藏北羌塘盆地中部中侏罗统层序地层研究

运用露头层序地层学原理与方法,将羌塘盆地中部地区中侏罗统划分为6个Ⅱ型层序,并阐述了各层序的体系域特征和形成的沉积动力学机制以及海平面变化对沉积、生物迁移及环境的控制作用。研究区中侏罗统存在6个海平面变化旋回:巴柔期早期、巴柔期晚期、巴通期早期、巴通期晚期、卡洛期早期和卡洛期晚期。研究结果表明,研究区中侏罗世为一裂陷—坳陷盆地,海平面变化与全球海平面变化的曲线基本吻合,其沉积面貌主要受控于全球海平面变化。     

特提斯-喜马拉雅北带侏罗纪——白垩纪界线层序地层分析

侏罗纪、白垩纪是特提斯-喜马拉雅海区演化过程中的一个极其重要的阶段,其沉积物蕴涵着新特提斯早期演变的丰富信息。通过实测浪卡子县多久乡卡东晚侏罗世—早白垩世地层剖面,结合前人的研究成果,在对剖面进行层序地层分析的基础上,识别出4个三级层序。特提斯-喜马拉雅海区晚侏罗世层序地层总体上表现为海退的进积序列,反映了特提斯-喜马拉雅海区持续收缩和海平面下降的过程;早白垩世层序地层总体表现为海进的退积序列,反映了特提斯洋壳的扩张阶段。早白垩世桑秀组可以分为2个层序,第一个层序为Ⅰ型层序,镜下观察表明,早白垩世桑秀组底部的砂岩为近源沉积,属滨浅海相沉积,为低水位体系域,颗粒的定向性指示该区后期受到强烈的挤压作用;中部为次深海沉积,为海侵和高水位体系域;第二个层序为Ⅱ型层序,发育陆棚边缘体系域、海侵体系域和高位体系域,由陆棚、火山陆隆和浊流沉积组成。甲不拉组的砾岩属于新层序的开始,为低水位体系域。该剖面海平面相对变化曲线与同期全球海平面相对变化曲线基本一致。该区层序形成的控制因素包括构造沉降-火山活动、海平面相对变化和沉积物供应。结合锆石SHR IM P年代学研究可以确定侏罗纪/白垩纪的界线位于前人认为的维美组上部砂岩之底。     

雪峰古陆边缘上石炭统露头层序地层

雪峰古陆边缘沅陵地区的上石炭统岩性特殊,以灰岩为主平白云质灰岩、砾屑灰岩与砾岩、砂岩相互成层,交替出现,因此,相对海平面升降变化在这种类型沉积中表现明显,利用层序地层的研究。上石炭统为１个三级层序,底部以Ｉ型层序与震旦系留茶坡组硅质岩接触;顶部仍以Ｉ型层序边界与下二叠统黔阳组成邻。包括低水位体系域、海进体系域和高水位体系域;依据准层序的叠是分为两个准层序组,即海进体系域和高水位体系域。     

塔里木盆地巴楚—麦盖提地区石炭系混合沉积研究*

通过岩心、薄片观察,从岩石学特征入手,结合测井资料,对塔里木盆地巴楚—麦盖提地区石炭系的陆源碎屑—碳酸盐混积岩和混积层系进行了研究。根据混积强度将混积岩划分为混积型碎屑岩、混积型碳酸盐岩和高度混积岩。巴楚组下泥岩段和中泥岩段发育混积型碎屑岩,巴楚组生屑灰岩段、中泥岩段和小海子组发育混积型碳酸盐岩,卡拉沙依组上泥岩段、巴楚组下泥岩段及巴什托局部地区的中泥岩段发育高度混积岩。高度混积岩出现在海退期沉积的碎屑岩段,代表了陆源碎屑—碳酸盐强烈混合的过渡性沉积环境。研究区石炭系可识别出4个三级层序,混积层系主要发育在海侵体系域早期和高位体系域晚期,以间断混合和相缘混合为主。研究认为混积强度是评价混合沉积环境性质的主要参数,并将其划分为4级。下泥岩段存在混积强度达3级以上的混积界面,能用于地层对比。最后,结合混合沉积特征讨论了构造运动和海平面变化对研究区石炭系层序组以上的混合沉积的控制作用。     

鄂尔多斯陆表海层序地层中的低位域沉积——以太原组上段桥头砂岩为例

鄂尔多斯缓坡型陆表海的层序构成通常以海侵和高位体系域为主 ,低位体系域发育在古大陆边缘或缺失。以太原组上部灰岩段中桥头砂岩为例 ,通过对露头、岩心、测井曲线的分析和层序对比以及海平面升降变化对研究区沉积影响的分析 ,认为桥头砂岩形成于不同的三级层序内 ,由 3套低位域下切河谷充填沉积叠置而成 ,说明在盆地内古大陆架上也可以发育低位体系域沉积。桥头砂岩形成于相对海平面下降时期 ,桥 3砂岩在相对海平面上升之后发展为潮河道继续存在。鄂尔多斯深盆气的成藏特点使具有微裂隙和溶蚀孔隙的桥头砂岩具有深盆气勘探和开发的前景。     

相对海平面变化与南海珠江深水扇系统的响应

根据微体古生物分析建立起来的珠江口盆地第三系相对海平面曲线,具有与全球海平面变化相一致的三级旋回和不一致的二级旋回。三级海平面升降导致了各沉积层序体系域在宽广陆架和陆坡之间的迁移,研究证实,位于南中国海北缘、珠江口外的陆坡深水区广泛发育第三系多层序叠置的南海珠江深水扇系统。区域性构造作用使得珠江口盆地二级海平面变化与全球海平面变化具有不一致性,并形成与全球海退趋势相反的海侵型海平面曲线。受相对海平面变化的控制,现今处于陆坡深水区的白云凹陷自32Ma南海扩张以来经历了三台阶式的海侵事件,形成了台阶式退积层序组合,具有下粗上细的沉积序列;造就了23.8Ma以前的浅水三角洲-滨岸砂泥岩沉积组合;23.8~10.5Ma的深水扇砂泥岩为主的沉积组合;以及10.5Ma以来主要为远端的细粒沉积为主。     

川滇黔桂地区二叠纪不同成因盆地层序地层模型

通过不同类型沉积盆地层序界面性质、层序类型、结构、组成、完整性、对称性以及层序发育特征和控制因素研究表明,不同成因沉积盆地,其层序内部构型及成因格架各异.克拉通盆地层序发育主要受全球海平面变化及碳酸盐自旋回控制,LST以陆上暴露不整合面及其上风化残积相为特征,TST以海侵上超不整合面上相对薄的超覆型退积准层序组为特色,HST表现为厚层加-进积丘礁滩组合;对于被动陆缘裂谷盆地,主控因素包括全球海平面变化和同沉积断裂活动,LST期,孤台以陆上暴露不整合面及残积相为标志,台盆表现为水下间断不整合面及上覆混屑浊积岩,TST以台盆硅灰岩-硅岩退积准层序组不断向斜坡和孤台上超为特征,HST期,孤台以加积-进积丘礁滩组合为主,台盆为加积型钙屑重力流沉积,弧后裂谷盆地层序特征与被动陆缘裂谷盆地相似,但其台盆加深加宽,层序以硅质岩及火山碎屑浊积岩为主,揭示层序发育主要受同沉积断裂活动、全球海平面变化及火山活动控制;被动陆缘走滑盆地层序发育主要受控于不同沉积断裂活动及全球海平面变化,层序组成以放射虫硅质岩和深水泥岩为主;前陆盆地LST以造山侵蚀不整合面及盆底扇沉积为特征,TST表现为巨厚层浊积扇-扇三角洲弱进积-弱退积充填型准?     

塔里木盆地塔河地区石炭系卡拉沙依组层序格架内沉积模式北大核心CSCD

近些年来,塔里木盆地塔河地区石炭系卡拉沙依组碎屑岩的油气勘探取得了丰硕成果。依据全球海平面变化,结合钻井和地震资料,本文划分了塔河地区石炭系卡拉沙依组层序,并提出其层序格架内的三种体系域沉积模式。塔河地区石炭系卡拉沙依组碎屑岩地层处于一个二级层序之内,其内部砂泥岩段被划分为5个三级层序。本文总结了每个层序界面、层序的内部特征及层序发育的控制因素,提出了塔河地区石炭系卡拉沙依组三级层序内的低位、海侵和高位3种体系域沉积模式,并分析了其内部沉积特征。塔河地区石炭系卡拉沙依组碎屑岩地层沉积物源为塔北剥蚀区,主要发育辫状河三角洲-陆棚沉积体系,其中上泥岩段整体主要发育浅海陆棚沉积,砂泥岩段(SQC1-2k^(5)—SQC1-2k^(1))海侵体系域主要发育退积型前三角洲,高位体系域主要发育进积型辫状河三角洲平原-三角洲前缘-前三角洲;低位体系域发育期主要作用于前一个三级层序的高位体系域,为三级层序界面形成期。构造运动、海平面升降、物源供给及古气候是塔河地区石炭系卡拉沙依组三级层序及其内部体系域发育的主要控制因素。     

济阳坳陷下第三系湖相沉积的层序地层学分析

本文按照层序地层学原理,应用多种资料,分析了济阳坳陷地震T2,T6际准层的层序地层学意义,将济阳坳陷下第三系划分成3个二级层序,其中又可以划分出多个三级层序。每个二级层序都可以分成3个体系域:低水位体系域（LST）以盐（膏）岩或灰色泥岩,碳酸盐岩沉积为主;水进体系域（TST）以大套暗色泥岩沉积为特征;高水位体系域（HST）对应于河流 三角洲沉积。湖水面升降与构造运动,古气候及全球性海平面变化有关。3次大的水进期形成的暗色泥岩是主要生油层。低水位近岸（水下）扇、斜坡碳酸盐岩、与三角洲有关的各类砂体是良好的油气储层。层序地层学原理可以应用于湖相沉积。     

苏红图-银根盆地下白垩统层序地层学研究

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。     

准噶尔盆地中部2区块高分辨层序地层研究

根据沉积相序变化、准层序叠加样式、测井曲线特征,运用关键坡折带知识,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,仔细追踪和查明了准噶尔盆地腹部地区中部2区块9条关键界面.进行了侏罗系的高分辨层序地层的划分。研究表明C1井区J_1b_2-J_2t沉积时期可划分出8个三级层序,均具有完整的三分结构:LST、TST和HST;共划分出27个体系域,共识别出准层序组56个,准层序118个。单个层序的厚度105.6～176.8 m,平均140.7 m;单个准层序组平均24.9 m;单个准层序平均11.8 m。     

东胜煤田含煤岩系层序地层特征与聚煤规律分析——以东胜煤田阿不亥煤炭勘查区为例

研究区含煤岩系主要为侏罗系中统延安组,通过煤岩层研究和对比,认为延安组本身为一个完整的层序,可分为三个体系域、五个小层序组和18个小层序;体系域、小层序组和小层序之间的转换面是聚煤的主要层位。含煤地层可编号18层煤,其中可采煤层15层,根据层序地层分析和含煤岩系沉积特点,将含煤地层分为三个岩性段,5个煤组,相对应三个聚煤期和5个成因单元。该区的聚煤作用主要受到沉积环境、古地形和古构造的控制。     

Facies and sequence stratigraphic analysis in an intracratonic, thermal-relaxation basin: the Early Proterozoic, Lower Quilalar Formation and Ballara Quartzite, Mount Isa Inlier, Australia

The Quilalar Formation and correlative Mary Kathleen Group in the Mount Isa Inlier, Australia, conformably overlie rift-related volcanics and sediments and non-conformably overlie basement rocks. They represent a thermal-relaxation phase of sedimentation between 1780 and 1740 Ma. Facies analysis of the lower siliciclastic member of the Quilalar Formation and the coeval Ballara Quartzite permits discrimination of depositional systems that were restricted areally to either N-S-trending marginal platform or central trough palaeogeographic settings. Four depositional systems, each consisting of several facies, are represented in the lower Quilalar Formation-Ballara Quartzite; these are categorized broadly as storm-dominated shelf (SDS), continental (C), tide-dominated shelf (TDS) and wave-dominated shoreline (WDS). SDS facies consist either of black pyritic mudstone intervals up to 10 m thick, or mudstone and sandstone associated in 6–12-m-thick, coarsening-upward parasequences. Black mudstones are interpreted as condensed sections that developed as a result of slow sedimentation in an outer-shelf setting starved of siliciclastic influx. Vertical transition of facies in parasequences reflects flooding followed by shoaling of different shelf subenvironments; the shoreface contains evidence of subaerial exposure. Continental facies consist of fining-upward parasequences of fluvial origin and tabular, 0·4–4-m-thick, aeolian parasequences. TDS facies are represented by stacked, tabular parasequences between 0·5 and 5 m thick. Vertical arrangement of facies in parasequences reflects flooding and establishment of a tidal shelf followed by shoaling to intertidal conditions. WDS facies are preserved in 0·5–3-m-thick, stacked, tabular parasequences. Vertical transition of facies reflects initial flooding with wave reworking of underlying arenites along a ravinement surface, followed by shoaling from lower shoreface to foreshore conditions. Parasequences are stacked in retrogradational and progradational parasequence sets. Retrogradational sets consist of thin SDS parasequences in the trough, and C, TDS and probably WDS parasequences on the platforms. Thick SDS parasequences in the trough, and TDS, subordinate C and probably WDS parasequences on the platforms make up progradational parasequence sets. Depositional systems are associated in systems tracts that make up 40–140-m-thick sequences bounded by type-2 sequence boundaries that are disconformities. Transgressive systems tracts consist of C, TDS and probably WDS depositional systems on the platforms and the SDS depositional system and suspension mudstone deposits in the trough. The transgressive systems tract is characterized by retrogradational parasequence sets and developed in response to accelerating rates of sea-level rise following lowstand. Condensed-section deposits in the trough, and the thickest TDS parasequences on the platforms reflect maximum rates of sea-level rise and define maximum flooding surfaces. Highstand systems tract deposits are progradational. Early highstand systems tracts are represented by TDS and probably WDS depositional systems on the platforms and suspension mudstone deposits in the trough and reflect decreasing rates of sea-level rise. Later highstand systems tracts consist of the progradational SDS depositional system in the trough and, possibly, thin continental facies on the platforms. This stage of sequence development is related to slow rates of sea-level rise, stillstand and slow rates of fall. Lowstand deposits of shelf-margin systems tracts are not recognized but may be represented by shoreface deposits at the top of progradational SDS parasequence sets.     

高分辨露头层序地层学的研究基础──准层序的识别

以塔里木盆地西南缘下石炭统和什拉甫组为例，将微相分析及古生态分析应用于准层序研究之中。在此基础之上，分析沉积层序及其内部各体系域、各种界面的沉积特征。同时，根据准层序垂直叠加的特征来寻找沉积层序内部更高级次的旋回，以达到提高沉积层序的分辨率之目的，恢复该地区维宪期多级次古海平面变化特征。强调准层序分析是高分辨露头层序地层学的研究基础。     

基于沉积微相的野外露头剖面准层序分析——以鄂尔多斯盆地奥陶系临汾晋王坟剖面马家沟组为例

鄂尔多斯盆地奥陶系为广泛的陆表海碳酸盐岩沉积,其东部马家沟组岩相特征、岩石组合类型和旋回性丰富多样。通过对本区临汾晋王坟剖面的奥陶系马家沟组地层进行精细测量,笔者从剖面的沉积特征入手,进行沉积环境和沉积微相的分析,并以沉积微相的纵向演变规律为基础,结合准层序向上变浅的本质特征,识别划分野外露头剖面的准层序。研究区马家沟组共识别出32个准层序,可分为两种类型:准层序类型Ⅰ跨越若干微环境,相变向上为浅;准层序类型Ⅱ沉积于同一个微环境,向上有层厚的渐变趋势。两种类型准层序的形成取决于沉积物供给、短周期海平面升降和地层沉降三者之间的关系和相互作用。研究区内的准层序类型Ⅰ发育广泛,较为常见,类型Ⅱ则发育较少。     

黔桂泥盆纪层序地层及海平面变化的频幅、速度和相位

通过对广西六景、贵州独山和乌当泥盆系剖面层序、体系域、副层序及作用相和环境相的系统研究,识别出2种层序界面;3种海进过程和10种层序、体系域和相对海面变化.并发现,阶跃型高幅海平面变化形成的层序界面、层序、体系域、副层序和旋回层往往可在大区域追踪对比;剖面作用相、环境相分析是露头层序地层和相对海平面变化研究的基础,剖面上层序、体系域及其反映的相对海平面变化的频率、幅度、速度和相位研究对层序界面、层序、体系域、副层序和旋回层的空间延拓、等时追踪对比和驱动机制的成因解释有重要的指导、预测作用.     

鄂尔多斯盆地中部马五1亚段高分辨率层序地层格架中风化成岩模式和储层特征

以层序地层学理论为指导,研究了鄂尔多斯盆地中部奥陶系风化壳储层的层序地层特征,建立了马五₁亚段的高分辨率层序地层格架,在其内识别出了4个准层序;通过建立海平面变化与风化成岩（ 岩溶） 作用的关系模式,从成因上阐明了层间岩溶和后期高级别的风化成岩（ 岩熔） 作用的发生过程和控制因素,揭示了在碳酸盐岩高分辨率层序地层格架中,不同级别的海平面变化周期控制着不同级别的沉积层序和风化成岩（ 岩溶） 作用;分析了准层序与储层物性的关系,认为在鄂尔多斯盆地中部奥陶系风化壳储层中,准层序界面控制着层间岩溶的发育,是影响马五₁亚段风化壳储层性质的主要因素。     

Evolution of an ancient (Lower Cretaceous) marginal‐marine system from tide‐dominated to wave‐dominated deposition,McMurray Formation

Regionally extensive parasequences in the upper McMurray Formation, Grouse Paleovalley, north‐east Alberta, Canada, preserve a shift in depositional processes in a paralic environment from tide domination, with notable fluvial influence, through to wave domination. Three stacked parasequences form the upper McMurray Formation and are separated by allogenic flooding surfaces. Sediments within the three parasequences are grouped into three facies associations: wave‐dominated/storm‐dominated deltas, storm‐affected shorefaces to sheltered bay‐margin and fluvio‐tidal brackish‐water channels. The two oldest parasequences comprise dominantly tide‐dominated, wave‐influenced/fluvial‐influenced, shoreface to bay‐margin deposits bisected by penecontemporaneous brackish‐water channels. Brackish‐water channels trend approximately north‐west/south‐east, which is perpendicular to the interpreted shoreline trend; this implies that the basinward and progradational direction was towards the north‐west during deposition of the upper McMurray Formation in Grouse Paleovalley. The youngest parasequence is interpreted as amalgamated wave‐dominated/storm‐dominated delta lobes. The transition from tide‐dominated deposition in the oldest two parasequences to wave‐dominated deposition in the youngest is attributed mainly to drowning of carbonate highlands to the north and north‐west of the study area, and potentially to relative changes in accommodation space and deposition rate. The sedimentological, ichnological and regional distribution of the three facies associations within each parasequence are compared to modern and Holocene analogues that have experienced similar shifts in process dominance. Through this comparison it is possible to consider how shifts in depositional processes are expressed in the rock record. In particular, this study provides one of few ancient examples of preservation of depositional process shifts and showcases how topography impacts the character and architecture of marginal‐marine systems.     

Application of sequence stratigraphic concepts to the Upper Cretaceous Tununk Shale Member of the Mancos Shale Formation,south-central Utah: Parasequence styles in shelfal mudstone strata

Although sequence stratigraphic concepts have been applied extensively to coarse-grained siliciclastic deposits in nearshore environments, high-resolution sequence stratigraphic analysis has not been widely applied to mudstone-dominated sedimentary successions deposited in more distal hemipelagic to pelagic settings. To examine how sequence stratigraphic frameworks can be derived from the facies variability of mudstone-dominated successions, the Tununk Shale Member of the Mancos Shale Formation in south-central Utah (USA) was examined in detail through a combination of sedimentological, stratigraphic and petrographic methods. The Tununk Shale accumulated on a storm-dominated shelf during the second-order Greenhorn sea-level cycle. During this eustatic event, the depositional environment of the Tununk Shale shifted laterally from distal middle shelf to outer shelf, then from an outer shelf to an inner shelf environment. At least 49 parasequences can be identified within the Tununk Shale. Each parasequence shows a coarsening-upward trend via upward increases in silt and sand content, thickness and lateral continuity of laminae/beds, and abundance of storm-generated sedimentary structures. Variations in bioturbation styles within parasequences are complex, although abrupt changes in bioturbation intensity or diversity commonly occur across parasequence boundaries (i.e. flooding surfaces). Due to changes in depositional environments, dominant sediment supply and bioturbation characteristics, parasequence styles in the Tununk Shale show considerable variability. Based on parasequence stacking patterns, eleven system tracts, four depositional sequences and key sequence stratigraphic surfaces can be identified. The high-resolution sequence stratigraphic framework of the Tununk Shale reveals a hierarchy of stratal cyclicity. Application of sequence stratigraphic concepts to this thick mudstone-dominated succession provides important insights into the underlying causes of heterogeneity in these rocks over multiple thickness scales (millimetre-scale to metre-scale). The detailed sedimentological characterization of parasequences, system tracts and depositional sequences in the Tununk Shale provides conceptual approaches that can aid the development of high-resolution sequence stratigraphic frameworks in other ancient shelf mudstone successions.     

湘西王村剖面寒武系花桥组浊积岩特征及其大地构造意义

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,花桥组中浊流沉积发育,可识别出7次规模较大的浊流活动期,第一期浊积岩包括69个浊积序列,分别归属于11个副层序;第二期浊积岩包括37个浊积序列,分别归属于7个副层序。每个副层序的下部表现为近源浊积岩,上部表现为远源浊积岩,所代表的海水深度变化由浅变深。第一期浊流活动发生在海平面上升时期,形成三级层序的海侵体系域;第二期浊流活动发生在海平面较低、斜坡较陡时期,形成三级层序的低水位体系域。江南斜坡带中—上寒武世浊积岩频繁出现反映台地边缘深大断裂周期性活动强,断裂两盘升降差异运动显著。