The three‐dimensional facies and architecture variability of shelf‐edge deltaic units cropping out at the transition between the Lower–Middle Jurassic Lajas and Los Molles formations of southern Neuquén Basin, Argentina, is presented here, as well as their stratigraphic relationship to uppermost deep‐water slope channel systems. Deep‐water, slope mudstones with thin turbidite beds merge upward with prodelta mudstones and thin sandstones, which are truncated by delta‐front to mouth‐bar sandstones. The latter sandstones are then downcut by large‐scale, trough cross‐stratified coarse‐grained sandstones and conglomerates of distributary channel systems and along‐strike, amalgamated with cross‐bedded sandy units showing evidence of tidal reworking. Proximal–distal facies and architecture variability within a shelf‐edge deltaic succession demonstrates that distributary channel‐complexes become wider and deeper basinward, forming channelized river‐dominated distributary fairways separated by tidally reworked inter‐distributary sand belts at the shelf edge. Evidence from depositional‐dip oriented outcrops shows a lack of collapsed and slumped strata at the shelf edge, and that the coarse shelf‐edge distributary channel fills continue far down the deepwater slope, and conglomerates transform to become high‐density turbidites to mainly thick‐bedded, sand‐matrix‐supported debrites. The interplay between flood tides and river currents is interpreted to have primarily modulated the focusing of river drainages, and consequently coarse‐grained sediment transport, along preferential routes on the outer‐shelf to shelf‐edge and down onto the slope. This contribution documents a unique example of coarse‐grained (mostly conglomeratic) shelf‐edge delta systems, tying bed‐scale facies and architecture data to a seismic‐scale shelf‐margin morphology, thus providing outcrop analogue data for the characterization of shelf‐edge delta systems in the subsurface.

中文翻译：

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河流为主且受潮汐影响的陆缘三角洲系统：粗粒三角洲跨越早侏罗世陆架-斜坡折断并转变坡度，阿根廷内乌肯盆地的拉哈斯-洛斯莫莱斯地层

本文介绍了在阿根廷内乌肯盆地南部中下侏罗统拉哈斯和洛斯莫尔斯地层之间过渡形成的陆缘三角洲单元的三维相和构造变异，以及它们与最深层之间的地层关系。 -水坡通道系统。深水，倾斜的泥岩和薄的浊积岩床层与三角洲的泥岩和薄的砂岩向上合并，被三角洲前缘截断成口状的砂岩。后者的砂岩随后被大规模的槽状交叉分层的粗粒砂岩和分布通道系统和沿走向的砾岩冲切，并与交叉层状的砂岩单元合并，显示出潮汐返工的迹象。架子边缘三角洲演替过程中的近－远相和构造变化表明，分布河道复杂向盆地的方向越来越宽，形成了由河道支配的河道支配航道，这些支配航道被架子边缘的经过整修的分配间砂带隔开。沉积垂向露头的证据表明，在陆架边缘没有塌陷和塌陷的地层，并且粗陆架边缘的分流河道继续沿深水坡向下延伸，砾岩转变成高密度的浊度，主要是厚的浊度。砂状基质支撑的层状碎屑。潮汐和河流水流之间的相互作用被认为主要是调节了河流排水的集中度，并因此调节了粗粒沉积物的输送，沿外架到层架边缘的优先路线，然后下降到斜坡上。该文稿记录了一个粗粒（大多是砾岩状）的架子边缘三角洲系统的独特示例，将床规模相和建筑数据与地震规模的架子边缘形态联系在一起，从而提供了露头的模拟数据来表征架子边缘。地下的三角洲系统。