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中国河流沉积学研究20年 总被引：19，自引：4，他引：15
从河型及其分类研究、现代河流沉积调查、河流沉积相与相模式研究、河流相地层的层序地层学研究、河流沉积砂体建筑结构精细解剖、河流沉积模拟研究等六个方面回顾了自《沉积学报》创刊以来20年中国河流沉积学研究的主要进展,指出我国的河流沉积学取得了许多富有特色的研究成果,主要表现在网状河概念的引入与普及、建筑结构要素分析法的推广、界面层次的划分和及其概念的扩张、岩石相类型和岩石相组合概念的应用、河流砂体露头调查的方法与技术、沉积构造的沉积动力学解释、层序地层学在河流沉积研究中的应用、河流沉积过程的模拟实验、河流相储层的建模技术等方面。但是20年来,中国河流沉积学研究并没有出现国际公认的理论首创,应当加强河流沉积学的研究组织,吸收地理地貌和水利学的研究成果,结合社会经济建设需要不断扩大河流沉积学的研究领域,积极进行国际学术交流,使我国的河流沉积学研究走在国际河流沉积学研究的前列。 相似文献
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渤海湾中部南堡35-2地区新第三系河流沉积及油气勘探意义 总被引：4，自引：8，他引：4
渤海湾中部南堡35-2地区新三系河流沉积十分发育，可分为曲流河沉积和辫状河沉积两种类型。曲流河沉积以发育点砂坝、决口扇、天然堤和泛滥平原等微相单元为特征。辫状河沉积主要发育河道和心滩微相，泛滥平原微相不太发育。本重点研究了河流沉积各类微相的沉积特点，并将河流沉积的垂向层序归纳为6种类型。本还探讨了各类砂体的储集物性特征，认为点砂坝和心滩砂体是形成大油气田的优质储层，而油气藏的形成除与砂体的储集物性有关外，主要与区域构造条件密切相关。 相似文献
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河流沉积是陆相沉积环境和地层记录的重要组成部分,也是陆相盆地重要的油气储层。侏罗系延安组是鄂尔多斯盆地重要的含煤和储油层系。延安组早期河流沉积发育,延安一带出露典型沉积剖面,是剖析河流构型特征的难得窗口。采用沉积学理论和构型要素分析方法,在野外露头精细解剖的基础上,分析了延安组下部辫状河、曲流河的沉积构型特征,探讨了古河道规模和河流类型转化的控制因素。研究表明,延安组延10沉积期辫状河发育,主要由河道、顺流加积体和沙质坝等单元组成,多期河道沉积叠置,呈厚层板状分布,泥质隔夹层不发育;延9早期演变为曲流河,发育河道、侧向加积体、废弃河道、泛滥平原及决口扇等构型单元,泥质隔夹层较发育,砂体连续性变差。采用经验公式估算,延10辫状河河道宽度为19.34~373.22 m,延9曲流河河道宽度16.81~99.21 m。延安组早期继承了富县组沉积期的古构造—古地理格局,随着填平补齐的发展和盆地沉积范围的扩大,古地形变缓,物源供给减弱,导致河流类型由辫状河演变为曲流河。研究结果对于深入理解同物源体系供给条件下河流沉积构型特征及类型转换,油气储层预测等具有理论和现实意义。 相似文献
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应用印模法恢复了鄂尔多斯盆地前侏罗纪古地貌形态。研究表明，区内古地貌格局由“三斜坡、三河谷、两河间丘和一梁”组成，即姬塬东斜坡、定边斜坡、靖边斜坡，宁陕河谷、蒙陕河谷、甘陕河谷，吴旗河间丘、金鼎河间丘和新安边梁。前侏罗纪古地貌控制着下侏罗统延安组早期沉积。延10段属河流相沉积环境，发育的沉积微相有主河道、支流河道、河漫滩、河漫沼泽。延9段沉积环境为三角洲到湖泊环境，沉积相主要由三角洲平原亚相、三角洲前缘亚相组成，沉积微相以分流河道、分流间洼地、水下分流河道和分流间湾为主。相同的古地貌单元、不同的沉积环境，必然造成储集砂体形态特征及分布规律的变化，进一步影响油藏的形成和分布。古地貌油藏的形成除受油源、圈闭等基本条件制约外，古地貌 沉积组合和油气运移通道也是形成不同类型古地貌油藏的重要条件。依据已探明油田的空间分布结合古地貌、上覆地层沉积环境、砂体展布、运移通道类型等多种因素归结出定边-吴旗地区古地貌油藏三种成藏模式，即斜坡区-三角洲平原组合成藏模式、河间丘区-三角洲前缘组合成藏模式和斜坡区-三角洲前缘组合成藏模式。 相似文献
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前人对河流沉积特征的总结主要针对砂质曲流河和砾质辫状河,但几乎未涉及砾质曲流河类型.以秦皇岛地区大石河北庄坨村-上庄沱镇河段为例,通过现代沉积学考察,描述了砾质曲流河的地貌单元和沉积特点,总结了沉积序列和沉积模式,探讨了该类河流的成因机制.其地貌单元包括高弯曲的单河道、交替分布于河道两侧的凹岸-凸岸、流槽和河漫滩.受两侧山地的近物源供给,自下而上发育河床底部滞留沉积和砾质曲流沙坝、砂砾质流槽、砂质河漫滩沉积,具叠瓦状构造和大型板状-楔状-槽状交错层理,总体呈现正旋回序列和不典型的二元结构.砾质曲流河在地貌形态上与砂质曲流河类似,但在水动力条件、沉积物岩性组成和沉积序列方面与砾质辫状河类似,表现为双重性质.依据研究区3级河流阶地,结合该类河型在现今山地普遍分布的特点,分析指出砾质曲流河的成因在于区域构造抬升和河流强烈侵蚀下切.本文研究对河型分类、分布及控制因素的认识带来了挑战.鉴于砾质曲流河响应于区域构造抬升的特点,地史时期该类河型的识别必然对造山运动具有重要指示意义. 相似文献
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通过对库车河剖面下白垩统巴西改组—古近系库姆格列木群底部的沉积露头实测,分析砂岩岩性组合、沉积构造特征、砾岩特征及沉积古环境,并结合现代天山南北季节性河流沉积特征,认为干旱气候条件下发育的季节性河流及季节性河流三角洲是白垩纪库车坳陷发育的重要沉积体系.下白垩统巴什基奇克组砂岩特征与现今广泛发育的季节性河流沉积特征极为相似,既有较为典型的河流相正韵律砂体大面积沉积,河道底部内碎屑泥砾与厚层块状的大型交错层理等砂岩,又显示出高能细砂岩和高能粉砂岩沉积,并具有较低的成分成熟度和较高的结构成熟度基本特征.在此基础上,建立了库车河剖面下白垩统巴西改组—巴什基奇克组沉积相模式:巴西改组沉积时期,库车坳陷发育面积较大的宽浅型湖泊,天山前发育的季节性河流进入湖泊后形成季节性河流三角洲;巴什基奇克组沉积时期,古天山前出现了多个小型湖泊,古天山山前发育大量的季节性辫状河与多个小型季节性辫状三角洲沉积. 相似文献
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断陷湖盆缓坡河流成因砂体是重要的油气储集单元。根据岩心观察、钻井岩/电特征并结合地震沉积学方法,分析断陷湖盆缓坡河流沉积体系和砂体时空分布特征,能为油气精细勘探提供可靠的依据。研究表明,霸县凹陷文安斜坡中部东营组三段周期性地发育4条呈NE-SW辫-曲复合型河流沉积,由河道沉积、砂坝沉积和泛滥平原沉积3种亚相以及辫状河道、曲流河道、砂质河道砂坝、泥质河道砂坝、决口扇和泛滥平原泥6种微相构成。河流展布方向与正北夹角(α)为40°~65°,河道视宽度(l)为1.47~2.64 km,主河道的视宽度(w)为0.03~0.58 km,河道带测量厚度(H)为16.0~52.0 m,主河道测量厚度(D)为8.0~23.0 m,主河道钻井解释厚度(d)为1~16.5 m,平均厚度6.5 m。断陷盆地断-坳转换期缓坡河流相沉积受控于盆地构造、气候、物源、沉积物压实及流速等多因素。边界断层差异性活动导致的盆地不均衡沉降是缓坡带河流相类型及砂体空间分布的主控因素。气候周期性变化通过流量控制了河型,调整和改造早期河道沉积物,决定了微相和砂体组合。斜坡中外带是粗粒沉积物主要卸载区,河道及河道砂坝等优势储集砂体呈条带状连片分布,斜坡内带形成的厚层泥岩限制油气垂向运移和侧向充注。斜坡中外带被油源断层切割,在油气运移路径上受晚期断层切割的厚层河道及河道砂坝是岩性-构造油气藏勘探的潜力区域。 相似文献
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通过对新疆现代白杨河冲积扇的地貌和现代沉积进行调查，发现冲积扇表面发育两种不同类型的河道，一种为季节性河道，另一种为暂时性河道。暂时性河道内水流占有率小于50%直至接近于0，主要由暴雨形成突发性洪水造成，季节性河流河道内流水占据率为50%左右，输出水流特征介于暂时性河道和常年性河流河道之间。白杨河主河道属于季节性河道，河道占冲积扇表面面积2.1%，沉积物以砾石质为主，颗粒粗、磨圆度高、分选较好，泥质含量低、叠瓦状排列特征明显，沉积物具有向下游变细的趋势，河道形态沿程变化明显。暂时性河道占冲积扇表面面积97.9%，沉积物粒度相对较细，磨圆度低、分选差、泥质含量高，河道规模向下游减小，分叉增多。季节性河道以河道径流为主，暂时性河道主要以片流、泥石流等方式搬运沉积物。季节性河道沉积物主要来自上游较远的源区，暂时性河道的沉积物来源于冲积扇扇根附近基岩风化形成的倒石锥，塌积扇和山地泥石流沉积，一部分来自于对冲积扇原有沉积物的改造、搬运和再沉积。季节性河道是形成冲积扇扇体的主要动力，暂时性河道主要对冲积扇起改造作用。研究深化了对干旱地区冲积扇沉积过程和沉积特征的认识，丰富了冲积扇的沉积模式。 相似文献
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陕北东部地区长2+3油层组远源砂质辫状河沉积特征 总被引：2，自引：1，他引：2
通过地表露头与钻井剖面的观测分析综合研究,证实陕北东部地区长2 3油层组属于在泛滥平原下游发育的远源砂质辫状河沉积。沉积类型可划分出河道亚相与泛滥平原亚相等两个亚相以及河床滞留、河道砂坝、天然堤、决口扇、泛滥平原等5个可识别的微相。河道砂坝为其沉积的主体。长3到长2期,远源砂质辫状河沉积在平面展布和剖面组合上均表现出向三角洲相区持续推进和逐步超覆的特点。远源砂质辫状河沉积在其平面相区内一般无明显的、限制性的河道表现,河道砂坝复合连片,形成大规模的砂坪或广泛分布的"叠覆泛砂体"沉积,泛滥平原发育区仅在局部有所残留;剖面组合上河道砂坝极为发育,复合迭加程度高,形成连续性和连通性良好的宽厚的复合河道砂坝砂体以及"砂包泥"的沉积组合。同时,远源砂质辫状河流的发育使得与其相邻的三角洲沉积具有了类似"辫状河三角洲"的性质和特点。 相似文献
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河流沉积学研究热点与进展--第11届国际河流沉积学大会综述 总被引：1，自引：1，他引：0
第11届国际河流沉积学大会于2017年7月17日-21日在加拿大卡尔加里大学举行，每四年举行一次的国际河流沉积学学术会议，吸引了当今北美、欧洲、澳洲及亚洲从事河流沉积学及相关学科研究的众多知名学者参会，研究成果充分体现了当前国际河流沉积学研究取得的重要进展和发展方向。重要进展有:1）河流动力学及其变化过程研究。其中包括将今论古法论现代河流沉积过程与古老地层对比，河道-洪泛平原体系的越岸复合沉积动力学，河流动力学与变化过程研究展望，恢复河道迁移过程:新一代平面图演化模式的讨论，冲积河流和基岩河流的湍流、颗粒间作用和沉积作用；2）陆缘河流。包括河流入海处的地貌动力学与沉积学，河流补给边缘的沉积物搬运、地貌和地层特征，干旱地区河流、冲积扇体系与风的相互作用，植被生长前、无植物生长、或是植被发育区河流的沉积过程研究；3）河流沉积地层及其地下资源。包括源-汇系统，"河流相模式"是否有用的讨论，辫状河、网状河、曲流河概念的厘定等；4）河流地貌变化。包括气候改变、泥泞植被洪泛平原等对河流沉积物通量、河流模式等产生影响，河道中冲积岛屿的演化和稳定河流的蛇曲化，河流环境中沉积物生物作用等。基于上述资料分析，认为河流演化过程从定性向定量化研究，物理模拟与数值模拟技术是河流沉积学研究不可或缺的手段，应用定量建模、数学计算等方法进行精准研究，碎屑锆石U-Pb定年技术是新一代从源到汇研究的重要工具等诸多方面，是我国学者应该重视并开展研究的方向。 相似文献
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嫩江是松辽盆地北部一条多河型河流。本文以黑龙江省富裕县塔哈乡大马岗嫩江现代河流沉积露头为例,运用Miall结构要素分析法对嫩江现代河流沉积体岩相类型、层次界面及内部构形要素进行了系统研究,表明大马岗沉积体主要由块状层理细砾相、大型及小型低角度槽状交错层理细砂相、同沉积变形层理细砂相、波状交错层理细砂相、薄层状粉砂质泥与细砂互层相、微波状层理粉砂相、块状层理泥质粉砂相、水平层理泥相、块状层理粉砂质泥相等16种岩相构成,不同岩相空间分布变化差异较大。在大马岗沉积体内部识别出1～5级层次界面,划分出具有成因意义的7种构形要素:河道、砾质坝、侧向加积沉积体、单一侧积砂层、纹层砂席、砂底形及越岸细粒沉积,这种构形要素的划分丰富了Miall的分类方案。 相似文献
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Modern fluvial meander plains exhibit complex planform transformations in response to meander‐bend expansion, downstream migration and rotation. These transformations exert a fundamental control on lithology and reservoir properties, yet their stratigraphic record has been poorly evaluated in ancient examples due to the lack of extensive three‐dimensional exposures. Here, a unique exhumed meander plain exposed to the north of Scarborough (Yorkshire, UK) is analysed in terms of architecture and morphodynamics, with the aim of developing a comprehensive model of facies distribution. The studied outcrop comprises tidal platforms and adjacent cliffs, where the depositional architecture of un‐tilted deposits was assessed on planform and vertical sections, respectively. In its broader perspective, this study demonstrates the potential of architectural mapping of extensive planform exposures for the reconstruction of ancient fluvial morphodynamics. The studied exhumed meander plain is part of the Scalby Formation of the Ravenscar Group, and originally drained small coastal incised valleys within the Jurassic Cleveland Basin. The meander plain is subdivided into two storeys that contain in‐channel and overbank architectural elements. In‐channel elements comprise expansional and downstream‐migrating point bars, point‐bar tails and channel fills. Overbank elements comprise crevasse complexes, levées, floodplain fines and lake fills. The evolution of the point bars played a significant role in dictating preserved facies distributions, with high flood‐stage nucleation and accretion of meander scrolls later reworked during waning flood‐stages. At a larger scale, meander belt morphodynamics were also a function of valley confinement and contrasts in substrate erodibility. Progressive valley infilling decreased the valley confinement, promoting the upward transition from prevalently downstream migrating to expansional meander belts, a transition associated with enhanced preservation of overbank elements. Strikingly similar relations between valley confinement, meander‐bend transformations and overbank preservation are observed in small modern meandering streams such as the Beaver River of the Canadian prairies and the Powder River of Montana (USA). 相似文献
14.
Traditional facies models lack quantitative information concerning sedimentological features: this significantly limits their value as references for comparison and guides to interpretation and subsurface prediction. This paper aims to demonstrate how a database methodology can be used to generate quantitative facies models for fluvial depositional systems. This approach is employed to generate a range of models, comprising sets of quantitative information on proportions, geometries, spatial relations and grain sizes of genetic units belonging to three different scales of observation (depositional elements, architectural elements and facies units). The method involves a sequential application of filters to the knowledge base that allows only database case studies that developed under appropriate boundary conditions to contribute to any particular model. Specific example facies models are presented for fluvial environmental types categorized on channel pattern, basin climatic regime and water‐discharge regime; the common adoption of these environmental types allows a straightforward comparison with existing qualitative models. The models presented here relate to: (i) the large‐scale architecture of single‐thread and braided river systems; (ii) meandering sub‐humid perennial systems; (iii) the intermediate‐scale and small‐scale architecture of dryland, braided ephemeral systems; (iv) the small‐scale architecture of sandy meandering systems; and (v) individual architectural features of a specific sedimentary environment (a terminal fluvial system) and its sub‐environments (architectural elements). Although the quantification of architectural properties represents the main advantage over qualitative facies models, other improvements include the capacity: (i) to model on different scales of interest; (ii) to categorize the model on a variety of environmental classes; (iii) to perform an objective synthesis of many real‐world case studies; (iv) to include variability‐related and knowledge‐related uncertainty in the model; and (v) to assess the role of preservation potential by comparing ancient‐system and modern‐system data input to the model. 相似文献
15.
河型研究是河流动力学及河流工程学中的一个基本问题,也是沉积学家判别地下不同成因砂体的一个关键问题。目前河型的分类大都基于河流的平面形态,而这一分类受到了越来越多的质疑,并提出了一些新的分类方案,许多研究者注意到河型并不是离散的,存在一系列连续变化的河型,同时,顺直河、曲流河以及辫状河这些常见的河型之间可能发生突变,河型转化是当前国际河流学界研究的前缘和薄弱环节。本文通过综述河型转化在现代沉积、模拟实验、露头以及地震四个方面的研究进展,认为河型转化主要受到构造作用、沉积物供给、气候条件和海(湖)平面变化四大因素控制,其中前三个因素对于古河型的演化至关重要。在上述因素的影响下,一条河流从上游往下游,往往具有由辫状河→低弯度曲流河→高弯度曲流河→网状河的演化规律。但是河流的位置并不是决定上述变化的主要因素,只要符合条件,即构造作用、沉积物供给及气候等因素发生重大变化的情况下,河型就可能发生转化。然而,河型转化的研究成果尚未引起石油地质学家们的足够重视,并没有被充分的应用到古代河流的解释中去,这将是今后的一个重点研究方向。 相似文献
16.
Marina D. Coronel Manuel F. Isla Gonzalo D. Veiga Nigel P. Mountney Luca Colombera 《Sedimentology》2020,67(5):2596-2624
In terminal fluvial-fan systems, characteristic proximal to distal variations in sedimentary architectures are recognized to arise from progressive downstream loss of water discharge related to both infiltration and evaporation. This work aims to elucidate downstream trends in facies and architecture across the medial and distal zones of terminal-fan systems, which record transitions from deposits of channel elements to lobe-like and sheet-like elements. This is achieved via a detailed characterization of ancient ephemeral fluvial deposits of the well-exposed Kimmeridgian Tordillo Formation (Neuquén Basin, Argentina). The fine sand-prone and silt-prone succession associated with the medial to distal sectors of the system has been studied to understand relationships between depositional processes and resulting architectures. Facies and architectural-element analyses, and quantification of resulting sedimentological data at multiple scales, have been undertaken to characterize sedimentary facies, facies transitions, bed types, architectural elements and larger-scale architectural styles. Eight bed types with distinct internal facies transitions are defined and interpreted in terms of different types of flood events. Channelized and non-channelized architectural elements are defined based on their constituent bed types and their external geometry. The most common elements are terminal lobes, which are composite bodies within which largely unconfined sandy deposits are stacked in a compensational manner; a hierarchical arrangement of internal components is recognized. Proximal feeder-channel avulsion events likely controlled the evolution of terminal-lobe elements and their spatiotemporal shifts. Stratigraphic relations between architectural elements record system-wide trends, whereby a proximal sector dominated by channel elements passes downstream via a gradational transition to a medial sector dominated by sandy terminal-lobe elements, which in turn passes further downstream to a distal sector dominated by silty terminal lobe-margin and fringing deposits. This work enhances current understanding of the stratigraphic record of terminal fluvial systems at multiple scales, and provides insight that can be applied to predict the facies and architectural complexity of terminal fluvial successions. 相似文献
17.
为了解辽河盆地滩海地区东二段沉积相类型,通过现代河流沉积调研以及岩心、测井、地震相综合分析,结果证明:滩海地区东二段沉积相类型主要以滨浅湖-滩坝相为主,而非地震属性图所反映的河流相沉积,地震属性解释存在误区。古沉积环境解释最重要的因素就是如何理解"保存"的概念。河流在自身演化过程中迁移、改道时常发生,在漫长的地质时间内,难以保存一个完整的河道。沉积环境分析中,应当遵循从岩心相—测井相—地震相的分析过程,而不是单纯依据地震属性直接进行沉积相研究。 相似文献
18.
Reappraisal of Precambrian sheet‐braided rivers: Evidence for 1·9 Ga deep‐channelled drainage 
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下载免费PDF全文 The repetitive sedimentology of many Precambrian sheet‐dominated fluvial sandstones favoured their attribution to unconfined depositional processes. This article presents outcrop evidence for deep‐channelled drainage in the 1·9 Ga Burnside River Formation of Kilohigok Basin, Arctic Canada. On the ground, sheet‐like sandbodies with ubiquitous cross‐bedding are at first consistent with classic, unconfined depositional models. However, satellite and oblique‐aerial imagery of sections up to 15 km wide and 500 m thick reveals the occurrence of incised palaeovalleys hosting clustered, kilometre‐scale, channel bodies with attached large foreset bars pointing to downstream‐lateral accretion, sand sheets with aspect ratios (i.e. width to thickness) as high as 2500, and scattered aeolian intervals. The genetic association of these architectural elements points to aggradational fluvial piedmonts composed of low‐relief unit bars generated by braidplain channels several metres deep. Preservation of aeolianites was facilitated by fluctuating groundwater table and accommodation. Fluvial piedmonts were transected by weakly sinuous channel belts up to 25 m deep and characterized by through‐going or tributary planform. Aspect ratios comparable with those of late Palaeozoic to modern braided channels disprove the inference that all Precambrian streams readily widened in response to increased discharge. Previous facies models for large‐scale Precambrian sheet‐braided rivers failed to depict entire channel forms, possibly because they could not be resolved by ground‐based observations. Based on their limited geomorphic variability and abundance of architectural elements with very high aspect ratios, this study recommends that large sheet‐braided fluvial systems should still be considered separately from their post‐Silurian (i.e. vegetated) braided counterparts. Parallels between sheet‐braided and modern dryland rivers do not, however, reconcile with the deep, perennial, channelized processes described here. Yet, distal sand‐bed and perennial reaches of modern sandur plains remain the closest analogue to sheet‐braided rivers. This conjecture contradicts the assumption that all Precambrian rivers were prone to simulate seasonal behaviours independently from their actual climate regime. 相似文献
19.
L. Feng Y-C. Lu J. S. Wellner J-S. Liu X-F. Liu X.-Q. Li 《Australian Journal of Earth Sciences》2020,67(2):279-304
AbstractThe Xihu sag, which is the largest petroliferous sub-basin of the East China Sea Shelf Basin, formed in a continental back-arc setting. The Oligocene Huagang Formation consisting of a fluvial–lacustrine succession deposited during the compressional stage is the prime hydrocarbon-bearing interval in the Xihu sag. A third-order sequence-stratigraphic framework has been built, and component sand-body characteristics were investigated based on seismic attribute analysis and well-log correlation. Two overall upward-fining sequences, and an internal low-accommodation systems tract (LAST) (fluvial successions characterised by amalgamated fluvial channel sand bodies interlayered with rare overbank deposits) and high-accommodation systems tract (HAST) (intervals dominated by overbank or lacustrine deposits) have been identified. The thick, multi-storied channel-fill sandstone bodies deposited along the central depression belt, capped by extensive overbank or lacustrine mud deposits, characterise each sequence and form favourable reservoir–seal associations. Proximal-to-distal changes in lithofacies associations were also analysed. The sequence-stratigraphic and lithofacies analysis suggest the existence of an axial, large-scale river channel system in the Oligocene Xihu sag. On the basis of the restoration of basin geomorphology and seismic facies analysis, the depositional architectures of the axial paleodrainage system have been reconstructed. Overall, the Huagang sequences represent the sedimentary evolution of a large-scale fluvial system sourced from axial and lateral supply areas, to form river deltas into an interior-draining basin-centre lake. Two major fluvio-lacustrine transgression–regression cycles have been recorded. During the transgression cycle, the fluvial morphology was dominated by braided fluvial style; whereas during the regression cycle, the fluvial morphology was characterised by a combination of multiple fluvial channel styles in the LAST, from upstream to downstream low-sinuosity braided, high-sinuosity braided and anastomosing fluvial channel patterns were distributed and then replaced by large-scale lake flooding in the HAST. The braided channel centre, paleobathymetric lows of channel networks and delta-front bodies are sand-prone units. The fluvial sedimentation was governed by multiple parameters: tectonics, paleogeomorphology and climate fluctuations. This integrated study on fluvial sedimentation and evolution of the Oligocene drainage system enable us to propose a conceptual model depicting fluvial channel styles and component sand-body architecture in lacustrine rift basins with axial plus transverse sediment supplies. This model can serve as a reference to illustrate channel-sand-body and associated reservoir architecture in similar types of drainage systems in terrestrial basins. 相似文献