on the northern continental margin of the South China Sea is necessary to be explained by the subduction of a Proto-South China Sea oceanic crust toward the NW Borneo block during the Eocene–Early Miocene. To test how the strike–slip faulting in the Yinggehai-Song Hong Basin and rifting in the Qiongdongnan Basin develop together in the northwest corner of the South China Sea, we reconstructed the tectonics of the northwest corner of the South China Sea and test the model with software of MSC MARC. The numerical model results indicate the South China Sea and its surrounding area can be divided into a collision-extrusion tectonic province and a Proto-South China Sea slab pull tectonic province as suggested in previous works. We suggested that offshore Red River Fault in the Yinggehai-Song Hong Basin is confirmed as a very important tectonic boundary between these two tectonic provinces. 相似文献