Reassessing classic evidence for warm-based Cryogenian ice on the western Laurentian margin: The “striated pavement” of the Mineral Fork Formation, USA

This dataset supports the following manuscript, available free of charge at https://www.sciencedirect.com/science/article/pii/S0301926821002734 : Vandyk, T.M., Kettler, C., Davies, B.J., Shields, G.A., Candy, I., Le Heron, D.P., 2021. Reassessing classic evidence for warm-based Cryogenian ice on the western Laurentian margin: The “striated pavement” of the Mineral Fork Formation, USA. Precambrian Research 363, 106345. https://doi.org/10.1016/j.precamres.2021.106345 Contents 1. Higher resolution versions of figures and supplementary figures. Please see https://doi.org/10.1016/j.precamres.2021.106345 for full descriptions of figures and supplementary figures. 2. Digital Elevation Model of "pavement": DEM S1: GeoTiff Digital Elevation Model of “pavement” used in Fig. 2; Spatial reference: NAD 1983 - UTM Zone 12N (EPSG::26912). 3. Movie files. Movie S1 and Movie S2 of the "pavement" and Mill B North Fork valley hosting the "pavement". Abstract Determining the extent and nature of ancient glacial deposits is fundamental to understanding Earth’s climate in the Cryogenian Period. Although the detailed study of sedimentary facies has allowed significant insights, it typically fails to produce high confidence interpretations for the past position of grounded ice, its thermal regime and flow direction, which are of fundamental importance to any glaciological reconstruction. When correctly identified, Cryogenian subglacially striated surfaces (pavements) unequivocally indicate grounded ice, a warm-based thermal regime and flow direction. However, they are globally rare and open to misinterpretation. Despite a discontinuous belt of Cryogenian strata, stretching thousands of kilometres from Alaska to California, the only purported Cryogenian pavements from the North American continent or the western margin of the Laurentian palaeocontinent occur in the Big Cottonwood Canyon area, Utah. We critically reappraise the only uncontested pavement from this area, presenting a detailed description derived from new high resolution photogrammetry and traditional field observations. These suggest that the purported pavement is unlikely to be a Cryogenian feature, but is instead a recent erosional phenomenon consistent with other structurally controlled features within the surrounding modern landscape. Our reinterpretation questions whether grounded Cryogenian ice reached the Utah – Idaho region and whether the lower reaches of the Mineral Fork Formation record glacially influenced deposition or non-glacial, rift-related sedimentation that transitions upwards into glacial conditions. Acknowledgements This work was supported by the Natural Environment Research Council [grant number NE/L002485/1] and awards to TMV from the International Association of Sedimentologists, the British Society for Geomorphology and Society for Sedimentary Geology (SEPM). We are most grateful to 3 anonymous reviewers, Marie Busfield, Nicholas Eyles and Maarten Krabbendam.

本数据集支持以下研究论文，可通过https://www.sciencedirect.com/science/article/pii/S0301926821002734免费获取：Vandyk, T.M.、Kettler, C.、Davies, B.J.、Shields, G.A.、Candy, I.、Le Heron, D.P.，2021年。《重新评估劳伦古大陆西缘成冰纪（Cryogenian Period）暖基冰川的经典证据：美国矿物福克组的"擦痕面"》，刊载于《前寒武纪研究》（Precambrian Research）第363卷，文章编号106345，DOI：https://doi.org/10.1016/j.precamres.2021.106345。

数据集内容：
1. 高清版图件及补充图件。图件与补充图件的完整说明请见https://doi.org/10.1016/j.precamres.2021.106345。
2. "擦痕面"数字高程模型（Digital Elevation Model, DEM）：DEM S1为图2所用"擦痕面"的GeoTiff格式数字高程模型，空间参考系为NAD 1983 - UTM 12N带（EPSG::26912）。
3. 视频文件。包含与"擦痕面"及其赋存的米尔河北支河谷相关的视频S1与视频S2。

摘要
确定古冰川沉积的分布与特征，是理解成冰纪地球气候的核心基础。尽管对沉积相的精细研究已取得诸多重要认识，但这类研究通常难以对冰床的古位置、热状态及流动方向做出高置信度的解释——而这些参数对任何冰川学重建而言均至关重要。若能准确识别，成冰纪冰下擦痕面（striated pavement）可明确指示冰床存在、暖基热状态及冰川流动方向，但这类遗迹在全球范围内极为稀少，且易被误释。尽管从阿拉斯加到加州绵延数千公里的地带断续分布有成冰纪地层，但北美大陆或劳伦古大陆西缘仅有的疑似成冰纪擦痕面发现于美国犹他州的大卡顿伍德峡谷区域。本文对该区域唯一一处无争议的擦痕面进行了批判性重新评估，结合新的高精度摄影测量数据与传统野外观测开展了详细描述。研究结果表明，该疑似擦痕面并非成冰纪遗迹，而是近期的侵蚀现象，与周边现代地貌中其他受构造控制的特征一致。本次重新解读对两个核心科学问题提出了质疑：一是成冰纪冰床是否抵达犹他-爱达荷地区；二是矿物福克组下段记录的究竟是受冰川作用影响的沉积，还是向上过渡为冰川环境的非冰川裂谷相关沉积。

致谢
本研究得到了自然环境研究理事会（资助编号NE/L002485/1）以及国际沉积学家协会、英国地貌学会与沉积地质学会（SEPM）授予TMV的奖项支持。我们衷心感谢三位匿名审稿人、Marie Busfield、Nicholas Eyles及Maarten Krabbendam。