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1.
南黄海盆地是在前震旦系克拉通基础上发育的中、古生界海相与中、新生界陆相多旋回叠合盆地。通过地震资料解释,结合邻区钻井与区域地质资料,对南黄海盆地中部隆起中、古生代地层及其形成演化进行了研究,结果表明,南黄海盆地中部隆起沉积了较全的中、古生界海相地层,发育第四系—新近系、中—下三叠统青龙组、上二叠统、下二叠统—上泥盆统、中—下志留统,奥陶系—震旦系和前震旦系变质岩系等7套地震地质层序;主要经历了前震旦纪基底形成、震旦纪—早古生代克拉通发育、晚古生代—中三叠世稳定台地—陆内裂陷、晚三叠世—古近纪形成与抬升剥蚀及新近纪-第四纪坳陷沉降5个阶段。  相似文献   

2.
南黄海为新生代、中生代与古生代叠合盆地,发育了新生代-中生代碎屑岩地层和早中生代-古生代海相碳酸盐岩地层,部分夹碎屑岩地层.在对测井资料和苏北盆地的相关资料归纳分析的基础上,总结了南黄海沉积层的纵波速度特征,标定了地震反射界面和地震反射层序.  相似文献   

3.
黄海海域地质构造特征及其油气资源潜力   总被引:4,自引:0,他引:4  
综合前人的研究成果,利用2000年以来在黄海采集的综合地球物理资料,结合我国及邻国在该海域的钻井成果,分析和讨论了黄海地区从古生代至新生代的构造演化历史;对南、北黄海沉积盆地形成的构造背景和盆地的构造类型进行了研究,认为在古生代它们是台地相沉积,中生代和新生代是张裂盆地;通过对我们采集的地震剖面之分析和研究,认为盆地中的中生界和古近系发育了良好的烃源岩,新近系发育了良好的区域盖层,储层在盆地中普遍发育。因此,在南、北黄海沉积盆地中可以找到中、小型油气田。另外,对盆地中的古生界应加强研究,在保存较好并且中新生代沉积较薄的地方做探查工作,应该有一定的油气前景。  相似文献   

4.
论南黄海区的两个新生代盆地   总被引:4,自引:0,他引:4  
根据近年来在南黄海进行地质、地球物理调查的资料,人们习惯于将该区划分为千里岩隆起、北部拗陷、中部隆起,南部拗陷和勿南沙隆起等五个一级构造单元.且通常将北部拗陷、中部隆起、南部拗陷分别与苏北的盐阜拗陷,建明隆起、东台拗陷等构造单元划为一个盆地,即南黄海-苏北中、新生代盆地.关于盆地的定义,据朱夏同志的意见:是在某一相当长的地质时期和某一具体地理区域内、在一种构造成因的不规则面上、在比较均一的构造环境中,由一个或几个来源沉积物所形成的实体.据此概念,以及近年来物探和地质方面的资料,作者认为南黄海区是以中部隆起为界,分别在不同基础上形成的南北两个分割性实体,即北部拗陷是一个盆地;南部拗陷和苏北地区是另一个盆地,暂命名为南黄海北部盆地和苏北南黄海南部盆地(以下简称北部盆地和南部盆地)(图1).现就盆地的基底、基础构造层、第三纪沉积以及中部隆起的特征等,对该二盆地的差异性进行研讨.  相似文献   

5.
南黄海地区与上扬子地区海相中—古生界岩性地层对比   总被引:4,自引:0,他引:4  
海相油气勘探是近十年来我国油气勘探中的重点研究领域,受到越来越多的关注。南黄海地区分布着厚层的前新生代海相地层,为深入了解该套地层,通过收集南黄海盆地的钻井资料以及下扬子陆区的地层资料,将其与上扬子四川盆地的海相地层进行岩性对比和沉积演化分析,了解两套地层的异同性,认为南黄海盆地与上扬子四川盆地的海相中—古生界沉积演化在印支运动以前总体来说是"大同小异",均为以碳酸盐岩沉积为主的稳定沉积,只是在中—古生代构造运动改造时间、规模上存在着一定的差异,上下扬子地区的海相中—古生界具有充分的可比性。还就上下扬子地区的烃源岩特征和油藏保存条件差异等方面进行了简要阐述,这有助于通过借鉴四川盆地海相油气勘探的成功经验,评估南黄海海相地层油气潜力,探索南黄海盆地下一步油气勘探的方向。  相似文献   

6.
早寒武世下扬子陆块与华夏陆块均向北漂移并拼合成南方古陆,发生褶皱隆升,但对下扬子陆块北部(现今下扬子地区)影响不大,总体处于浅海台地相。因为早寒武世早期受上升流等因素的影响,下扬子地区早寒武世有机质来源丰富,在缺氧还原的沉积环境形成了优质烃源岩。下扬子地区下寒武统烃源岩呈NE向展布,受"一台两盆"构造格局影响存在2个沉积中心:一个在安吉—休宁深水陆棚区,厚度100~300m;另一个在泰州—盐城深水陆棚区,厚度50~150 m。海侵主要来自东北方向,烃源岩向东北方向减薄。从陆域烃源岩厚度分布趋势看,南黄海盆地烃源岩厚度应在50~200m之间。中生代南方古陆与华北陆块拼合形成中国大陆时,对下扬子古生代形成的油气藏产生了严重的破坏。台缘相烃源岩厚度大、埋深大、生烃早,生成的油气藏在中生代南北陆拼贴期遭到破坏,是现今古油藏的烃源供给者。我们推测南黄海下寒武统为台地相沉积,埋藏相对较浅,热演化程度相对较低,大部分烃源岩可能在燕山中—晚期发生过二次生烃,有利于常规油气藏的保存。  相似文献   

7.
南黄海盆地发育于前南华纪变质基底之上,是一个大型叠合盆地,经历了多期成盆和多期构造改造,形成了海相盆地和中新生代断陷盆地叠合改造型残留盆地。盆地演化历经南华纪—早、中三叠世海相地层发育期、晚白垩世—古近纪箕状断陷发育期和新近纪—第四纪坳陷发育期,为一典型地台—断陷—坳陷多层结构的复合型盆地。通过对地震资料解释、区域地质构造特征分析,综合烃源条件和后期保存条件,探讨了南黄海盆地油气远景。  相似文献   

8.
南黄海盆地是中-古生代海相沉积盆地与中-新生代陆相沉积盆地相叠加的大型沉积盆地,其油气调查与勘探始于20世纪60年代初,经历了陆相盆地调查与勘探、探索与研究、海相盆地勘查3个阶段。由于地震地质条件复杂、盆地演化历史复杂、地质构造复杂、勘探程度相对较低,50多年的调查与勘探未获得商业性油气发现。经过2005年以来的长期地震调查技术攻关,初步形成了以"高覆盖次数、富低频信号、强震源能量"的采集技术和"高分辨率、富低频成分、强反射能量"的处理技术相结合的盆地深部"高富强"地震探测技术,并获得深部海相层的有效地震反射。近年来的进一步调查和研究发现:(1)南黄海盆地不仅是扬子板块在海域的延伸,而且是下扬子地块的主体;(2)南黄海盆地与四川盆地在中-古生代海相盆地沉积时期具有相同的沉积建造和沉积演化历史;(3)南黄海陆相中-新生界以下残留有巨厚的中-古生代海相地层,存在可追踪对比的三套地震反射标志层组,据此建立了中-古生代海相沉积层的地震层序;(4)发育下寒武统荷塘组(或幕府山组)、上奥陶统五峰组-下志留统高家边组、上二叠统龙潭组-大隆组三套优质烃源岩,三套完整的生储盖组合,具备形成大型油气田的物质基础;(5)理论模拟和包体分析表明,海相中-古生界存在多源多期成藏特征;(6)崂山隆起是海相下古生界油气远景区,勿南沙隆起是海相上古生界的油气远景区;(7)崂山隆起高石稳定带是有利勘探区带,是寻找类似于四川盆地"威远型"和"安岳型"油气田的重要地区;(8)高石3号构造是古生界的首选钻探目标。下一步工作重点是实施以下古生界为主要目的层的参数井钻探,建立区内完整的中-古生代地层层序,获取资源评价参数,实现南黄海油气调查的战略发现和勘探认识突破。  相似文献   

9.
南黄海盆地不仅是扬子地台在海域的延伸,而且是下扬子地块的主体。南黄海盆地中—古生代海相沉积建造与四川盆地相似,具有与威远、安岳、五百梯、焦石坝、普光、龙岗等大型、特大型油气田相同的含油气层位,发育3套区域性烃源岩和3套完整的生储盖组合,油气资源潜力巨大。崂山隆起是海相下古生界的油气远景区,勿南沙隆起是海相中—古生界的油气远景区。  相似文献   

10.
南黄海中、古生界油气勘探前景   总被引:9,自引:2,他引:9  
近几年少量的地球物理勘探工作表明,南黄海印支面以下存在厚达5000m以上的海相中,古生界,而且保存远比苏北陆区好,是南黄海新的勘探领域,中部隆起和勿南沙隆起稳定,面积大,有望找到大中型油气田,是具有远景的勘探新区。南黄海的油气勘探,中部隆起和勿南沙隆起应注意寻找与两个不整合面有关的,上有盖层封堵的非构造型内幕原生油气藏,在有利凹陷区以及隆起与坳陷接合部位应注意寻找中,上古生界再生油气藏;北部坳陷在注意寻找陆相中生界油气藏的同时还应注意寻找断块潜山型海相中,古生界再生油气藏。  相似文献   

11.
The interdependence between the seismo-acoustic properties of a marine sediment and its geotechnical/physical parameters has been known for many years, and it has been postulated that this should allow the extraction of geotechnical information from seismic data. Though in the literature many correlations have been published for the surficial layer, there is a lack of information for greater sediment depths. In this article, a desktop study on a synthetic seafloor model illustrates how the application of published near-surface prediction equations to subsurface sediments (up to several tens of meters burial depth) can lead to spurious predictions. To test this further, acoustic and geotechnical properties were measured on a number of sediment core samples, some of which were subjected to loading in acoustically-equipped consolidation cells (oedometers) to simulate greater burial depth conditions. For low effective pressures (representing small burial depths extending to around 10 meters subsurface), the general applicability of established relationships was confirmed: the prediction of porosity, bulk density, and mean grain size from acoustic velocity and impedance appears generally possible for the investigated sedimentary environments. As effective pressure increases through, the observed relationships deviate more and more from the established ones for the near-surface area. For the samples tested in this study, in some instances increasing pressure even resulted in decreasing velocities. There are several possible explanations for this abnormal behavior, including the presence of gas, overconsolidation, or bimodal grain size distribution. The results indicate that an appropriate depth correction must be introduced into the published prediction equations in order to obtain reliable estimates of physical sediment properties for greater subsurface depths.  相似文献   

12.
Specific properties of the interannual sea level variations and annual tides in the Northwestern Pacific were studied. Several tide stations were monitored. The monthly mean sea level for the year of 1995 was analyzed at each tide station. A seismic event in 1995, some tectonic activity around the subject area, and the Kuroshio (the oceanic western boundary current) may possibly contaminate results which would have occurred from the astronomical annual tide alone.  相似文献   

13.
The effect of different fixation and storage protocols on the flow cytometric (FCM) simultaneous analysis of bacterioplankton and phytoplankton in coastal seawater samples (Mediterranean coastal lagoons) was investigated. FCM measurements (cell number, fluorescence and scatter characteristics) were obtained through DAPI staining. Three fixatives [glutaraldehyde (GA), formaldehyde (FA) and paraformaldehyde (PFA)] and two storage (3 months duration) methods (5 °C and −196 °C) were tested. Two dominant populations were detected in studied samples: bacteria and eukaryotic picophytoplankton. Adding fixatives (2% final concentration) appears necessary to obtain FCM exhaustive counts of all the bacteria and phytoplanktonic cells. This was related to the permeation effect of fixatives which allowed a better DAPI staining of the cells. Maximum fluorescence, i.e. optimal staining of the cells was obtained with FA or PFA, and significant lower fluorescences with GA. Fixed samples stored at 5 °C induced rapid cell loss. Only storage in liquid nitrogen of samples fixed with FA or PFA, allows mid-term (≥4 months) preservation of bacteria or picophytoplankton cell numbers, and limited evolution of DAPI-induced fluorescence and scatter characteristics.  相似文献   

14.
15.
《海洋学报(英文版)》2014,(9):F0003-F0003
<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology,  相似文献   

16.
The relationship between the flux of exotic benthic foraminiferal tests (i.e. tests which are supplied from open-sea sources alone) in a tidal inlet and that of bulk sediment was analysed, which can be expressed as two first-order linear equations. According to this relationship, in order to determine net sediment transport directions in the entrance, the test concentration in surficial sediments of the tidal basin can be compared against a ‘ critical level ’. The critical level is determined for the conditions that no net transport of bulk sediment is present within the entrance. If the observed concentration (averaged over the tidal basin) is higher than the simulated critical level, then the net sediment transport is directed to landward. This method is applied to the analysis of net sand transport at Christchurch Harbour, a tidal inlet system located in southern England. In this investigation, concentrations of exotic foraminiferal tests in the surficial sediments of the tidal basin and ebb tidal delta area were obtained from the analysis of sea-bed sediment samples. A series of probable critical levels were calculated based upon the data sets with regard to: (1) sediment discharge from the rivers; (2) magnitude of sediment discharge within the entrance during the ebb; (3) the test concentration outside the harbour; (4) the thickness of the moving layer; and (5) two parameters associated with dispersive processes. The results show that the concentration in the tidal basin sediment is higher than a number of simulated critical concentrations for representative cases. Consequently, the high level of the concentration of exotic benthic foraminiferal tests within the harbour should be explained as a result of landward net transport of sands within the entrance.  相似文献   

17.
18.
The behaviour of an axially pre-loaded cylindrical member of an offshore structure, hit by a supply ship, has been investigated. The effects of axial pre-loading on the dynamic properties of members, the extent of damage and propagation of dynamic instability in the tubular members have also been investigated. Numerical models have been validated using available experimental data from the literature although these are mostly static with no pre-loading. Axial pre-loading was found to change the dynamic characteristics of some cylindrical members quite dramatically while it had no significant effect on others. The study examined whether there was any change in the behaviour between local and global modes when the loading was dynamic rather than static. The effect of damping on the dynamic instability of axially pre-loaded tubes under lateral dynamic loads was also studied. It was observed that for some geometries the quasi-static response can be used to define the boundary between bounded and unbounded dynamic responses. The main contribution of this study, compared with previous investigations reported in the literature, is that both pre-loading and dynamic effects have been included.  相似文献   

19.
Observations on seafloor features from subbottom profiling and seabed photography data show that the undisturbed and natural conditions before the benthic disturbance undergo a substantial change after operation of the disturber. The effects can be seen in the form of deep trenches and grooves, formed by the action of the sleds and the pumping of the sediment along its path, as well as sediment piles on either side of the track. Biological traces such as fecal coils, casts, tubes, burrows, and trails get obliterated in the areas of disturbance and resedimentation. The smooth, uniform nature of the seafloor observed in predisturbance phase shows microtopographic changes in and around the disturbed area as a result of sediment excavation and resettlement. Vertical mixing as well as lateral transport of sediment alter the geological, biological, physical, and chemical conditions on the seafloor, which need to be monitored over time to assess the process and the time taken for restoration of environmental conditions.  相似文献   

20.
Abstract. Long-term changes in the distributional patterns of commercial sponges ( Spongia spp. and Hippospongia spp.) within the West Indian Region indicates that: 1) commercial sponges had a widespread distribution throughout the whole West Indian Region and were ubiquitous in very shallow water until about the first half of the present century; 2) they were fished commercially not only in the traditional northern Caribbean sites (Florida, Gulf of Mexico, Bahamas) but also in the Greater ( e. g. , Hispaniola, Jamaica) and Lesser Antilles; and 3) they became extinct throughout most of the Lesser Antilles ( e. g. , Puerto Rico, Vieques, St. Thomas) sometime during the first half of this century. Mortalities of spongiids within the Antilles were found to differ from other marine mortalities in that: 1) species disappeared from a large region; 2) species vanished from different habitats and depths; and 3) natural populations never recovered. Species richness patterns suggest that commercial sponge genera ( Spongia and Hippospongia ) evolved under slightly cooler elimatic conditions than those found at present, and that these extinctions occurred as a direct or indirect effect of positive thermal anomalies in sea surface and atmospheric temperatures between 1900–1950. The concept that species diversity is stable on a regional scale is questioned.  相似文献   

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