Abstract Sandy braided dryland rivers, deposited under arid to semi-arid conditions, constitute important clastic reservoirs worldwide whose reservoir quality reflects the effect of primary sediment properties on near-surface diagenetic processes. A literature review is presented of existing facies models, mainly based on geomorphological analysis of modern perennial braided rivers, which is further illustrated with own outcrop and subsurface examples of dryland river deposits in: (a) Argana Basin (Triassic, Morocco), (b) Iberian Meseta (Triassic, Central SE Spain), (c) Huesca Fluvial Fan (Miocene, Spain) and (d) Rotliegend hydrocarbon reservoirs in the Southern Permian Basin (The Netherlands). The facies models combined with the analyses of the rock record provide a comprehensive depositional framework where investigated for the influence of depositional characteristics, such as grain-size and sorting variations, interstitial clay distribution and composition and amount of intrabasinal components, on the extent and pathway of near-surface mechanical and chemical processes. The particular dryland setting is characterized by prolonged periods of inactivity and short, episodic periods of peak discharge which lead to the transport and deposition of poorly-sorted, clay-rich extra- and intraformational conglomeratic sediments upstream. Downstream, channels, mid-channel and bank attached bars develop with conspicuous anisotropic trough and tabular cross-stratified sandstones. The most common near-surface diagenetic processes that alter the textural properties of these deposits are the rapid decrease of porosity and permeability due to grain-rearrangements and mechanical compaction of mud intraclasts along with pervasive early carbonate cementation. The results of this study will help to better configure the boundary conditions (e.g., external versus local supply for carbonates cements) in state-of-the-art reservoir quality forward models for ancient dryland river sandstones, which are especially prominent in Devonian, Permian, Triassic and Jurassic reservoir settings.

中文翻译：

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旱地河流沉积物性质的沉积控制：对近地表成岩作用的影响

摘要 干旱至半干旱条件下沉积的沙质辫状旱地河流构成了世界范围内重要的碎屑岩储层，其储层质量反映了原生沉积物性质对近地表成岩过程的影响。对现有相模型进行了文献综述，主要基于现代多年生辫状河的地貌分析，并通过以下旱地河流沉积物的露头和地下实例进一步说明：(a) Argana 盆地（三叠纪，摩洛哥），(b ）伊比利亚梅塞塔（三叠纪，西班牙东南部中部），（c）韦斯卡河流扇（西班牙中新世）和（d）南二叠纪盆地（荷兰）的 Rotliegend 油气藏。相模型结合岩石记录的分析提供了一个综合的沉积框架，研究了沉积特征对范围和路径的影响，例如粒度和分选变化、间隙粘土分布和盆地内组分的组成和数量近地表机械和化学过程。特殊的旱地环境的特点是长时间的不活动和短暂的、间歇性的高峰排放期，这导致上游分选不良、富含粘土的地层外和地层内砾岩沉积物的运输和沉积。下游河道、河道中、岸边发育有明显的各向异性槽和板状交叉层理砂岩。改变这些沉积物结构特性的最常见的近地表成岩过程是由于颗粒重排和泥浆内碎屑的机械压实以及普遍的早期碳酸盐胶结作用导致孔隙度和渗透率迅速下降。这项研究的结果将有助于在最先进的古代旱地河流砂岩储层质量前向模型中更好地配置边界条件（例如，碳酸盐水泥的外部供应与本地供应），这在泥盆纪、二叠纪尤为突出、三叠纪和侏罗纪储层设置。