EGU23-15877
https://doi.org/10.5194/egusphere-egu23-15877
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Large Area Glacier-Like Forms on Mars: Insights from Impact Crater Morphologies and Crater Retention Ages

Graham Driver1, Mohamed Ramy El-Maarry2, Bryn Hubbard3, and Stephen Brough4
Graham Driver et al.
  • 1Birkbeck University of London, Department of Earth and Planetary Sciences, London, UK (grahamdriver86@gmail.com)
  • 2Space and Planetary Science Center, and Department of Earth Sciences, Khalifa University, Abu Dhabi, UAE
  • 3Department of Geography and Earth Sciences, Aberystwyth University, Wales, UK
  • 4School of Environmental Science, University of Liverpool, UK

Ice-rich landforms known as Viscos-Flow Features (VFFs) are common in Mars’ mid-latitudes. Glacier-Like Forms (GLFs) are a distinct sub-category of VFFs and appear morphologically similar to terrestrial valley glaciers or rock glaciers. GLFs are thought to be the result of the redistribution of water ice from the Martian poles during periods of high obliquity (>35o) and the Last Martian Glacial Maximum (LMGM), which ended ~5 Myr. Numerous distinct impact crater morphologies have been observed on these ice-rich terrains. Research has suggested that this variation results from interactions between landform lithologies and surface evolution through depositional and erosional processes. We investigated impact crater quantities and morphologies on 100 GLFs with large surface areas, with the aim of determining Crater Retention Ages (CRAs) for the landforms and exploring the relationships between crater morphology variation and relative surface ages.

Our results show GLF ages vary across Mars, with various surface retention ages and crater morphologies populations. There are populations of GLFs with young CRAs (<20 Ma), particularly in the southern hemisphere, suggesting recent glaciation could have been more favourable in the southern mid-latitudes. Our results suggest several scenarios for GLFs across Mars. (1) That some GLFs have the potential to be very young, having perhaps formed in the last few million years during the LMGM. (2) That some GLFs may have formed before the LMGM (>20Ma) but have high resurfacing rates, partially removing their impact records. (3) That some GLFs formed long before the LMGM and have medium to very low resurfacing rates. These GLFs have surfaces with greater quantities and morphological variation of craters. Consequently, they also appear to record more resurfacing events and have more comprehensive CRA ranges. The low resurfacing rates suggest that these GLFs have not been in favourable depositional environments for an extended period and are possibly in low erosional settings. The study hints that while high Martian obliquity periods can favour glaciation, material accumulation, and resurfacing events, this occurs within local geographical constraints and that not all periods of glaciation are favourable to all GLFs across Mars.

How to cite: Driver, G., El-Maarry, M. R., Hubbard, B., and Brough, S.: Large Area Glacier-Like Forms on Mars: Insights from Impact Crater Morphologies and Crater Retention Ages, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-15877, https://doi.org/10.5194/egusphere-egu23-15877, 2023.