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1.
湘西王村剖面寒武系浊积岩特征 总被引：2，自引：0，他引：2
湘西王村地区的寒武系代表江南斜坡相沉积序列，传统的下寒武统划分为杷榔组、清虚洞组；中寒武统划分为敖溪组、花桥组（下部）；上寒武统划分为花桥组（上部）、追屯组。其中，花桥组中浊流沉积最为发育，包括经典浊积岩和高密度浊流沉积两种类型，经典浊积岩的特征完全可以由鲍马层序来描述，但最常见的是AE、CDE组合等，其岩性主要为泥灰岩和泥晶灰岩。高密度浊流沉积粒度较粗，常含有细砾组分。常见粗尾粒序层理，也可见平行层理和中至大型交错层理，它们在垂向上构成似鲍马层序，如ABC等。浊流的主要沉积场所是斜坡的中下部，盆地边缘和盆地平原的浊流沉积较斜坡大为逊色。 相似文献
2.
通过大量的地震、钻井、录井、测井等资料分析,针对塔里木东部地区(简称塔东地区)上奥陶统进行了层序地层和沉积学方面的研究,结果表明,塔东地区上奥陶统可识别出1个二级层序、3个三级层序,自下而上分别是层序SQ1、SQ2和SQ3。层序SQ1识别出TST体系域,为一套深水盆地沉积,发育深水盆地、浊流沉积;层序SQ2可三分为LST、TST和HST体系域,LST体系域发育海退背景下的陆架边缘三角洲沉积,TST体系域为快速水进期,发育海相泥岩沉积,HST发育高水位滨岸沉积;SQ3发育浅海沉积,主要为三角洲—滨岸沉积体系。地层层序发育和沉积相分布受控于构造运动、沉积物源供给和相对海平面升降3个因素。3套层序的划分明确了塔东地区上奥陶统潜在的源岩层、储层和盖层的分布,其中层序SQ1为有利的烃源岩层、SQ2陆架边缘三角洲是潜在的有利储层,SQ3发育的滨岸砂岩为已经证实的油气藏。 相似文献
3.
利用层序地层学、沉积学原理和方法,对琼东南盆地古近系陵水组进行了层序划分和沉积体系时空配置关系的研究。建立了陵水组的层序地层格架,将其划分为Els3、ElS2和Elsl三个三级层序,其层序和体系域变化主要受控于凹陷内沉降中心的分布位置,沉积主要受控于盆地边缘的断坡带。每个三级层序低位体系域发育局限,海侵与高位体系域发育。沉积体系构成以扇三角洲、三角洲、滨海平原和浅海为主。探讨了沉积体系的演化,总结了其时空配置关系的特点。 相似文献
4.
塔里木盆地石炭系层序地层研究 总被引：1，自引：0，他引：1
应用地震、钻井、测井、岩心、露头及分析化验资料，将塔里木盆地石炭系划分为4个地震层序和6个沉积层序，其中Csq1、Csq2、Csq5层序为工型层序，Csq3、Csq4、Csq6层序为Ⅱ型层序，与标准的工型层序比较，盆地内Ⅰ型层序低位体系域以河流沉积体系和低位扇三角洲沉积体系为特征，缺失盆底扇、斜坡进积复合体等深水沉积体系；Ⅱ型层序中陆架边缘体系域不发育，主要的沉积体系以浅水碳酸岩台地和海岸平原为特征。石炭纪早期层序形成在起伏不平的剥蚀面之上，以填平补齐的充填沉积为主，中后期层序则发育在宽阔平坦的盆地内，层序地层学格架模式可用Van的被动大陆边缘模式来描述。 相似文献
5.
钻井和地震资料的丰富程度决定了储层预测研究精度。在多井区,利用地震属性及单井沉积相来确定平面沉积相,研究精度高;而在少井、无井区的海域,如何利用地震资料进行沉积储层研究,至今没有一个成熟的方法。渤海湾盆地渤中凹陷西环BZ3-1区钻井较少,完整钻遇到沙河街组的井则更少,以该区的沙河街组为例,基于地震多属性分析技术,结合古地貌分析,半定量确定研究区的沉积体系分布特征。通过三维可视化技术和切片技术的高精度三维沉积体系分析表明,由于三级层序发育于二级层序的不同体系域,会导致三级层序的体系域沉积体发育特征的不同。沙三段SQsl3层序发育于二级层序的低位体系域(LST),其低位体系域的扇体规模要远远大于高位体系域(HST)的扇体;SQs3m层序发育于二级层序的水进体系域(HST),其低位体系域三角洲朵体规模与高位体系域的三角洲朵体相当;SQs3u层序发育于二级层序的高位体系域,其高位体系域三角洲朵体规模远远大于低位体系域的三角洲朵体。 相似文献
6.
开展地震资料解释,分析上超、下超、顶超等地震反射终止关系、不整合面以及沉积趋势,识别出北康-曾母盆地中中新世以来14个三级层序界面。在层序界面内部,通过层序地层内幕结构刻画和原形剖面恢复,并结合地层堆砌方式,在北康-曾母盆地中中新世以来的层序地层内,划分了海进、高位正常海退、强制海退和低位正常海退4种成因单元。通过进一步研究该4种成因单元内地层结构和相分布关系,提出北康-曾母盆地中中新世以来的3种层序地层样式,即陆架边缘富砂型三角洲进积楔、退积型生物礁和陆架边缘富砂-富泥型退积楔,其中,沉积物源供应量充足且可容空间减小时,发育富砂的三角洲进积楔,陆架边缘-斜坡-盆地区域发育含砂深水扇;而可容空间增量远大于沉积物供应量时,发育退积型生物礁和富砂-富泥退积楔,斜坡-盆地区域含砂深水扇欠发育。 相似文献
7.
东海陆架盆地丽水凹陷古新统明月峰组发育典型的海底扇沉积,且已获得工业油气发现。该文利用现有地震地质资料,运用层序地层学理论方法,总结出丽水凹陷的海底扇沉积模式。海底扇沉积相标志包括:岩心主要表现为滑塌揉皱、包卷层理、泄水构造、块状砂岩、黑色泥岩撕裂屑、漂砾、砂注等构造;C-M图主要表现为重力流沉积特征;结构成熟度和成分成熟度中等—差。扇体地震反射结构主要为顺物源方向双向下超,垂直物源方向丘状反射特征,平面地震属性显示为典型扇形。丽水凹陷明月峰组由低位体系域、水进体系域和高位体系域组成,其中海底扇发育在低位体系域,在扇体近端发育多个下切谷,下切谷下切规模较大;坡折主要划分为断裂坡折和沉积坡折,其中断坡坡度较大,坡度7.2°左右,沉积坡折坡度较小,一般在5°左右,与下切谷相对应在谷口形成一系列的扇体,沟–坡–扇耦合关系良好。扇体规模较大,单个扇体面积最大124 km2,整个低位域由6个扇体组成,展示了丽水凹陷良好的岩性圈闭勘探前景。本次研究根据扇体的成因特点建立明月峰组低位域时期沟–坡–扇沉积模式,对指导勘探寻找出岩性圈闭和开创丽水凹陷油气勘探新局面具有一定意义。 相似文献
8.
西非下刚果盆地为一典型被动大陆边缘含盐盆地,下刚果盆地北部海域在白垩系海相碳酸盐岩层系获得丰富油气发现。研究区海相碳酸盐岩领域油气勘探面临的核心瓶颈问题,即白垩系碳酸盐岩的沉积模式、演化规律、储层特征以及沉积储层发育控制因素。综合钻井、地震、区域地质等资料,分析认为自下向上相对海平面的上升控制了沉积演化,沉积体系演化模式为浅海碳酸盐岩台地→浅海混积陆棚→半深海-海底扇。下刚果盆地碳酸盐岩储层展布在纵向及平面上均可以划分为内中外3个储层发育带,碳酸盐岩储层最主要发育于下白垩统Albian阶下Sendji组。该时期研究区整体发育浅海碳酸盐岩混积缓坡台地沉积体系,沉积亚相可进一步划分为混积滨岸、后缓坡、浅水缓坡以及深水缓坡4种类型,其中浅水缓坡亚相颗粒滩微相与后缓坡亚相台内浅滩、砂质浅滩微相储层最为发育。碳酸盐岩储层岩性组合主要包括颗粒灰岩、砂岩、砂质灰岩、白云岩4种类型;储层发育主要受沉积相带的控制,并受成岩作用的影响。 相似文献
9.
鄂尔多斯盆地西南缘奥陶系深水牵引流沉积 总被引：4，自引：0，他引：4
深水牵引流沉积是沉积学中的一个重要研究领域，包括内潮汐、内波沉积和等深流沉积两大类，主要发育于海洋深水区。深水牵引流沉积的研究起步较晚，目前主要集中于现代深海沉积和野外露头研究，对深埋地下的古代深水牵引流沉积发现较少，其所具有的油气潜能还不被人们所认识。本文论述了鄂尔多斯盆地西南缘奥陶系内潮汐沉积、等深流沉积的特征和沉积类型。内潮汐沉积是在研究区首次发现，以灰色中一细砂岩为主，部分为粗粉砂岩，单层厚十余厘米至数十厘米，砂岩以普遍发育双向交错纹理为特征。等深岩丘主要由3种碳酸盐等深岩组成，即砂屑等深岩、粉屑等深岩和灰泥等深岩，共发育有4种层序样式。最后，阐明了其油气勘探意义，并分析了其潜在的油气勘探价值。 相似文献
10.
随着勘探开发程度的不断升高,西湖凹陷保俶斜坡带平北地区中上始新统平湖组构造―岩性复合油气藏显示出较大的勘探潜力。然而,该区构造―岩性复合油气藏勘探基础薄弱,加之构造、沉积条件复杂,砂体展布规律不清,阻碍了该区的勘探进程。本文基于三维地震及钻井等资料,从构造、层序及沉积3个方面对砂体分布的控制因素进行分析,认为构造古地貌及可容纳空间控制地层厚度及沉积体规模;同沉积断裂坡折带控制砂体的展布;体系域类型控制砂体的时空配置,沉积微相类型控制砂体的储集物性。综合分析控砂因素认为:断陷期的平下下段和平下上段是构造―岩性圈闭发育的主要层段,勘探方向为低位体系域控沉积断层下降盘的地势低洼汇砂区,而平中上段有利的岩性圈闭勘探区为三角洲前缘砂地比低或三角洲前端发育的潮汐砂脊带。 相似文献
11.
The seismic stratigraphy, evolution and depositional framework of a sheared-passive margin, the Durban Basin, of South East Africa are described. Based on single-channel 2D seismic reflection data, six seismic units (A-F) are revealed, separated by major sequence boundaries. These are compared to well logs associated with the seismic data set. Internal seismic reflector geometries and sedimentology suggest a range of depositional regimes from syn-rift to upper slope and outer shelf. Nearshore and continental facies are not preserved, with episodic shelf and slope sedimentation related to periods of tectonic-induced base level fall. The sedimentary architecture shows a change from a structurally defined shelf (shearing phase), to shallow ramp and then terminal passive margin sedimentary shelf settings. Sedimentation occurred predominantly during normal regressive conditions with the basin dominated by the progradation of a constructional submarine delta (Tugela Cone) during sea-level lowstands (LST). The earlier phases of sedimentation are tectonic-controlled, however later stages appear to be linked to global eustatic changes. 相似文献
12.
Stratigraphic framework of sediment-starved sand ridges on a mixed siliciclastic/carbonate inner shelf; west-central Florida 总被引：1，自引：0，他引：1
J. H. Edwards S. E. Harrison S. D. Locker A. C. Hine D. C. Twichell 《Marine Geology》2003,200(1-4):195-217
Seismic reflection profiles and vibracores have revealed that an inner shelf, sand-ridge field has developed over the past few thousand years situated on an elevated, broad bedrock terrace. This terrace extends seaward of a major headland associated with the modern barrier-island coastline of west-central Florida. The overall geologic setting is a low-energy, sediment-starved, mixed siliciclastic/carbonate inner continental shelf supporting a thin sedimentary veneer. This veneer is arranged in a series of subparallel, shore-oblique, and to a minor extent, shore-parallel sand ridges. Seven major facies are present beneath the ridges, including a basal Neogene limestone gravel facies and a blue-green clay facies indicative of dominantly authigenic sedimentation. A major sequence boundary separates these older units from Holocene age, organic-rich mud facies (marsh), which grades upward into a muddy sand facies (lagoon or shallow open shelf/seagrass meadows). Cores reveal that the muddy shelf facies is either in sharp contact or grades upward into a shelly sand facies (ravinement or sudden termination of seagrass meadows). The shelly sand facies grades upward to a mixed siliciclastic/carbonate facies, which forms the sand ridges themselves. This mixed siliciclastic/carbonate facies differs from the sediment on the beach and shoreface, suggesting insignificant sediment exchange between the offshore ridges and the modern coastline. Additionally, the lack of early Holocene, pre-ridge facies in the troughs between the ridges suggests that the ridges themselves do not migrate laterally extensively. Radiocarbon dating has indicated that these sand ridges can form relatively quickly (1.3 ka) on relatively low-energy inner shelves once open-marine conditions are available, and that frequent, high-energy, storm-dominated conditions are not necessarily required. We suggest that the two inner shelf depositional models presented (open-shelf vs. migrating barrier-island) may have co-existed spatially and/or temporally to explain the distribution of facies and vertical facies contacts. 相似文献
13.
为了了解南中国海南部南沙群岛陆架-陆坡区中生代地层发育情况,作者通过综合分析该海区钻井、拖网及1987年以来采集的20000多公里的多道反射地震勘探等资料,得到了对该区中生界基本特征的如下新认识:空间分布上,南沙的中生界具有从北部的郑和-礼乐隆起南缘向南增厚的趋势;沉积岩相方面,东部三叠纪时为深海相,侏罗纪为浅海与三角洲相,白垩纪为浅海-内浅海相,而往西南部中生代的海水深度有变深的趋势;中-新生代变形上,在南沙西部的曾母盆地,中生界褶皱为复式的、非协调性的,南沙中部多为舒缓褶皱,东部仅在近巴拉望海槽地带出现小幅度的褶皱。结合围区中生界及特提斯构造域的发育特征,作者提出南沙地块上的海相中生界在大地构造上归属于残留在中特提斯洋北部减薄陆缘地壳上的中特提斯期海相沉积地层,是该海域油气资源勘探不可忽视的对象。 相似文献
14.
《Marine Geology》2001,172(3-4):265-285
Studies of latest Quaternary continental slope sediments at two localities on the east Australian margin have revealed markedly different responses to late Quaternary sea level fluctuations. Offshore of Noosa, in the sub-tropics, the sediment is predominantly a mixture of fine metastable carbonate, siliciclastic material, and pelagic carbonate. Important features of the stratigraphy include a siliciclastic-dominated facies deposited relatively slowly during the last glacial lowstand (sedimentation rate ≤8 cm/ka), and a calcareous facies, rich in metastable carbonate, deposited more rapidly during the late post-glacial transgression (sedimentation rates 15–24 cm/ka). Highstand and transgressive sedimentation rates are greater than lowstand rates by a factor of 2.5–6 due to increased shelf carbonate productivity after flooding of the mid-shelf. Off Sydney, in temperate latitudes, continental slope sediment is largely a mixture of fine siliciclastic material and pelagic carbonate. Mean sedimentation rates range from 2 to 5 cm/ka over the last four oxygen isotope stages, with mean glacial/interstadial rates higher than Holocene rates by a factor of ∼1.36. This largely reflects the transfer of siliciclastic mud from the shelf to the slope during sea level regression. In both localities, facies changes on the slope are not related to specific sea level states (e.g. lowstand facies, transgressive facies, etc.), but reflect instead the interaction of changing sea level with shelf morphology. 相似文献
15.
南黄海陆架沉积环境的聚类分析 总被引：2，自引：0，他引：2
张光威 《海洋地质与第四纪地质》1993,13(3):67-74
通过对描述性资料的Q型聚类、数据资料的R型和Q型聚类的定量分析,南黄海陆架可区分出三级环境和20个沉积亚环境,进一步探讨了1.70MaB.P.沉积环境序列。 相似文献
16.
High-frequency sequences composed of mixed siliciclastic-carbonate deposits may exhibit either vertical or horizontal changes between siliciclastics and carbonates. Vertical facies shifts occur between systems tracts and define a ‘reciprocal sedimentation’ pattern, typically consisting of transgressive/highstand carbonates and forced regressive/lowstand siliciclastics, although variations from this rule are common. Mixed systems with lateral facies change, usually typifying transgressive and/or highstand systems tracts, may exhibit proximal siliciclastics and distal carbonates or vice-versa, although variations may also occur along depositional strike. The marked variability of mixed siliciclastic-carbonate sequences makes the definition of a universal sequence stratigraphic model impossible, as the composition and geometries of systems tracts may change considerably, and sequence stratigraphic surfaces and facies contacts may vary in terms of occurrence and physical expression. However, some resemblance exists between siliciclastic sequences and mixed sequences showing lateral facies changes between siliciclastics and carbonates. In particular, these mixed sequences display 1) a stratal architecture of the clastic part of the systems tracts that is comparable to that of siliciclastic deposits, 2) a dominant role of the inherited physiography and of erosional processes, rather than carbonate production, in shaping the shelf profile, and 3) a local lateral juxtaposition of siliciclastic sandstones and carbonate bioconstructions due to hydrodynamic processes. These observations are helpful in predicting the location of porous and potential sealing bodies and baffles to fluid flow at the intra-high-frequency sequence scale, and ultimately they are useful for both petroleum exploration and production. 相似文献
17.
渤海南部表层沉积的相特征 总被引：1，自引：0，他引：1
通过海上调查及实验室分析,查明渤海南部表层沉积物在结构类型、矿物组合、生物组分及沉积构造等相特征方面具有明显的分区性。渤海南部存在五种沉积相:黄河水下三角洲相、陆架盆地相、海湾相、潮流浅滩相及古滨岸相。黄河水下三角洲相从河口延至水深15—20米处,沉积速率很高,沉积物富含碎屑云母及CaCo_3。陆架盆地相的沉积为粉砂质粘土,具有生物扰动构造。 相似文献
18.
关于南海北部深水重力流沉积问题的讨论 总被引：1，自引：0，他引：1
深水沉积主要泛指陆架以外的沉积,尤以沉积物重力流成因的沉积受到深水油气勘探界的关注,它的沉积成因、过程和相组成均与河流、三角洲、浅海等牵引流沉积有很大的差异。当前南海北部大规模深水勘探已经全面展开,正确认识深水重力流沉积具有重要意义,但由于我国油气勘探对深水重力流沉积缺乏勘探实践,目前对深水重力流沉积有不同的理解,如深水重力流沉积一定要在多深的水下沉积,深水重力流沉积的判识一定要有深水环境的标志,深水重力流沉积作用保留在地层中的沉积层理构造特征一定是重力流流态的等。通过南海北部深水实钻资料和沉积体系的研究,认为深水重力流沉积具有偶发而动、沿坡搬运、择低而积、有限分布的特点。陆架坡折带以外的粗陆源碎屑沉积以重力流沉积成因为主,低位体系域的重力流更易于发育砂岩储层。陆坡区深水重力流沉积的特点表明储层识别是深水勘探的关键工作。 相似文献
19.
Seismic and sequence stratigraphic architecture of the central western continental margin of India (between Coondapur and south of Mangalore) has been investigated with shallow seismic data. Seismic stratigraphic analysis defined nine seismic units, that are configured in a major type-1 depositional sequence possibly related to fourth-order eustatic sea-level changes, comprising regressive, lowstand, transgressive and highstand systems tracts. The late-Quaternary evolution of the continental margin took place under the influence of an asymmetric relative fourth-order sea-level cycle punctuated by higher frequency cycles. These cycles of minor order were characterised by rapid sea-level rises and gradual sea-level falls that generated depositional sequences spanning different time scales. During the regressive periods, dipping strata were developed, while erosional surfaces and incised valleys were formed during the lowstands of sea level. Terraces, v-shaped depressions, lagoon-like structures observed on the outer continental shelf are the result of the transgressive period. In the study area we have recognised a complex erosional surface that records a long time span during the relative sea-level fall (regressive period) and the following sea-level lowstand and has been reworked during the last transgression. We also infer that sedimentation processes changed from siliciclastic sedimentation to carbonate sedimentation and again to siliciclastic sedimentation, marking an important phase in the late-Quaternary evolution of the western continental shelf of India. We attribute this to an abrupt climate change at the end of the oxygen isotope stage 2, between the Last Glacial Maximum and the Bølling-Allerod event (14?000 yr BP). This sensitive climate change (warming) favoured the formation of reefs at various depths on the shelf, besides the development of Fifty Fathom Flat, a carbonate platform on the outer shelf off Bombay developed prior to 8300 yr BP. The highstand systems tracts were deposited after the sea level reached its present position. 相似文献
20.
泥质潮坪磁组构特征及其意义研究 总被引：3，自引：4，他引：3
在１９８８年－１９９３年期间，对河北歧口及上海南汇海岸带泥质潮坪现行滩面积浦西曹杨新村近代亚潮坪沉积剖面进行了沉积动力环境与沉积动力环境与沉积磁组构特征测量分析。现行开敞海岸同物源潮坪沉积磁且构参量量值特征显示出，其Ｋ值高滩为高值，低潮滩次之，中潮滩为低。亚近开敞海岸泥质潮坪沉积剖面磁组构测量结果；Ｋ值是区分潮坪沉积动力活动带的高分辨率标志；Ｐ、Ｌ、Ｆ、ｑ是分析潮坪沉积结构的分辨率标志；ｑ是分析潮 相似文献