Earth and Planetary Sciences Publications and Other Works
An Evaluation of the History of Aqueous Activity on Mars through a Survey of Select Hypothesized Martian Deltas and Paleolakes via the Analysis of Mineralogy, Morphology, and Thermophysical Properties
Abstract
Aqueous deposits are an essential key to understanding the geologic/climatic history of water on Mars. The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), the High Resolution Imaging Science Experiment (HiRISE), and the Thermal Emission Imaging System (THEMIS), have enabled studies of Martian fan deposits in unprecedented detail, including identification of aqueous minerals (such as phyllosilicates, carbonates, and sulfates) and aqueous morphologies in association with Martian fan deposits. In this study, twenty-six previously identified fan-shaped deposits (hypothesized as possible deltas) were examined for aqueous minerals in the beds and surrounding areas of the deposits. Six deposits have newly been identified as bearing aqueous minerals (primarily Fe/Mg-phyllosilicates) and are characterized herein with regards to mineralogy, morphology, and thermophysical properties. The results of our analyses suggest that at least four of these deposits are consistent with formation in a deltaic environment, but may not be exclusively diagnostic of formation via deltaic processes, as some of the minerals and morphologies present could also have been formed in other sedimentary environments, such as alluvial fans or alluvial fan-deltas. The results of this study are consistent with Mars once having hosted aqueous environments in which flowing and standing water was sustainable on the surface, allowing the formation of deltas on Mars.