Acidalia Mena, Mars: A key region to test the ocean hypothesis

• Applicant: Professor Dr. Harald Hiesinger
• Subject Area: Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography ; Palaeontology
• Term: from 2018 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 413241974

The primary goal of our study is to geologically map the Acidalia Mensa region in the northern hemisphere of Mars at a scale of 1:200,000. The investigation will mostly rely on data of the THermal Emission Imaging Spectrometer (THEMIS) with a pixel scale of 100 m per pixel, augmented by data of the HiRISE, CTX, and HRSC cameras, as well as topography data of the MOLA laser altimeter. Acidalia Mensa is a topographically high-standing terrain north of the proposed shoreline of a putative former ocean on Mars. On the basis of our new geologic map, we propose to vigorously test the ocean hypothesis. The significantly improved quality of available modern imaging and topography data will allow us to geologically map the area in unprecedented detail, which will significantly increase our understanding of the regional geology as well as the existence and evolution of the putative ocean. On the basis of our geologic map we will select key areas for further high-resolution studies. We expect new insights into the geology and structure of the study area, which will allow us to understand its history and evolution. Besides generating a new geologic map, we propose to derive absolute model ages of the map units, decipher the stratigraphy of the area, calculate thermal inertias to estimate grain size distributions, and to perform morphometric measurements of relevant surface features. Results of these investigations, in concert with the geologic map, will be used to test the ocean hypothesis. Some key scientific questions of our study include: 1. What are the building blocks of Acidalia Mensa and what is their relationship to the surrounding Vastitas Borealis Formation? 2. Is there a genetic link between the Acidalia Mensa region and the southern highlands? 3. Is there evidence for a former north-polar ocean? 4. Was Acidalia Mensa surrounded by the putative ocean or did the ocean cover the study region? 5. How old is the Acidalia Mensa plateau and what is its stratigraphic relationship to the surrounding terrain? 6. Given the subdued morphology of impact craters, how much material has been removed from the Acidalia Mensa plateau?

• DFG Programme: Research Grants