Electronic Thesis and Dissertation Repository

Degree

Master of Science

Program

Geology

Collaborative Specialization

Planetary Science and Exploration

Supervisor

Osinski, Gordon R

Abstract

Currently, Mars appears to be in a ‘frozen’ and ‘dry’ state, with the clear majority of the planet’s surface maintaining year-round sub-zero temperatures. However, the discovery of features consistent with landforms found in periglacial environments on Earth, suggests a climate history for Mars that may have involved freeze and thaw cycles. Such landforms include hummocky, polygonised, scalloped, and pitted terrains, as well as ice-rich deposits and gullies, along the mid- to high-latitude bands, typically with no lower than 20o N/S. The detection of near-surface and surface ice via the Phoenix lander, excavation of ice via recent impact cratering activity as monitored by High Resolution Imaging Science Experiment (HiRISE), Context Camera (CTX), and Compact Reconnaissance Imaging Spectrometer (CRISM), complemented by interpreted results from the SHAllow RADar (SHARAD) instrument, further unveil a landscape enriched in water/ice. Studies of the orbital behaviour of Mars have equally inferred that climate-forcing, triggered by cyclic shifts in the obliquity of Mars, controls the atmospheric stability of water-ice on the surface, allowing the mid- to high-latitudes to host a, so-called, periglacial environment. Still, there is much debate regarding just how ‘wet’ the paleoclimate of Mars has been, with concurrent water-related and ‘dry’ hypotheses having been put forth to explain the landscape evolution of the planet. We advocate that, considering the current limitations in studying Mars, geomorphological analysis is a reliable avenue in inferring the genetic nature of a landscape. As such, via a geomorphologic survey, we report on the landscape analysis of a region within Utopia Planitia. This region hosts a diverse abundance of potential periglacial features, including an intriguing ‘rimmed’ feature found within our study area. This feature, which we have dubbed ‘Decameter-scale Rimmed Depression’, serves as a valuable stratigraphic marker for rebuilding the geologic history of Utopia Planitia within the recent late Amazonian period, as it is both relatively young and potentially periglacial in nature. Ultimately, our aim is to unveil an additional piece to the periglacial ‘puzzle’ of Mars, via focusing on the prevalent process(es), responsible in shaping the landscape in question, and suggest a scenario for the late-Amazonian climate history, specific to Utopia Planitia.

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