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1.
莱州湾凹陷古近系沙河街组沙三中段发育典型的辫状河三角洲沉积体系。本文基于经典层序地层学理论,通过对莱州湾凹陷三维地震、主要钻井及取心、测井等资料综合分析,对莱州湾凹陷沙三中段层序地层特征及层序格架内沉积体系展布进行精细研究。将沙三中段整体划分为1个三级层序,并根据初次湖泛面、最大湖泛面及高水位体系域域内三角洲期次包络面的界定将沙三中段进一步划分为低水位体系域、湖侵体系域和高水位体系域3个体系域及6个四级层序。在层序格架内分析了研究区沙三中段沉积体系的展布特征及演化规律。沙三中段低水位体系域西部斜坡带发育扇三角洲沉积,北部陡坡带发育近岸水下扇沉积。湖侵体系域发育辫状河三角洲沉积,高水位体系域发育4期辫状河三角洲沉积、高水位体系域Ⅰ、Ⅱ期发育坡移浊积扇沉积。根据层序发育和油气成藏条件分析,认为沙三中段低水位体系域扇三角洲、湖侵体系域辫状河三角洲、高水位体系域坡I和II期的坡移扇沉积成藏条件最为有利,是下一步寻找岩性油气藏的优先目标。  相似文献   

2.
充分利用已有的钻井、测井、录井、地震等资料,应用地震地层学、层序地层学和沉积学理论,对准噶尔盆地东部五彩湾一石树沟地区的中二叠统层序地层进行研究。将中二叠统将军庙组至平地泉组划分为一个层序;又根据不同的沉积组合和几何形状,把将军庙组划分为低水位体系域(LST),平地泉组三段至二段下部划分为湖侵体系域(TST),平地泉组二段下部至一段划分为高水位体系域(HST),凝缩段难以确定。低水位体系域主要为冲积扇、滨浅湖沉积,湖侵体系域为半深湖一深湖、水下扇沉积,高水位体系域为扇三角洲前缘、水下扇沉积。  相似文献   

3.
黄县早第三纪断陷盆地高分辨率层序地层划分   总被引:1,自引:0,他引:1  
详细研究了黄县煤田早第三纪断陷盆地沉积填序列和沉积体系,研究了基准面旋回特点,进行了高分辨率层序地层划分。研究表明,黄县断陷盆地下第三系为1个构造层序,是一个完整的原型断陷盆地沉积充填序列。可划分出2个三级层序,且具有三元结构,即由低水位、水进和高水位体系域组成;层序I低水位体系域由早期和晚期两部分组成,层序Ⅱ高水位体系域亦有早期和晚期两部分构成。主要沉积体系有:扇三角洲体系、湖底扇体系、辫状河三  相似文献   

4.
川西地区上三叠统自下向上可划分为四个陆相层序(层序Ⅰ、Ⅱ、Ⅲ、Ⅳ),每一个层序自下向上都发育有低水位体系域、湖侵体系域和高水位体系域.通过对层序Ⅲ、Ⅳ各体系域的几类岩石地球化学标型参数研究发现,每个层序在沉积的过程中,由低水位体系域到湖侵体系域再到高水位体系域,B含量、Sr/Ba比值、V/Ni比值都经历了从高到低再到高的旋回历程,也即是盆地的湖平面、古气候和古盐度等皆发生了一次旋回性的变化,进一步为层序和体系域的划分提供了证据.  相似文献   

5.
济阳坳陷滩海地区下第三系可划分为3个二级层序,持续时间依次为11.5、9、5.4Ma,3个层序在时空分布上有一定的规律性,总的趋势是沉积中心由南西向北东转移。每个层序可进一步划分出3个株系域;低水位体系域、湖侵体系域及高水位体系域。油气藏的分布规律与层序边界关系密切。  相似文献   

6.
利用沉积学及层序地层学方法,通过对章丘煤田主要构造单元单井沉积相、层序地层分析,将章丘煤田石炭二叠纪含煤岩系的本溪组、太原组、山西组划分为1个一级盆地层序、2个二级构造层序、3个三级层序。在层序内部识别最大湖泛面或与之相当的沉积转换面,划分体系域,并重点对三级层序的划分进行研究。研究认为:三级层序Ⅰ发育高水位体系域和海侵体系域,主要由潮坪沉积体系、障壁-泻湖沉积体系和碳酸盐台地沉积体系组成;层序Ⅱ发育海侵体系域和高水位体系域,主要由潮坪体系、滨外台地体系和障壁-泻湖沉积体系组成;层序Ⅲ中低水位体系域、海侵体系域、高水位体系域都有较好发育,主要由浅水曲流河三角洲沉积体系组成。  相似文献   

7.
结合在陆相盆地中的实例研究,将一个发育完整的陆相三级层序细分为4个体系域:低水位体系域(LST)、水进体系域(TST)、高水位体系域(HST)和水退体系域(RST),称为I型层序。或者一个层序可以不发育低水位体系域,而由水进体系域、高水位体系域和水退体系域组成,称为II型层序。低水位体系域发生在湖平面(基准面)快速下降时期;水进体系域出现在首次湖泛面到最大湖泛面之间;高水位体系域形成在高水位时期的湖平面相对静止期;水退体系域形成在湖平面缓慢下降期,在沉积物供给速率大于可容空间增加速率时形成。一般低水位体系域发育小型进积式准层序组,纵向沉积环境变浅,在盆地边缘形成河流下切作用;水进体系域发育退积式准层序组,沉积环境自下而上明显变深;高水位体系域发育加积型准层序组,纵向沉积环境变化不大,且多为静水沉积;水退体系域发育大型进积式准层序组,沉积环境自下而上明显变浅,沉积体系向盆地中心推进。结合对松辽盆地的实例研究,分别阐述了断陷盆地和坳陷盆地中各不同体系域的油气藏分布规律:低水位体系域主要在断陷盆地的陡坡侧和坳陷盆地的深水区发育透镜状岩性油气藏;水进体系域主要在断陷盆地的陡坡带发育上倾尖灭型岩性油气藏,在缓坡带和坳陷盆地的斜坡带发育地层超覆油气藏;高水位体系域主要以深水区的透镜状岩性油气藏为主;水退体系域在断陷盆地中主要发育地层不整合遮挡油气藏,在坳陷盆地中主要发育断块油气藏以及断层遮挡油气藏。从而,以理论与实践相结合的方式,阐明了陆相层序四分体系域的实用性。  相似文献   

8.
黑龙江东部下白垩统鸡西群层序地层划分与聚煤作用分析   总被引:5,自引:0,他引:5  
依据钻孔及露头资料,对鸡西盆地下白垩统鸡西群层序地层进行了研究,共划分出1个Ⅱ级、3个Ⅲ级层序。Ⅱ级层序代表了鸡西盆地最大一次湖侵→湖退沉积,3个三级层序反映了三次低级别的湖侵→湖退沉积作用。在此基础上讨论了鸡西群的成煤作用特点,其中Ⅱ级层序湖侵背景下的Ⅲ级层序湖侵体系域聚煤作用最好;湖退背景下Ⅲ级层序湖侵体系域聚煤作用次之;低水位背景下Ⅲ级层序湖侵体系域聚煤作用较差,Ⅲ级层序低水位与高水位体系域聚煤作用最差。研究结果对探讨鸡西盆地早白垩世沉积、成煤作用具有重要意义。  相似文献   

9.
利用层序地层学、沉积学原理和方法,对博湖坳陷下侏罗统三工河组进行了层序划分和沉积体系时空配置关系的研究.建立了三工河组的层序地层榕架,将其划分为J1s3、J1s2和JJ1s13个三级层序,其层序和体系域的变化主要受控于凹陷内沉降中心的分布,沉积主要受控于盆地边缘的南缘陡坡带、北缘缓坡带.每个三级层序低水位体系域发育局限,湖扩与高水位体系域发育.沉积体系构成以扇三角洲、湖泊和辫状河三角洲为主.在建立沉积体系时空配置关系的基础上探讨了沉积体系的演化.  相似文献   

10.
苏红图-银根盆地下白垩统层序地层学研究   总被引:2,自引:0,他引:2  
李文厚 《沉积学报》1997,15(3):18-22
本文根据沉积、古生物及地震资料对苏红图-银根盆地下白垩统的层序地层学特征进行了研究。把下白垩统划分为1个三级层序和低水位体系域、湖侵体系域、高水位体系域。根据准层序的叠置方式,准层序组有进积型、退积型和加积型,本区下白垩统可以划分9个准层序组,以退积型准层序组最为发育。苏红图-银根盆地早白垩世早期沉积格局曾发生过显著变化,从早到晚先后发育冲积扇、扇三角洲、浅湖和深湖相沉积,并在深湖相暗色页岩中夹有浊流和泥石流沉积,为退积型湖进层序。早白垩世晚期则由滨浅湖相演化为滨湖沼泽和河流相沉积,为进积型湖退层序。本区的湖侵体系域浅湖-深湖相暗色泥、页岩厚度大,有机质丰度高,类型好,是重要的烃源岩。低水位体系域的扇三角洲层序以加积型为特征,即下部为扇三角洲平原,中部为扇三角洲前缘,上部为前扇三角洲。反映了该区处于活动盆地边缘,湖水由浅变深,扇三角洲相应后退,沉降速率大于沉积速率。其中扇三角洲前缘砂体的储集作用不可低估。高水位体系域的滨浅湖滩砂也是重要的油气储集体。而湖侵体系域的深湖相泥、页岩和高水位体系域的滨湖沼泽相泥岩均可作为区域盖层。它们在垂向上构成了有利的生储盖组合。  相似文献   

11.
根据山东惠民盆地中央隆起带古近系沙河街组第三段层序地层学研究,根据层序中湖平面变化特点和相应的沉积物特征,提出了陆相湖盆中层序内体系域的四分法,一个完整的层序由低位、湖侵、高位和下降四个体系域组成,并且层序界面位于湖平面最大下降的位置,介于下降域和低位域之间。层序地层中存在四个关键性界面:首泛面、最大湖泛面、始降面和最大下降面,其中首泛面对应于湖水由相对稳定到快速上升时的初始湖泛面,为低位域与湖侵域间的分界面;最大湖泛面对应于湖水快速上涨至最大限度时的湖泛面,为湖侵域与高位域间的分界面,在界面附近多形成特征的CS段;始降面对应于湖平面开始快速下降时的沉积界面,为高位域与下降域的分界面;最大下降面也是层序界面,为湖盆水体快速下降或湖盆岸线快速退到最低点时的沉积界面。结合研究区的岩芯、录井、测井、地震等资料综合分析,本文总结了四个关键面的识别标志。中央隆起带沙三段沉积共划分出六个体系域,分属三个层序。本文以层序II沉积为例,阐述了不同体系域的沉积体系特征,低位期湖盆水域面积小,河流-三角洲沉积体系发育,河流流经距离长,边缘地区形成似下切谷沉积;湖侵期发育小规模的退积式三角洲沉积,砂体较不发育;高位期湖盆水域面积大,砂体以深水浊积砂体为特征;下降期多发育进积式砂体,砂体发育。因此,位于层序界面之下的下降域和之上的低位域是湖盆砂体有利发育期,湖侵域和高位域是生油岩主要形成时期。  相似文献   

12.
Gas-bearing deposits in the Lower Mingyuefeng Formation of Paleogene, Lishui Sag, East China Sea Shelf Basin consist of shoreface sandstones of the highstand systems tract (HST) and transgressive systems tract (TST), and deltaic sandstones of the lowstand systems tract (LST) and falling stage systems tract (FSST). Detailed petrographic observations suggest that the diagenetic features and related evolution of these deposits cannot be simply characterized and demonstrated in the depth domain. However, the occurrence of diagenetic minerals systematically depends on the studied interval within the HST, TST, LST, and FSST; therefore, diagenesis in this region can be better constrained when studied in the context of the depositional environments and sequence stratigraphic framework. The eogenetic processes in such settings include: (1) microcrystalline siderite precipitated as concretions in almost all environments and systems tracts, which inhibited further mechanical compaction; (2) grain dissolution and kaolinitization occurred in shoreface HST sandstones and deltaic LST and FSST sandstones; (3) glaucony was locally observed, which did not clearly reflect the controls of facies or sequence stratigraphy; and (4) cementation by pyrite aggregates occurred in the shoreface HST sandstones and deltaic LST sandstones. The mesogenetic diagenesis includes: (1) partial conversion of kaolinite into dickite in deltaic LST sandstones, and minor chlorite cementation in deltaic FSST sandstones; (2) transformation of kaolinite into illite and quartz cementation in deltaic LST and FSST sandstones; (3) frequent precipitation of ankerite and ferroan calcite in shoreface TST sandstones and early HST sandstones, forming baffles and barriers for fluid flow, with common calcite in shoreface HST sandstones as a late diagenetic cement; and (4) formation of dawsonite in the deltaic LST and FSST sandstones, which is interpreted to be a product of the invasion of a CO2-rich fluid, and acts as a good indicator of CO2-bearing reservoirs. This study has thus constructed a reliable conceptual model to describe the spatial and temporal distribution of diagenetic alterations. The results may provide an entirely new conceptual framework and methodology for successful gas exploration in the continental margins of offshore China, thus allowing us to predict and unravel the distribution and quality evolution of clastic reservoirs at a more detailed and reliable scale.  相似文献   

13.
中部4区块位于准噶尔盆地腹部的昌吉凹陷,侏罗纪时堆积了浅水辫状三角洲相粗粒砂砾岩与深水湖泊相泥岩沉积,这些沉积在D2井区显示出多个明显的旋回.根据沉积相序变化、准层序叠加样式、测井曲线特征,通过伴生的低水位域底界面的识别及附近的超失、削截特征分析,仔细追踪和查明了10条关键层序界面,划分出9个三级层序,识别出低水位、湖进和高水位体系域.由于处于关键坡折带的下倾方向,每个层序均具有完整的三分结构,年限平均约5Ma,共识别出27个体系域,准层序组62个,准层序148个.单个层序厚度平均209.3m,单个准层序组平均厚30.4m,单个准层序平均厚13.0m.  相似文献   

14.
利用上超点法重建渤海湾盆地辽中凹陷渐新世湖平面变化   总被引:1,自引:0,他引:1  
标准层序是指同时包含高位体系域HST、湖侵体系域TST、下降体系域FSST和低位体系域LST的三级层序。通过对标准三级层序各类体系域中上超特征的分析,将一个标准层序的上超点分为5大类,即LST上超点、TST上超点、早期HST上超点、晚期HST上超点和FSST上超点,提出了通过统计层序内各类上超点来反演湖平面变化史的方法...  相似文献   

15.
扬子地台西缘志留纪层序地层研究   总被引:1,自引:0,他引:1  
应用层序地层学的原理和方法,对扬子地台西缘陕西宁强-四川广元地区的志留系剖面进行了重新研究,识别出9个三级层序。三级层序均发育TST和HST,而缺乏LST和SMST。通过区内沉积层序的对比,建立了扬子西缘专留纪层序地层格架。最后探讨了该区馨留纪的海平面变化规律。  相似文献   

16.
The spatial and temporal distribution of diagenetic alterations has been constrained in relationship to depositional facies and sequence stratigraphy of the Upper Ordovician glaciogenic quartzarenite sandstones in the Murzuq Basin, SW Libya, which were deposited during the Haritanian glaciation when the basin was laying along the continental margin of Gondwana. Eogenetic alterations encountered include: (i) replacement of detrital silicates, mud matrix and pseudomatrix by kaolinite in paraglacial, tide-dominated deltaic, in foreshore to shoreface (highstand systems tract; HST) and in post-glacial, Gilbert-type deltaic (lowstand systems tract; LST) sandstones, particularly below the sequence boundaries (SB). Kaolinite formation is attributed to the influx of meteoric water during relative sea level fall and basinward shift of the shoreline. (ii) Cementation by calcite (δ18OVPDB = − 3.1‰ to + 1.1‰ and δ13CVPDB = + 1.7‰ to + 3.5‰) and Mg-rich siderite in the paraglacial, tide-dominated deltaic and foreshore to shoreface HST sandstones, in the glacial, tide-dominated estuarine (transgressive systems tract; TST) sandstones and in the post-glacial, shoreface TST sandstones is interpreted to have occurred from marine pore-waters. (iii) Cementation by Mg-poor siderite, which occurs in the post-glacial, Gilbert-type deltaic LST sandstones and in the paraglacial, tide-dominated deltaic and foreshore to shoreface HST sandstones, is interpreted to have occurred from meteoric waters during relative sea level fall and basinward shift of the shoreline. (iv) Pervasive cementation by iron oxides has occurred in the glacial, shoreface–offshore TST sandstones and post-glacial, shoreface TST sandstones immediately below the maximum flooding surfaces (MFS), which was presumably enhanced by prolonged residence time of the sediments under oxic diagenetic conditions at the seafloor. (v) Formation of grain-coating infiltrated clays mainly in the glacial, fluvial incised-valley LST sandstones and in the post-glacial, Gilbert-type deltaic LST sandstones as well as, less commonly, in the paraglacial, foreshore to shoreface HST sandstones and in the tide-dominated deltaic HST sandstones below the SBs.

Mesogenetic alterations include mainly the formation of abundant quartz overgrowths in the glacial, fluvial incised-valley LST sandstones, post-glacial, Gilbert-type deltaic LST sandstones and glacial, shoreface TST sandstones, in which early carbonate cements are lacking. Illite, chlorite and albitized feldspars, which occur in small amounts, are most common in the glacial, tide-dominated estuarine TST sandstones and paraglacial, shoreface HST sandstones. This study demonstrates that the spatial and temporal distribution of diagenetic alterations and their impact on reservoir-quality evolution in glacial, paraglacial and post-glacial sandstones can be better elucidated when linked to the depositional facies and sequence stratigraphic framework.  相似文献   


17.
在论述马家沟组三级层序地层成因的基础上,重新厘定了鄂尔多斯盆地马家沟组层序地层格架。马家沟组马一段至马五段划分为4个三级层序,除了Sq1为Ⅰ型层序之外,Sq2、Sq3、Sq4都是Ⅱ型层序。在陆架内Sq1和Sq4由TST和HST构成;Sq2、Sq3由TST、HST和ISLST构成。TST以正常盐度浅海中形成的生物灰岩和泥晶灰岩为特征,HST以准同生期近地表的略为咸化海水成因的泥晶—细粉晶白云岩为特征,陆架内低水位体系域(ISLST)由陆架内盐湖形成的巨厚的蒸发岩系构成。ISLST和HST在空间分布上和成因上是密切相关的,ISLST置于Ⅱ型层序的顶部或者近顶部比较合理。传统的层序地层学将层序界面置于高水位体系域与低水位体系域之间,在此建议将层序界面置于低水位体系域与海侵体系域之间的海侵面。编制了层序3的海侵体系域、高水位体系域、低水位体系域全盆地层序古地理略图。  相似文献   

18.
The early stage of Sichuan Basin formation was controlled by the convergence of three major Chinese continental blocks during the Indosinian orogeny that include South China,North China,and Qiangtang blocks.Although the Late Triassic Xujiahe Formation is assumed to represent the commencement of continental deposition in the Sichuan Basin,little research is available on the details of this particular stratum.Sequence stratigraphic analysis reveals that the Xujiahe Formation comprises four third-order depositional sequences.Moreover,two tectono-sedimentary evolution stages,deposition and denudation,have been identified.Typical wedge-shaped geometry revealed in a cross section of the southern Sichuan Basin normal to the Longmen Shan fold-thrust belt is displayed for the entire Xujiahe Formation.The depositional extent did not cover the Luzhou paleohigh during the LST1 to LST2 (LST,TST and HST mean Iowstand,transgressive and highstand systems tracts,1,2,3 and 4 represent depositional sequence 1,2,3 and 4),deltaic and fluvial systems fed sediments from the Longmen Shan belt,Luzhou paleohigh,Hannan dome,and Daba Shan paleohigh into a foreland basin with a centrally located lake.The forebulge of the western Sichuan foreland basin was located southeast of the Luzhou paleohigh after LST2.According to the principle of nonmarine sequence stratigraphy and the lithology of the Xujiahe Formation,four thrusting events in the Longmen Shan fold-thrust belt were distinguished,corresponding to the basal boundaries of sequences 1,2,3,and 4.The northern Sichuan Basin was tilted after the deposition of sequence 3,inducing intensive erosion of sequences 3 and 4,and formation of wedge-shaped deposition geometry in sequence 4 from south to north.The tilting probably resulted from small-scale subduction and exhumation of the western South China block during the South and North China block collision.  相似文献   

19.
辽河盆地东部凹陷北段复式断陷层序地层与油气   总被引:3,自引:5,他引:3       下载免费PDF全文
刘立  付荣 《古地理学报》2001,3(1):71-77
辽河盆地为中国东部大陆裂谷渤海湾裂谷系的北延部分,是中、新生代发育起来的断陷盆地。 东部凹陷北段是辽河盆地的一部分,也有人将其称为裂谷段,具典型的裂谷盆地的发育特征。经过多条横切构造走向的剖面研究,证实了东部凹陷北段为复式断陷,断陷的走向与盆地走向基本平行。所谓的复式断陷为两个或两个以上的半地堑以某种方式组合而成,在一定时期内,相邻的次一级半地堑各有独立的沉积物供给系统,但当各个次级半地堑充填满以后,相邻的次级地堑具有统一的物源供给系统和水系联通特征,以较大的整体断陷形式继续发育。在控盆断裂一侧的断陷内层序发育较全,而斜坡及边缘地带层序发育不完全,通常缺失低水位体系域或水退体系域。复式断陷不同断陷内的层序,主要受旋回内不同级别幕式构造运动和气候周期性变化的控制,两者的共同作用影响着湖平面的升降和可容空间的变化。由于相邻断陷对物源侵入的阻挡作用,在一定的时期内,各断陷发育独立沉积体系和构造部位的差异,导致了层序地层格架内生储盖层及其组合的发育差异。厚度最大的密集段发育在TST与HST之间,是区域性的生油岩; LST,TST底部,HST顶部、RST通常构成有利储层;密集段也通常成为较好的盖层。在上述因素的作用下,东部凹陷北段复式断陷湖盆中的油气,主要富集在有利构造岩相带的水退体系域、水进体系域和低水位体系域中。层序地层格架内油气藏类型及发育规模存在一定的规律:在缓坡一侧的断陷内,易形成地层超覆型油气藏、地层不整合遮挡油气藏;在陡坡一侧的断陷内,易形成透镜状油气藏、背斜油气藏,起决定作用的是生储盖层的发育状况及其与有利的构造圈闭条件的配置关系。  相似文献   

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