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Lookup NU author(s): Professor Bethan DaviesORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2021 The Author(s)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.
Author(s): Vandyk TM, Kettler C, Davies BJ, Shields GA, Candy I, Le Heron DP
Publication type: Article
Publication status: Published
Journal: Precambrian Research
Year: 2021
Volume: 363
Print publication date: 01/09/2021
Online publication date: 17/08/2021
Acceptance date: 01/08/2021
Date deposited: 18/10/2023
ISSN (print): 0301-9268
ISSN (electronic): 1872-7433
Publisher: Elsevier B.V.
URL: https://doi.org/10.1016/j.precamres.2021.106345
DOI: 10.1016/j.precamres.2021.106345
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