Namurian (Carboniferous) eustatic fluctuations drove the incision and backfill of shelf‐crossing valley systems located in humid subequatorial regions, which are now preserved in successions of the United Kingdom and Ireland. The infills of these valleys archive the record of palaeoriver systems whose environmental, hydrological and palaeogeographic characteristics remain unclear. A synthesis of sedimentological data from fluvial strata of 18 Namurian incised‐valley fills in the United Kingdom and Ireland is undertaken to elucidate the nature of their formative river systems and to refine regional palaeogeographic reconstructions. Quantitative analyses are performed of facies proportions, of geometries of incised‐valley fills and related architectural elements, and of the thickness of dune‐scale sets of cross‐strata. Reconstruction of the size of the drainage areas that fed these valleys is attempted based on two integrative approaches: flow‐depth estimations from dune‐scale cross‐set thickness statistics and scaling relationships of incised‐valley fill dimensions derived from late‐Quaternary examples. The facies organization of these incised‐valley fills suggests that their formative palaeorivers were perennial and experienced generally low discharge variability, consistent with their climatic context; however, observations of characteristically low variability in cross‐set thickness might reflect rapid flood recession, perhaps in relation to sub‐catchments experiencing seasonal rainfall. Variations in facies characteristics, including inferences of flow regime and cross‐set thickness distributions, might reflect the control of catchment size on river hydrology, the degree to which is considered in light of data from modern rivers. Palaeohydrological reconstructions indicate that depth estimations from cross‐set thickness contrast with observations of barform and channel‐fill thickness, and projected thalweg depths exceed the depth of some valley fills. Limitations in data and interpretations and high bedform preservation are recognized as possible causes. With consideration of uncertainties in the inference of catchment size, the palaeogeography of the valley systems has been tentatively reconstructed by integrating existing provenance and sedimentological data. The approaches illustrated in this work can be replicated to the study of palaeohydrological characteristics and palaeogeographic reconstructions of incised‐valley fills globally and through geological time.

中文翻译：

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下切谷填埋系统的古水文特征和古地理重建：来自英国和爱尔兰的纳穆里亚演替的见解

Namurian (石炭纪) eustatic 波动驱动了位于潮湿亚赤道地区的跨大陆架山谷系统的切割和回填，这些系统现在在英国和爱尔兰的继承中得以保存。这些山谷的填充物记录了古生物系统的环境、水文和古地理特征尚不清楚。对来自英国和爱尔兰的 18 个 Namurian 切谷填充的河流地层的沉积学数据进行综合，以阐明其形成的河流系统的性质并完善区域古地理重建。对相比例、下凹谷填充物和相关建筑元素的几何形状以及沙丘规模的跨地层厚度进行了定量分析。基于两种综合方法尝试重建为这些山谷提供水源的流域大小：根据沙丘尺度交叉集厚度统计数据和从晚第四纪实例得出的下切谷填充尺寸的比例关系估计流深。这些切谷充填物的相组织表明它们的形成古生物是多年生的，并且经历了普遍较低的流量变化，与它们的气候背景一致；然而，对交叉集厚度特征性低变异性的观察可能反映了洪水的快速衰退，这可能与经历季节性降雨的子流域有关。相特征的变化，包括对流态和交叉集厚度分布的推断，可能反映了流域大小对河流水文的控制，其程度是根据现代河流的数据考虑的。古水文重建表明，交叉集厚度的深度估计与条形和通道填充厚度的观察结果形成对比，并且预测的 thalweg 深度超过了一些山谷填充的深度。数据和解释的局限性以及高床型保存被认为是可能的原因。考虑到流域大小推断的不确定性，整合现有物源和沉积学数据，初步重建了河谷系统的古地理。