塔里木盆地塔中地区志留系柯坪塔格组沉积相与沉积模式

塔中地区志留系自下而上包括柯坪塔格组(下沥青砂岩段、灰色泥岩段、上沥青砂岩段)、塔塔埃尔塔格组（红色泥岩段和砂泥岩段）、依木干他乌组。通过对塔中地区志留系钻井岩心观察和盆地西北部阿克苏、柯坪、巴楚等地露头剖面的观察,塔中地区志留系下沥青砂岩段岩石类型主要为绿灰色泥岩、粉砂质泥岩、泥质粉砂岩、粉砂岩、极细砂岩和细砂岩,部分井发育中细砂岩和中砂岩,砂岩层中常见大量撕裂状泥砾和黄铁矿,发育水平纹理、平行层理、低角度交错层理和楔状交错层理,在露头剖面中可见槽状交错层理。发育的主要沉积相类型为前滨-临滨、浅海陆棚、受风暴影响的浅海砂坝或潮汐砂脊等。在部分井的志留系底部还可见砂砾岩沉积,砾石磨圆较好,砾石成分为石英岩、燧石、泥砾、砂岩砾及其它变质岩砾,向上过渡为中粗砂岩和中细砂岩,发育板状和槽状交错层理,具向上变细的粒序结构,具河流相沉积特征,如塔中30、塔中161井的志留系底部。总体认为塔中地区志留系柯坪塔格组下沥青砂岩段为无障壁滨线-陆棚为主的沉积体系,具有海侵背景下受风暴控制的滨线－陆棚沉积模式, 随海侵发展形成宽度几十公里以上的滨线－陆棚砂岩沉积体,垂向上为滨岸砂到陆棚砂的演化序列。上沥青砂岩段以潮坪沉积为主,并有部分前滨和临滨沉积,横向相变,垂向交互叠置,在砂体发育程度和规模上较下沥青砂岩段差。根据岩心物性和测井物性分析,浅海陆棚沙坝和滨岸沙坝砂岩储集性好于潮坪相砂岩。     

海侵背景下风暴控制的滨岸-陆棚砂体研究——以塔中志留系下沥青砂岩段为例

塔中志留系下沥青砂岩段发育海侵背景下受风暴控制的滨岸-陆棚沉积体系,沉积砂体的类型有滨岸砂、浅海砂坝和陆棚砂。风暴作用改造并控制着陆棚砂、浅海砂坝等砂体,使其发育规模增大。海侵时期形成的上述三种砂体的储集性优于海退时期形成的潮道砂体。滨岸砂、浅海砂坝和陆棚砂体区域上尖灭与陆棚泥岩组合,可形成较好的岩性地层圈闭。     

塔里木盆地满加尔凹陷西北缘上奥陶统铁热克阿瓦提组海相砂体类型与储集性

通过对羊屋2井、跃南2井、吉南1井等5口井岩心的精细描述、单井沉积微相与测井相分析及350 km地震剖面解释,认为在满加尔凹陷西北缘上奥陶统铁热克阿瓦提组海相砂泥岩沉积地层中发育5种重要的海相砂体,即滨岸（临滨-前滨）砂体、内陆棚沙脊砂体、内陆棚沟槽砂体、风暴砂体与潮道砂体。在等时地层格架内,研究区西部羊屋与哈得井区,铁热克阿瓦提组最底部分布着具有正韵律特点的、发育海侵砾岩与冲刷面的内陆棚沟槽砂体,其上为正反韵律均有且冲刷面不发育的较细粒内陆棚沙脊砂体,上部则是发育平行层理和冲洗交错层理的具明显反韵律特征的滨岸（临滨-前滨）砂体,顶部发育非均质性较强的风暴层砂体。在东部的吉南井区,下部发育内陆棚沙脊砂体,上部发育潮下带潮道砂体及潮间带砂坪沉积。受奥陶纪末期全球海平面下降影响,砂体分布范围逐步增大。铁热克阿瓦提组海相砂岩储集体以次生孔隙为主,非均质性比较强,导致储集层非均质性的主要原因是不均匀胶结作用、溶解作用以及局部发育有裂缝。对比5种类型海相砂体的储集性,按优差排序依次是内陆棚沙脊砂体、滨岸（临滨-前滨）砂体、内陆棚沟槽砂体、潮道砂体与风暴沉积砂体。
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惠民凹陷中央隆起带沙四上亚段滩坝与风暴岩组合沉积

惠民凹陷沙四上亚段沉积时期,盆地边缘发育三角洲和扇三角洲沉积,受波浪和沿岸流的影响,在中央隆起带滨浅湖区形成了与岸线走向平行或斜交的滩坝砂体和风暴沉积。滩坝沉积成熟度较高,泥质含量少,岩性以中细砂岩和粉砂岩为主,也有少量砾石,砂岩中常见含双壳类化石、生物碎屑和炭屑。滩坝沉积可分为砂坝、砂滩和滩坝间微相,平面上该区滩坝砂体可分为近岸砂滩、近岸砂坝、坝间砂滩、远岸砂坝、远岸砂滩、水下隆起处砂坝和水下隆起处砂滩。此外,受风暴浪的影响,在浪基面和风暴浪基面之间的地带形成风暴沉积,主要由块状层理段、递变层理段、丘状交错层理段、平行层理段和块状泥岩段构成。该组合沉积体系的形成主要受古地形、物源性质、湖平面变化等方面的影响。     

湘中涟源下石炭统的陆源碎屑风暴岩

描述了测水组具丘状层理的石英砂岩风暴岩和具丘状层理的粉砂岩风暴岩以及邵东组的具粒序层理的粉砂质风暴岩和泥质介壳层风暴岩,四种风暴岩的环境分布依次为前滨——上临滨、下临滨——过渡带、远滨或滨外泥质陆棚。     

湖南桃江半边山先寒武纪马底驿组陆屑风暴岩

本区马底驿组陆屑风暴岩的沉积构造非常清晰,其中有丘状交错层理、差异层理、层面构造、袋模、渠模、韵律层理和多种准同时变形构造.剖面可分为由块状层和韵律层组成的八个一级韵律,块状层为含砾泥质粉砂岩,韵律层由一系列二级韵律组成.根据沉积构造特征,自下而上划分为:斜坡带风暴浊流沉积、外陆棚风暴碎屑流沉积和陆棚风暴碎屑流沉积,海水逐渐变浅,为一海退层序。     

西天山阿吾拉勒一带石炭系阿克沙克组风暴岩及其意义

西天山阿吾拉勒阔尔库一带早石炭世阿克沙克组以海相碳酸盐岩夹碎屑岩为主,发育典型风暴成因的竹叶状砾屑灰岩。风暴沉积构造主要有风暴侵蚀构造、风暴撕裂构造、风暴浪构造、风暴涡流构造及风暴期后快速沉积构造等。已识别出的风暴沉积类型有具块状层理的竹叶状砾屑灰岩,具递变层理的砾屑灰岩和砾屑砂岩,具丘状、洼状交错层理和平行层理的砂屑灰岩及生物碎屑砾屑粉砂质灰岩,具平行层理的砂屑灰岩、长石岩屑砂岩,具波痕交错层理的砂屑灰岩和砾屑粉砂质灰岩,具水平层理的粉屑灰岩和具块状或水平层理的生物碎屑砾屑粉砂质灰岩。新发现的风暴沉积,说明早石炭世该地区处于低纬度带陆棚浅水沉积环境,因而对于分析西天山石炭纪的古地理、古气候、古构造及板块的运动规律具有重要意义。     

豫西前寒武纪汝阳群和洛峪群中风暴沉积

豫西前寒式纪汝阳群和洛峪群中广泛发育不同类型的风暴岩,主要包括丘状交错层砂岩、洼状交错层砂岩、浅水浊积岩以及与风暴作用有关的硬底、凝缩层和层间砾岩。不同类型风暴署具有不同的岩相组合及形成过程,并且发育在浅海陆棚的不同沉积带中。由洼伏交错层砂岩为主的相组合代表了滨岸带的下部;丘状交错层砂岩相组合指示风暴浪基面以上的内陆棚;而浅水浊积岩相组合则主要发育在外陆棚沉积区。这种风暴岩的沉积模式可用于详细恢复受风暴影响的古陆棚环境。     

滇中中元古代昆阳群因民组碎屑风暴岩及其意义

滇中地区中元古代昆阳群因民组以碎屑岩为主,内发育典型的风暴沉积构造 (包括渠铸型、丘状交错层理和洼状交错层理、递变层理等 )。风暴沉积主要包括 4种岩相类型 :A -具口袋构造的递变层理砂岩段。B -具丘状或洼状交错层理的砂岩段。C -具均质层理的粉砂岩、泥质岩段。D -具水平层理的泥质岩段。上述岩相A、B、C分别代表风暴流作用 -风暴浪作用 -风暴后期的快速悬浮沉积 (事件沉积 ),D代表风暴过后缓慢悬浮沉积 (背景沉积 ),它们组合成不同的风暴沉积序列。滇中地区昆阳群风暴沉积的发现表明中元古代大气圈、水圈及其相互作用与现今近似;中元古代滇中地区位于低纬度 (5 - 30°)的风暴作用带。该沉积对于解释因民组递变层砂岩的成因、证实昆阳群的地层层序也具有重要意义。     

徐州地区震旦系贾园组的风暴沉积

徐州地区震旦系下部的贾园组具有丰富典型的风暴沉积标志,包括各种冲刷－充填构造、丘状交错层理、碎屑流沉积、粒序层理及卷曲层理等。通过详细的野外观测及室内研究,根据风暴沉积标志的组合可划分出6种风暴沉积序列类型。其中,类型Ⅰ为具粒序层理的薄层含粉砂灰岩,形成于风暴浪基面以下的远源风暴浊流的末梢;类型Ⅱ以渠模与丘状交错层理的组合为特征,出现在风暴浪基面与晴天浪基面之间;类型Ⅲ为风暴流成因的碎屑流沉积内碎屑灰岩与底面的冲刷沟槽、丘状交错层理的组合,是形成于晴天浪基面附近的槽道碎屑流型风暴沉积;类型Ⅳ为具颗粒流沉积特征的内碎屑灰岩与冲刷面构造及丘状交错层理的组合,丘状纹层段中常见卷曲层理,形成于滩前陆棚斜坡的上部;类型Ⅴ为夹于湖相薄层灰岩中的鲕粒砾屑灰岩,为风暴水流冲越鲕滩,在滩后湖近滩一侧的风暴沉积;类型Ⅵ为湖相风暴岩,由冲刷面构造、薄层内碎屑灰岩及丘状交错层理的组合,顶部具晴天沉积。各种序列在垂向上叠置,构成向上变浅序列。风暴沉积的研究对于深化区域古地理及地层对比研究具有重要的理论和现实意义。     

内蒙古东乌旗地区中下泥盆统泥鳅河组沉积相研究

发育于内蒙古东乌旗地区的泥鳅河组,属于早中泥盆世沉积,厚度约1000m,主要发育泥岩、粉砂岩和灰岩沉积,粉砂岩中常常发育大量腕足类和珊瑚生物化石。首次在本区发现风暴沉积和Beaconites遗迹化石:风暴沉积由下至上包括粒序层理段、平行层理段、丘状交错层理段和浪成波纹层理段4个层段;Beaconites遗迹化石具管壁和内部水平“V”字型的回填纹构造。通过对岩相、生物化石、风暴沉积和Beaconites遗迹化石的研究显示,东乌旗地区泥鳅河组为浅海相沉积。     

Fluvial, tidal and storm sedimentation in the Chilhowee Group (Lower Cambrian), northeastern Tennessee, U.S.A.

The Lower Cambrian Chilhowee Group of northeastern Tennessee consists of the Unicoi, Hampton and Erwin Formations, and is divided into four facies. The conglomerate facies occurs only within the lower 200 m of measured section (the Unicoi Formation) and consists of fine-grained to pebbly quartz wacke with rare thin beds of laminated siltstone. Low-angle to horizontally laminated, fine-grained sandstone with laminae and lenses of granules and pebbles represents upper flow-regime, overbank deposition within a braided stream system that was close to a coastline. Medium-scale, planar-tabular cross-stratified conglomerate in which megaripple bedforms are preserved is interpreted as representing deposition in interbar pools of braided channels, as flood stage waned and larger bedforms ceased to migrate. Large-scale, planar-tabular cross-stratified conglomerate beds represent migration of large transverse bars within a broad braided stream channel during high flood stage. The sandstone facies occurs throughout the Chilhowee Group, and is therefore interbedded with all other facies. It consists of mainly medium- to very coarse-grained, subarkosic to arkosic arenite. Thinly interbedded, laminated siltstone and sandstone, which may exhibit wavy or lenticular bedding, represents deposition during slack water periods between ebb and flood tides. Large-scale planar-tabular and trough cross-stratification reflects deposition within the deepest areas of subtidal channels, whereas medium-scale cross-stratification represents deposition in shallower water on shoals separating channels. Fining- and thinning-upward sequences most likely resulted from the longshore migration of channels and shoals. The hummocky facies occurs only in the Erwin Formation and consists of horizontally laminated to hummocky stratified, fine-grained arkosic to subarkosic arenite interbedded with equal amounts of bioturbated mudstone. It represents deposition between storm and fairweather wave-base by combined-flow storm currents. The quartz arenite facies is characterized by an absence of fine-grained units and lithologically consists of a super-mature, medium- to coarse-grained quartz arenite. Large-scale planar-tabular cross-stratification and abundant low-angle cross-stratification with rare symmetrical ripples (lower quartz arenite facies) occurs interbedded with the braided fluvial conglomerate facies, and was deposited within either a ridge-and-runnel system or a system of nearshore bars. Large-scale, planar-tabular cross-stratification (upper quartz arenite facies), which forms the top of two 40 m-thick coarsening-upward sequences of the type: hummocky faciessandstone faciesquartz arenite facies, probably represents deposition on sand ridges that formed on a sand-starved shelf as transgression caused the detachment and reworking of shoreface channel-shoal couplets. Palaeocurrent data for the Chilhowee Group are unimodal but widely dispersed from 0° to 180°, and exhibit a minor mode to the west. The data are interpreted to reflect the influence of longshore, tidal and storm currents. The ichnofossil assemblage changes upsection from one characterized only by Paleophycus to a Skolithos ichnofacies and finally to a Cruziana ichnofacies. The facies sequence, biogenic and palaeocurrent data reflect the interaction through time of (I) non-marine and marine processes; and (2) transgression coupled with shoreline progradation. The Chilhowee Group represents an overall deepening from terrestrial deposition to a marine shoreface that experienced both longshore and tidal currents, and finally to a storm shelf environment that periodically shoaled upward.     

广西北海涠洲岛第四纪湖光岩组的风暴岩

广西北海涠洲岛第四纪湖光岩组以碎屑岩为主, 内发育渠筑型、丘状或洼状交错层理、平行层理等典型的风暴沉积构造.湖光岩组的风暴岩包括3种岩相类型: A.底部具渠筑型、内部具块状层理或递变层理的砾岩、砂砾岩或含砾砂岩; B.具丘状、洼状交错层理或平行层理的砂岩; C.具浪成交错层理的砂岩.这些岩相组合成典型的A -B -C风暴沉积序列, 它们分别代表在风暴作用期间风暴流(A)、风暴浪(B) 和正常波浪(C) 的沉积.晚更新世北海涠洲岛地区位于低纬度的浅海沉积背景下, 上更新统湖光岩组以正常浪及面之上的浅海背景粗火山碎屑和砂沉积为主.湖光岩组风暴岩的发现反映该区晚更新世位于风暴作用频繁的5°~ 2 0°的低纬度地区.风暴沉积发育于正常浪及面之上的浅海地带, 涠洲岛是一个风暴作用控制的浅海陆架.因此风暴岩对解释晚更新世北部湾的古地理和古气候具有重要意义      

Shallow marine sedimentation in the proterozoic moine succession,northern Scotland

Shallow marine deposits are recognised from the Loch Eil division of the Proterozoic Moine Succession. Three sedimentary facies are identified: siltstone, interbedded siltstone and sandstone, and sandstone. The bulk of the succession comprises sandstones which are commonly cross-bedded. Bipolar cross-bedding is indicative of tidal activity, and the facies is considered to have accumulated in an offshore shallow marine setting. The interbedded siltstone and sandstone facies and the siltstone facies are similarly interpreted as offshore sediments deposited in areas characterised by relatively high rates of silt deposition and starvation of sand. Calc-silicate rocks represent concretions formed during diagenesis. Palaeocurrents derived from the lower part of the succession mainly flowed to the north-northeast with a subsidiary mode to the south-southwest, and probably represent longshore currents flowing broadly parallel to a palaeocoastline.     

从岩相古地理看柴达木盆地侏罗系的油气前景

在前人研究的基础上，利用20余处露头剖面、150余口钻井剖面和12 000 km地震剖面资料，特别是最新的钻探成果，对柴达木盆地侏罗纪的岩相古地理进行了重新认识，通过岩相古地理编图，指出了侏罗系地层和沉积相的展布规律，确定了生油凹陷和储集砂体的分布位置，预测了侏罗系油气远景。早、中侏罗世的古气候条件有利于油气的生成，多个古凸起提供的多个物源,有利于储集砂体的形成，确定了辫状河三角洲砂体、滨湖席状砂体、滨浅湖滩坝砂体、河道砂体、浊积扇砂体和近岸水下扇砂体等6种沉积类型和30个有利和较有利的储集砂体。众多半深湖-深湖区提供丰富的油气资源，确定了8个大小不等的生油凹陷，累积面积超过4000 km2。古地理的演化表明该区发育多套生储盖组合。最后指出冷湖地区、昆特依地区、马海尕秀-鱼卡地区等是今后勘探的有利地区。     

Upper Cretaceous Gongila Formation in the Hawal Basin, northeast Benue Trough: a storm and wave dominated regressive shoreline complex

The Gongila Formation in the Hawal Basin displays lithological characteristics, textural variations and sedimentary structures that facilitate palaeoenvironmental reconstruction. The 41 m thick Gongila succession is divisible into: (i) a mudstone facies association (at the bottom) composed of fossiliferous limestone, clay shale, and sharp-based, graded and swaly-bedded shell debris; and (ii) a cross-stratified sandstone facies association that constitutes the uppermost 60% of the entire succession. The cross-stratified sandstone facies association is further subdivided, on the basis of sedimentary structures, into: (i) a lower interval represented by a coarsening upward fine- to medium-grained sandstone, siltstone and shale in which units characterised by parallel lamination and hummocky cross-stratification pass upward through a zone of small-scale low angle cross-stratification into units characterised by planar cross-stratification and sparse Teichichnus and Skolithos burrow traces; and (ii) an upper interval dominated by fine- to medium-grained sandstone and bioturbated siltstone characterised by erosive based, high angle tangential foresets, subhorizontal laminations and burrow structures belonging to the Thalassinoides, Ophiomorpha and Skolithos ichnogenera.The overall sequence of the Gongila Formation represents progradation on a wave influenced coast, passing from shelf mudstone at the base to lower and upper shoreface sandstones at the top. Each facies association displays an alternation between relatively high energy conditions when sediment was mainly deposited by decelerating suspension laden currents, and relatively low energy conditions when wave reworked fine-grained sediment as it was deposited from suspension. The influence of storms in these conditions is inferred from the associated lithofacies, textural characteristics and sedimentary structures.     

Significance of pot and gutter casts in a Middle Triassic carbonate platform, Betic Cordillera, southern Spain

Pot casts and gutter casts are described for the first time in the lower part of the Majanillos Formation, a Middle Triassic carbonate unit located in the External Zones of the Betic Cordillera (southern Spain). Their identification, as well as their relation to tempestites, enables the better interpretation of the depositional environments and the shoreline-to-offshore facies transition on the Anisian muddy carbonate ramp of the southern Iberian Massif. The Majanillos Formation contains three members, which become progressively more marly towards the top. Well-preserved pot and gutter casts and thin intercalations of calcarenite, which are interpreted as tempestites, are abundant in the lowest member. Above the pot and gutter casts, thicker calcarenite beds, which locally contain hummocky cross-stratification, predominate. Bioturbated nodular limestones are prevalent at the top of the member. The remaining succession, which records a long-term Triassic transgressive cycle, consists mostly of fine-grained limestones deposited in very shallow-marine environments. Calcarenitic sediments only accumulated within potholes and gutters in the nearshore. They developed during storms when strong currents transported sediment to the outer shelf, where it was deposited as tempestite beds. Pot and gutter casts characterize sedimentation in the bypass zone. It is concluded that storm deposits provide important constraints for the interpretation of palaeobathymetry; it is proposed that gutter casts display a trend of increasing width/thickness ratios towards the outer shelf. The identification of these structures in marine successions elsewhere should prove useful in the interpretation of depositional environments.