The present paper focuses on the fluvial architecture and depositional facies model of the Late Cretaceous large sandy braided-river system of the Nubia Formation in the central Eastern Desert of Egypt. Six lithofacies types and two paleosol pedotypes (entisol and vertisol) are arranged in channel and overbank architectural elements that display first- to fifth-order bounding surfaces. Two distinctive fluvial architectural styles are recognized. The Fluvial architecture of the lower member identifies a low sinuous and energetic sandy braided river, in which the channels cover the entire of fluvial landforms with limited overbank areas. The suggested depositional model resembles the classic Platte-type braided river with its broad, low sinuosity streams, rich sand bedload and minor overbank sediments. Recurrent autogenic fining-upward cycles, rarely preserved overbank deposits, dominant entisol pedotype, prevailing trough cross-bedded sandstones, sporadic to absent planar cross-bedded sandstone, and dominant downstream accretion also imply perennial, sandy braided rivers. By contrast, the fluvial architecture of the upper member is characterized by fining-upward cycles, downstream and lateral accretion elements, and commonly preserved overbank deposits (overprinted by the mature vertisol pedotype). This architecture style is ascribed to a perennial sandy braided river characterized by sinuous energetic streams and laterally developed overbank areas, similar to the modern South Saskatchewan River in Canada. The fluvial depositional system and sequences in the Nubia Formation are strongly controlled by Late Cretaceous base-level fluctuations and tectonic pulses of the Laramide Orogeny.

本文重点研究埃及东部沙漠中部努比亚组晚白垩世大型砂质辫状河系统的河流构造和沉积相模型。六种岩相类型和两种古土壤类型（对映体和对映体）布置在河道和岸上建筑元素中，这些建筑元素显示出一阶到五阶边界表面。人们认识到两种独特的河流建筑风格。下半部的河流结构识别出一条低弯且充满活力的沙质编织河，其中的河道覆盖了整个河床地貌，且河床覆盖区域有限。建议的沉积模型类似于经典的普拉特型辫状河，具有宽阔，低曲率的河流，丰富的沙床和少量的过高沉积物。反复的自发性精炼向上循环，极少保存的岸上沉积物，占优势的溶胶溶胶型，占主导地位的槽状交叉层砂岩，零星至不存在的平面交叉层砂岩，以及占主导地位的下游增生也意味着多年生的沙状辫状河。相比之下，上部构件的河流构造的特征是向上上升的旋回，下游和横向的增生要素，以及通常保存的堤岸沉积物（由成熟的Vertisol原型印刷而成）。这种建筑风格归因于多年生的沙状辫状河，其特征是蜿蜒的高能流和侧向发达的河岸地区，类似于加拿大的现代南萨斯喀彻温河。努比亚组的河流相沉积体系和层序受到晚白垩世基面涨落和拉拉米德造山带的构造脉冲的强烈控制。