The assessment of the radiation environment on Mars is of fundamental importance for estimating the potential for (past and present) habitability. Here, we present a Monte Carlo particle transport study of the radiation environment and doses at Oxia Planum, the landing site of the next ESA mission ExoMars 2020, and the previously considered Mawrth Vallis site, for: 1) an average soil composition as inferred from Mars Odyssey Gamma-Ray Spectrometer/GRS data, and 2) different mineralogical associations as in recently reported weathering profiles, given by a) Al-rich clays, b) Fe/Mg-rich clays, and c) each of them in combination with carbonates.