Evidence for a Thick Mantle of Volatile-rich Materials in the Utopia Basin, Mars, Based on Crater Depth/diameter Measurements:

Introduction: This study focuses on the depth/diameter (d/D) relationships of impact craters within Utopia Basin (25°N-70°N, 88°W-150°W), Mars. In order to search for spatial variations in the study area, d/D values for a total of 1,430 craters have been grouped by sub-regions based upon their similar d/D characteristics. This has revealed a significant difference in d/D relationship for craters in north central Utopia basin compared with other parts of the basin, and withother areas on Mars. Preliminary measurements have also been collected in four additional test areas (Acidalia, Sinai, Sirenum, and south of Argyre) for comparison purposes. The technique described by [1] was used to measure d/D for all craters (ranging from ~2 km to 66 km dia.) in the study area. The gridded 1/64° MOLA data set was used for these measurements. Two different types of d/D were measured for each crater, as follows: 1) the difference in elevation between the crater floor and the rim (dR/D), and 2) the difference in elevation between the surface surrounding the crater and the floor (ds/D).