Thin tidal estuarine deposits of the Naturita Formation (0–23 m) of the San Rafael Swell record the initial flooding of the Cretaceous Western Interior Seaway, Utah, and capture the transition from inland fluvial systems to fully marine conditions over a time period of 5 My or less. A tide-dominated estuarine environment is favored due to the combined presence of mud and/or carbonaceous drapes on ripples and dunes, bidirectional flow indicators, sigmoidal cross-stratification, herring-bone cross-stratification, and bimodal paleocurrent measurements. Facies associations are arranged in a predictable manner. Locally at the base of the Naturita Formation, tidally influenced fluvial channel deposits are present. These are overlain by tidal bars, including subtidal bars and intertidal point bars. Overlying the tidal bars are sand-flat and mud-flat deposits as well as bedded coal and carbonaceous mudstone that represents a supratidal setting in the estuary. The Formation can be capped by a thin transgressive lag composed of shell debris, and/or pebbles, that marks the final transition into the fully marine Tununk Shale Member of the overlying Mancos Shale.Lateral relationships between estuaries and adjacent paleohighs shed light on the influence of foreland-basin tectonics on the location and preservation of tide-dominated estuaries. Estuarine and shoreface deposits are absent along the eastern flank of the San Rafael Swell and eastward for more than 80 km. This zone of nondeposition or erosion is coincident with the location of the forebulge in the developing foreland basin, implying that growth of the forebulge prohibited the development of, or enhanced the later erosion of, estuarine deposits. Conversely, enhanced accommodation in the transition into the foredeep depozone allow the preservation of tide-dominated estuarine deposits along the western flank of the San Rafael Swell. Additionally, the possibility of a pre-Laramide tectonic history for the San Rafael Swell is indicated by a distinct lack of Naturita Formation deposits in an area that is coincident with the modern-day axis of the anticline.Overall, the Naturita records the initial flooding of the Western Interior Seaway in the San Rafael Swell region and provides an excellent case study of the deposits that are laid down in a transgressive system that passes from coastal-plain to offshore deposits.

中文翻译：

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海侵性Naturita组（达科他砂岩）的潮河口沉积物：美国犹他州圣拉斐尔·斯维尔

San Rafael Swell的Naturita组（0-23 m）潮汐河口薄层沉积记录了犹他州白垩纪西部内陆海道的初始洪水，并记录了从内陆河流系统到完全海洋条件的过渡，历时5年。我的或更少。潮汐主导的河口环境是有利的，这是因为在波纹和沙丘上存在泥浆和/或碳质垂布，双向流量指示符，S形交叉分层，人字形交叉分层和双峰古电流测量的结果。相关联以可预测的方式排列。在Naturita组底部局部，存在潮汐影响的河道沉积物。这些被潮汐条覆盖，包括潮下条和潮间点条。潮汐坝上方是砂滩和泥滩沉积物，以及代表河口上方环境的层状煤和碳质泥岩。该地层可以被由壳屑和/或卵石组成的海侵稀薄层所覆盖，这标志着其最终过渡到上覆Mancos页岩的全海洋Tununk页岩中。河口与邻近古隆起之间的横向关系揭示了其影响。盆地构造对潮汐河口的位置和保护的影响。San Rafael Swell的东部侧面和向东超过80公里处没有河口和岸面沉积物。不沉积或侵蚀的区域与前陆盆地发育中前隆的位置重合，暗示前缘的增长阻止了河床沉积物的发展，或加剧了河床沉积物的侵蚀。相反，在过渡到前深层depozone的过程中增加的适应性，可以保留沿圣拉斐尔涌浪西翼的潮汐为主的河口沉积物。此外，圣拉斐尔隆起发生拉拉酰胺前构造历史的可能性由与背斜现代轴线重合的地区明显缺乏Naturita形成沉积物来表明。总体而言，Naturita记录了初始洪水是San Rafael Swell地区的Western Interior Seaway的一部分，它为从沿海平原到近海沉积物的海侵体系中沉积的沉积物提供了出色的案例研究。相反，在过渡到前深层depozone的过程中增加的适应性，可以保留沿圣拉斐尔涌浪西翼的潮汐为主的河口沉积物。此外，圣拉斐尔隆起发生拉拉酰胺前构造历史的可能性由与背斜现代轴线重合的地区明显缺乏Naturita形成沉积物来表明。总体而言，Naturita记录了初始洪水是San Rafael Swell地区的Western Interior Seaway的一部分，它为从沿海平原到近海沉积物的海侵体系中沉积的沉积物提供了出色的案例研究。相反，在过渡到前深层depozone的过程中增加的适应性，可以保留沿圣拉斐尔涌浪西翼的潮汐为主的河口沉积物。此外，圣拉斐尔隆起发生拉拉酰胺前构造历史的可能性由与背斜现代轴线重合的地区明显缺乏Naturita形成沉积物来表明。总体而言，Naturita记录了初始洪水是San Rafael Swell地区的Western Interior Seaway的一部分，它为从沿海平原到近海沉积物的海侵体系中沉积的沉积物提供了出色的案例研究。过渡到前深部depozone的过程中增强了的容纳性，可以保留沿圣拉斐尔涌浪西翼的潮汐河床沉积物。此外，圣拉斐尔隆起发生拉拉酰胺前构造历史的可能性由与背斜现代轴线重合的地区明显缺乏Naturita形成沉积物来表明。总体而言，Naturita记录了初始洪水是San Rafael Swell地区的Western Interior Seaway的一部分，它为从沿海平原到近海沉积物的海侵体系中沉积的沉积物提供了出色的案例研究。过渡到前深部depozone的过程中增强了的容纳性，可以保留沿圣拉斐尔涌浪西翼的潮汐河床沉积物。此外，圣拉斐尔隆起发生拉拉酰胺前构造历史的可能性由与背斜现代轴线重合的地区明显缺乏Naturita形成沉积物来表明。总体而言，Naturita记录了初始洪水是San Rafael Swell地区的Western Interior Seaway的一部分，它为从沿海平原到近海沉积物的海侵体系中沉积的沉积物提供了出色的案例研究。