Ediacaran Cordilleran-type mountain ice sheets and their erosion effects

Decoding the Puzzle of Late Ediacaran Glaciation(s)

“…Paleomagnetic data from worldwide continents can not only confirm such a large-scale paleogeographic reorientation through the TPW, but also directly give the latitudes for the glacial deposits, because this new interpretation requires a mid-to-high-latitudedominated ice cover; (2) climatic numerical simulations. In Decoding the Puzzle of Late Ediacaran Glaciation(s) principle, large-scale continents shifting, or mountain buildup could affect the surficial system (Niu et al, 2024), simulations of climate would be an effective way to go, as worked on the Cryogenian Snowball Earth state (e.g., Cox et al, 2016). Also, this process is a good link between deep and shallow geodynamics to the geosphere, hydrosphere, and biosphere as pointed by Raub et al (2007), may also provide a new start to understand the coevolution of the Earth's system, including life and surficial environment on the eve of 'Cambrian Explosion', or it is already on the way (e.g., Wang et al, 2023a;Zhang et al, 2023;Rooney et al, 2020).…”

“…To achieve this goal, the nature of the glaciation itself needs to be understood first. Until now, 32 or more Ediacaran glacial deposits have been documented on almost all the existing continents (Niu et al, 2024;Wang et al, 2023a, b, c), showing a similar distribution pattern to the two Cryogenian (Sturtian and Marinoan) Snowball Earth glaciations if plotted in one single paleogeographic map (Figure 1; Niu et al, 2024;Li et al, 2013). But further compared to the Cryogenian Snowball Earth glaciations, the Late Ediacaran glaciation has some fundamentally different characteristics: (1) as shown in Figure 1, most glacial deposits are not stratigraphically overlain by the typical cap carbonate while it usually happened in the aftermath of a Snowball Earth glaciation and represented an abrupt climatic switch from extreme icehouse (global freezing) to greenhouse (global warming) condition (Hoffman et al, 2017); (2) unlike the Snowball Earth, not all the individual glaciations from different continents are in one similar age and can be broadly correlated with the well-known Gaskiers glaciation in the Avalonia of Canada, which has been precisely dated at ca.…”

“…Thus, two questions came out: (1) how to interpret the extensive glaciations, especially the 11 aftermath cap carbonates (Wang et al, 2023b, c) in a non-Snowball Earth condition, accordingly unraveling the mechanism of the Late Ediacaran glaciation? (2) how to understand the co-occurrence of <575 Ma Ediacaran life (including the Avalon and White Sea assemblages) and glaciations in either one or multiple episodes of the ice age (Niu et al, 2024;Retallack, 2022)? Previously, due to poorly direct age constraints on the glacial deposits and the paucity of reliable paleomagnetic poles from the Gondwana continents for a good paleogeographic map reconstruction, solution to these important questions is largely controversial and enigmatic.…”