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1.
万安盆地是南海重要的新生代含油气盆地之一,是较为典型的新生代走滑拉张盆地。以TACross的旋回层序地层学为指导,利用钻井、地震资料、岩心等各种实际资料,建立了万安盆地新生代层序地层格架,并对万安盆地的可容纳空间变化与层序形成的主要控制因素(构造沉降、海平面升降及沉积物供应)进行了综合分析研究。  相似文献   

2.
陆相断陷盆地的沉积可容空间变化规律控制着盆地的层序地层充填样式和生储盖发育规律,根据目前我国陆相断陷盆地的层序地层响应特征,将沉积可容空间的变化频率分为低频和高频两种类型。油气汇聚体系是陆相断陷盆地油气勘探的研究对象,根据油气聚集规模将其划分为大型、中型和小型等三种规模类型。具备不同层序地层充填样式的陆相断陷盆地一般发育不同规模类型的油气汇聚体系和相应的空间展布规律:低频率沉积可容空间变化的陆相断陷盆地可以发育大型、中型规模的油气汇聚体系;高频率沉积可容空间变化的陆相断陷盆地一般发育中型或者小型规模的油气汇聚体系,大型规模的油气汇聚体系欠发育。我国陆区陆相断陷盆地中的东营凹陷是低频率沉积可容空间变化的典型代表,东濮凹陷是高频率沉积可容变化的典型代表;海区陆相断陷盆地中的涠西南凹陷属于低频率可容空间变化的类型,海中凹陷属于较高频率可容空间变化的类型。  相似文献   

3.
陆架沉积层序的地层模式受控于构造沉降速率及其区域模式,处于活动构造背景和处于被动大陆边缘背景中的盆地具有极不相同的区域沉降模式。因此,要对基本层序地层模型进行修正。在缓坡前陆盆地中,构造活动一侧与被动边缘相比具有相反的沉降模式,即沉降速度向海方向降低。  相似文献   

4.
厄瓜多尔Oriente盆地南部区块沉积特征   总被引:3,自引:0,他引:3  
通过构造演化和地层发育特征分析,将厄瓜多尔Oriente盆地南部区块Napo组划分为4个层序。根据岩心中的潮汐层理、羽状交错层理、冲洗交错层理、具有大量贝壳等特征,识别研究区具有潮坪沉积环境。针对其沉积坡度缓,碎屑岩和碳酸盐岩互层沉积的特点,建立了缓坡混积陆棚边缘的沉积相模式,认为Oriente盆地南部区块Napo组发育有海岸平原、潮坪、局限台地和混积陆棚相。相序的垂向组合和平面迁移受海平面升降的控制,指出潮坪砂岩主要出现在各层序的陆架边缘体系域,水下浅滩砂岩出现在海侵体系域。从沉积角度看,潮汐水道砂体是最好的储层砂体。  相似文献   

5.
书海拾贝     
叠合盆地层序地层分析与构造古地理——以塔里木盆地为例林畅松,于炳松,刘景彦,等著科学出版社资环分社出版本书从构造多期活动的叠合盆地分析的角度出发,介绍了层序地层学与构造古地理研究的理论和方法,系统论述了塔里木盆地层序地层序列与构造古地理演化的基本特征及其对油气勘探的启示。  相似文献   

6.
利用高分辨率二维地震反射剖面及钻井资料,对南海北部双峰南陆坡区的构造层序及沉积充填特征进行了研究。根据地震不整合界面、构造发育特征及地层组合情况,将研究区地层从下至上划分为下、中、上三个构造层序。研究分析表明,构造活动、海盆扩张、相对海平面变化、火山活动及物源供给等因素在不同阶段因时而异地共同控制着各构造层序的沉积充填过程及演化。下构造层(Tg—T6)形成于一系列的半地堑结构断陷盆地,在湖泊相的沉积环境下,沉积体系受同沉积断裂控制明显,发育了冲积扇—扇三角洲—半深湖相沉积;中构造层(T6—T4)形成于西北次海盆扩张沉降构造背景,在陆坡缓慢沉降和火山喷发的双重影响下,造就了陆坡区特殊的几何形态结构,影响着沉积体系的发育,陆坡区中上部为浅海陆架边缘三角洲沉积,在陆坡区则以斜坡扇等相关沉积为主;上构造层(T4—T0)形成于相对海平面总体上升、西北次海盆由缓慢进入相对快速的沉降阶段,沉积作用受控于物质供应充分程度和深水作用,发育了以深水水道和滑塌体为沉积特征的深水沉积体系。  相似文献   

7.
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   

8.
南海曾母盆地新生代晚期构造沉降分析   总被引:5,自引:0,他引:5  
曾母盆地是一个NW向走滑型沉积盆地,新生代晚期经历了强烈沉降,平缓沉降,加速沉降和差异升降四个时期,其构造演化主要决于加里曼丹与南沙两地块间的相互作用所引起的NW向断裂的活动方式。  相似文献   

9.
南安盆地是南海南部重要的大型含油气盆地之一,深入分析其构造-沉积演化特征对盆地油气勘探具有重要的指导作用。结合已有研究成果,开展盆地二维地震资料解释,识别出南安盆地新生代以来5个主要的二级层序界面和4套地震层序。在层序地层格架下,根据地震反射特征识别出南安盆地楔形、S型(丘状)等5类地震相类型;砂包泥岩、砂泥岩互层等7类地震岩相类型以及扇三角洲、河流三角洲等8类主要沉积相。综合盆地构造演化特征,南安盆地新生代以来主要分为4个阶段:初始裂陷阶段、主裂陷阶段、断拗转换阶段和拗陷热沉降阶段。其中,中中新世以前为盆地裂陷阶段,发育陆源碎屑沉积,早期为湖相沉积,晚期为滨浅海相沉积;中中新世以后为拗陷阶段,发育陆源碎屑沉积和碳酸盐岩沉积。通过油气成藏模式研究,南安盆地烃源岩发育且品质较好,有利储集相带纵向厚度大且横向范围广,区域盖层覆盖整个盆地,并形成了早期的自生自储和晚期的下生上储两类油气成藏系统。  相似文献   

10.
综合运用高精度层序地层学、构造一地层学方法,认为十屋断陷深层发育的各类隐蔽圈闭是下一步勘探工作的重要目标。同时,由于构造对沉积的控制作用,在断陷内部不同的构造部位具有不同的隐蔽圈闭分布特征。十屋断陷西部皮家地区、北部张家屯一八屋地区位于油气主要运移指向区,分别由断裂坡折带和以挠曲型褶皱为特征的弯折带控制的储集砂体十分发育,盖层及保存条件也十分优越,是深部原生岩性、地层油气藏最有利的勘探目标区带。  相似文献   

11.
Rift sequence stratigraphy   总被引:2,自引:0,他引:2  
Conventional sequence stratigraphy has been developed primarily for passive-margin basins. Despite the conceptual advances within the last 30 years, a suitable model for rift basins has not yet been devised. Many authors have attempted to adapt the passive-margin model to all other tectonic settings, including rifts, despite the fundamental differences in terms of the mechanisms controlling the formation and evolution of these sedimentary basins. Passive margins have their stratigraphic framework controlled largely by cyclic sea-level fluctuations superimposed on long-term thermal subsidence. By contrast, rift basins have their accommodation history strongly related to their mechanical subsidence regime, with episodic pulses of extension that create space for sediment accumulation at very fast rates. Stages of rapid mechanical subsidence are typically followed by longer periods of tectonic quiescence, when sediment supply gradually consumes and fills the available accommodation. This cyclicity results in depositional sequences that display overall progradational trends and coarsening-upward vertical stacking patterns. Sequence boundaries are often marked by sharp flooding surfaces related to the transgression of lacustrine or marine systems in response to rapid tectonic subsidence and the consequent ‘instantaneous’ generation of accommodation. As such, a typical rift depositional sequence starts with a flooding surface overlain by a relatively thin transgressive systems tract and a much better developed highstand systems tract. A renewed subsidence pulse leads to the drowning of the previous deposits and the start of a new depositional sequence. The strong asymmetry of the base-level curve resembles the shape of glacio-eustatic cycles, with fast transgressions followed by longer term regressions, although at potentially different temporal scales.  相似文献   

12.
通过对东海陆架盆地形成的动力学机制研究,分析了动力学机制控制下的盆地南部构造演化特征,提出构造演化对油气成藏的四个控制作用:(1)构造运动控制了盆地演化阶段与凹陷结构;(2)构造运动控制了盆地沉降中心迁移与地层分布;(3)构造运动决定了油气成藏关键时期和油气分带的差异性;(4)构造运动控制了油气聚集与分布。构造运动是盆地演化及油气成藏的主导因素,盆地构造演化结合油气地质综合研究是东海陆架盆地南部油气勘探工作的重点。  相似文献   

13.
High-resolution seismic reflection data are used in the identification of the stratigraphic succession filling Naples Bay, a tectonically active half-graben located in the extensional margin of the eastern Tyrrhenian Sea. The architecture of the basin infill is characterized by fourth-order depositional sequences correlated to Quaternary eustatic oscillations. These depositional sequences form aggrading and prograding stacking patterns bounded by tectonically enhanced unconformities. The changes that the stacking patterns undergo record variations in accommodation space rates. These variations are a result of the tectonic subsidence produced during the evolution of the half-graben. Received: 7 July 1998 / Revision received: 29 March 1999  相似文献   

14.
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   

15.
Three-dimensional seismic data and wireline logs from the western Niger Delta were analyzed to reveal the sedimentary and tectonic history of a major deltaic growth-fault depocenter comprising a kilometer-scale rollover anticline. The seismic units of the rollover show a non-uniform thickness distribution with their respective maximum near the main bounding growth-fault on the landward side of the system. This wedge-shaped sediment-storage architecture ultimately reflects the non-uniform creation of accommodation space in the study area that was controlled by 1) the differential compaction of the hanging-wall and footwall strata, 2) the lateral variation of fault-induced tectonic subsidence above the listric master fault, and possibly 3) local subsidence related to the subsurface movement of mobile shale reacting to loading and buoyancy. A sequential three-dimensional decompaction of the interpreted deltaic rollover units allowed to reconstruct and measure the compaction development of the rollover succession through time, documenting that sediment compaction contributed per depositional interval to between 25 and 35% of the generation of depositional space subsequently filled by deltaic sediments. The incremental decompaction of sedimentary units was further used to quantify the cumulative amount of accommodation space at and around the studied rollover that was created by fault movement, shale withdrawal, regional tectonic subsidence, isostasy and changes in sea level. If data on the regional subsidence and eustasy are available, the contribution of these basinwide controls to the generation of depositional space can be subtracted from the cumulative accommodation balance, which ultimately quantifies the amount of space for sediments to accumulate created by fault movement or shale withdrawal. This observation is important in that it implies that background knowledge on subsidence, stratigraphic age and sea-level changes allows to reconstruct and quantify fault movement in syn-tectonic deltaic growth successions, and this solely based on hanging-wall isopach trends independent of footwall information.  相似文献   

16.
南昆嵩地区是万安盆地西部负向构造单元,其中部N–S向断裂贯穿南北,独特的构造特征使其成为研究万安盆地西部构造演化与区域断裂走滑活动的窗口。将研究区沉积地层划分为3套构造层,通过回剥法绘制南昆嵩地区构造–沉积充填剖面,并计算南昆嵩地区构造沉降量以及构造沉降速率,论述南昆嵩地区构造演化史与沉降过程以及控制因素。研究结果表明:下部构造层和中部构造层中断裂组合样式主要为卷心型断层、“Y”型断层、阶梯状断层和高角度花状构造等,断裂延伸方向大致可分为:N–S向、W–E向和NE–SW向3种;上部构造层断裂不发育,为稳定沉积;在区域走滑断裂以及南海扩张运动的控制下,南昆嵩地区始新世以来构造演化经历4个阶段:初始裂谷期、伸展断拗期、走滑改造期和热沉降期,新生代地层构造性质也表现为以伸展与走滑作用为主–走滑断裂控制–热沉降的三段式转变。  相似文献   

17.
The demise of the high-relief, steep-slope, prograding Ladinian-Early Carnian carbonate platforms of the Esino Limestone (Central Southern Alps of Italy) is marked by subaerial exposure of the platform top associated with different erosional (mainly karst-related), depositional and diagenetic processes (Calcare Rosso). The exposure-related deposits consist of three major facies associations: 1) residual soils with thin lenses of conglomerates with black pebbles, and, locally, weathered vulcanites; 2) chaotic breccia lenses irregularly distributed in the uppermost part of the Esino Limestone carbonate platform, interpreted as collapse breccias in karstic setting: 3) inter-supratidal carbonate cycles with dissolution and development of paleosols and tepee structures.Facies distribution follows the sub-environments of the underlying Esino Limestone. Facies 1 and 2 typically characterize the core of the platform, covering the underlying inner platform facies. Facies 3 instead develops toward the edge of the platform, above reef-upper slope facies of the prograding facies of the Esino Limestone. The thickness of facies 3 decreases toward the core of the platform. Facies distribution reflects differences in the accommodation space and sedimentary processes from the rim (highest accommodation, favouring the deposition of peritidal-supratidal carbonates) to the core (reduced accommodation, causing pedogenesis and karstification) of the carbonate system.The observed thickness changes may be controlled by different factors: 1) syndepositional tectonics, 2) subsidence induced by magmatic activity or 3) differential subsidence controlled by the stratigraphic architecture of the Esino Limestone platform and adjoining basins. As evidence of tectonics was not observed and the presence of volcanic bodies is only documented tens of km away from the study area, the scenario involving the creation of accommodation space by compaction of the basinal sediments (resedimented, fine-grained calciturbidites) during the progradation of the carbonate platform is here investigated. Numerical modelling was performed to verify the compatibility of compaction-induced subsidence with the observed depositional architecture. The models were built to simulate the architectural evolution of the platform by progressively adding layers from deepest to shallowest, while compacting the underlying sediments, in order to evaluate compaction-induced subsidence (and accommodation space for the Calcare Rosso) after the deposition of the youngest platform strata. Modelling results allow us to conclude that the wedge geometry of the Calcare Rosso, deposited on top of the extinct Esino carbonate platform, can be explained by subsidence controlled by compaction of the basinal sediments present below the early-cemented, fast prograding platform slope deposits.  相似文献   

18.
In a broader application of sequence stratigraphic concept to a tectonically active margin setting, this study presents a sequence model that considers all three controls on sequence development (i.e. eustasy, tectonic movement and sediment supply) as independent variables. The model introduces six sequence types (A to F) including type 1 and type 2 sequences defined in the original Exxon scheme. Each sequence shows a variety in number and stacking pattern of its constituent parasequence sets reflecting combined effects of accommodation change and sediment supply. This model is applied to a seismic sequence analysis of the shelf–slope system (middle to upper Miocene) in the southwestern margin of Ulleung Basin which has experienced significant crustal deformation during the Tertiary back-arc opening and subsequent closing of the East Sea (Sea of Japan). The model application delineates four sequence types whose development is closely associated with the tectonic evolution of the Ulleung Basin margin. During the back-arc opening (early to middle Miocene), type A and B sequences were emplaced as a result of steady creation of accommodation space due to a rapid subsidence combined with a tectonic-controlled high to moderate rate of sediment supply. The sequences associated with the extensional tectonism are characterized by active progradation and aggradation without forced regressive phases. In the initiation stage of back-arc closure (middle to late Miocene), subsidence rates were significantly reduced because of a widespread contractional deformation, while subaerial erosion of the uplifted thrust belt resulted in an increase in sedimentation rate. As a result, steady prograding type-E sequences were formed by alternating normal and forced regressions. During the quiescent phase of back-arc closure in the late Miocene, rise-dominant fluctuating relative sea-level change and moderate to low sediment supply gave rise to type-F sequences (similar to type-1 sequences of the Exxon group) reflecting a major control of eustatic sea-level change.  相似文献   

19.
东海的形成与构造演化   总被引:1,自引:0,他引:1  
东海地区构造演化的地球动力学背景处于晚三叠世以来古亚洲大陆形成、太平洋板块向欧亚大陆俯冲及印度板块向欧亚大陆俯冲的远程效应共同作用下。东海的海洋沉积环境是在上新世以来持续的构造沉降、弧后裂谷作用及全球海平面上升作用下形成的。东海地质构造的剖析及其形成演化的研究,对于理解亚洲地形现代地形格局的形成及大江大河的演化具有重要意义。  相似文献   

20.
According to widely accepted sequence stratigraphic and fill-and-spill models, sedimentary cyclicity along continental margins is modulated by relative sea-level change, whereas smaller-scale intraslope accommodation is controlled by the filling of pre-existing bathymetric depressions. Although these concepts are presumed to apply to shelf-to-slope settings regardless of grain size, we have tested both hypotheses in the mud-prone lower Pliocene to Holocene of offshore Louisiana, Gulf of Mexico, and reach different conclusions. We determine that over the last ∼3.7 Myr, differential accumulation and accompanying salt tectonism dislocated the fine-grained shelf and slope, prevented the development of sedimentary reciprocity at 10–100 kyr time scales, and inhibited fill-and-spill accumulation. We show that only 3% of “lowstand” mass transport deposits can be correlated to low stands in relative sea level, whereas approximately 30% of the deposits are related to transgressions and high stands; the remaining 67% are poorly constrained. Mass transport deposits also show no clear evidence of up-section increases in bypass. Based on our results, we conclude that the dominant control on stratigraphic architecture in offshore Louisiana was not relative sea-level change or patterns of accommodation, but rather differential deposition and concomitant salt-related subsidence, which controlled the distribution of facies, timing and location of mass transport deposits, and rates of sediment accumulation. Our conclusions highlight the importance of sediment supply and local tectonism, and caution against a priori use of conventional sequence stratigraphic and fill-and-spill models to decipher the stratigraphic evolution of actively-deforming mud-dominated continental margins. We therefore recommend treating stratigraphic models as testable hypotheses, rather than as methods of interpretation, particularly in fine-grained areas devoid of well-developed depositional sequences and in settings lacking intraslope ponded-to-perched accumulations.  相似文献   

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