Bed thickness distributions on Mars: An orbital perspective

Studies on Earth show that sedimentary bed thickness and bed thickness distributions record information about the processes controlling sediment deposition. High-resolution digital terrain models (DTMs) such as those derived from the High Resolution Imaging Science Experiment (HiRISE) now provide the opportunity to quantify bed thickness properties on Mars over several orders of magnitude, down to the submeter scale. This study uses HiRISE DTMs and visible images to measure bed thickness distributions at 10 deposits on Mars, with the aim of determining whether statistical techniques can provide useful criteria for distinguishing sedimentary depositional processes. Basic statistics, including mean thickness and range, are examined, as are histograms, cumulative frequency plots, and log-log plots. Statistical tests interrogate these deposits for thinning or thickening upward trends and the presence of normal, lognormal, and exponential distributions. Although there are challenges associated with these methods, the statistical analysis of bed thickness, coupled with morphological and mineralogical interpretations, has the potential to be a powerful tool for characterizing and classifying sedimentary rocks on Mars. In particular, bed thickness statistics are particularly well suited for examining changes in sediment supply and accommodation within Martian sedimentary sequences.