Morphometry of a glacier-linked esker in NW Tempe Terra, Mars, and implications for sediment-discharge dynamics of subglacial drainage

Inverted channel belts and floodplain clays to the East of Tempe Terra, Mars: Implications for persistent fluvial activity on early Mars

“…Smectite-bearing clay minerals could be formed during this process. However, eskers normally have sharp or rounded crests [Butcher et al, 2020;Kargel and Storm, 1992;Pain et al, 2007], contrary to our observations and there is little evidence for glacial activities within the topographic depression. Also, the caprock trends consistently downhill while an esker origin commonly produces greater topographic undulations [Butcher et al, 2020].…”

Multiple sites of recent wet-based glaciation identified from eskers in western Tempe Terra, Mars

“…Sinuous ridges elsewhere in Tempe Terra have been interpreted as candidate eskers (Fig. 1B), including in an unnamed graben in northwest Tempe Terra, adjacent to our study area (Butcher et al, 2017(Butcher et al, , 2020. In Chukhung Crater, ~600 km southeast of our study area, sinuous ridges have been interpreted as eskers and/or pre-glacial fluvial features (Butcher et al, 2021).…”

“…Eskers are sedimentary ridges that are deposited by meltwater in subglacial tunnels (e.g., Shreve, 1985). Their identification in association with VFFs suggests that glacial meltwater has been produced by localized basal melting of those VFFs in the last 100s of Ma (Butcher et al, 2017(Butcher et al, , 2020(Butcher et al, , 2021Gallagher and Balme, 2015). The apparent scarcity of VFF-linked eskers elsewhere in Mars' mid-latitudes suggests that meltwater production was not driven solely by climate-induced warming, but also by local factors such as elevated geothermal heat flux and strain heating (Butcher et al, 2017;Gallagher and Balme, 2015).…”

Contextualizing lobate debris aprons and glacier-like forms on Mars with debris-covered glaciers on Earth

“…However, in this review we do not discuss the body of work devoted to understanding the role of meltwater in terrestrial debris-covered glacier evolution because the evidence for significant glacial meltwater on Mars is relatively limited, although we note that meltwater associated with subglacial conditions or impact craters may have affected the glacial landscape evolution in some regions on Mars (e.g. Bernhardt et al, 2013; Butcher et al, 2017, 2020; Fassett et al, 2014; Gallagher and Balme, 2015; Guidat et al, 2015). Glacier response is sensitive to the extent and flux of debris input and debris-cover thickness.…”

“…Furthermore, while there is morphological evidence for wet-based glaciation on Mars, the most identifiable landforms on the Martian surface are found in select locations and have been analyzed as part of local studies in the mid-latitudes (e.g. Butcher et al, 2017, 2020; Gallagher and Balme, 2015; Hubbard et al, 2011) and near the South Pole (e.g. Arnold et al, 2019; Sori and Bramson, 2019).…”