GEOLOGIC MAPPING OF A PALEO-DUNE FIELD NEAR BARTH CRATER, MARS

Dune fields and aeolian activity are common on the surface of modern Mars and increasing evidence from the rock record indicates aeolian activity was equally common on ancient Mars. Transport pathways for aeolian sand can be interpreted from a range of flow indicators and dune morphologies on modern Mars, but interpreting ancient transport pathways requires a similar breadth of data that is either almost never preserved or hidden in subsurface rocks. Here, we describe an unusual terrain in the vicinity of the recently named Barth crater (7.4 deg. N, 25.6 deg. E) that preserves a lithified paleo-dune field. The terrain exhibits a texture of stacked crescentic forms that consistently open to the northwest. The features are confined by ridges and crater rims within the study area. Inverted stream channels in the area suggest water may have played a role in the preservation of the crescentic forms. The crescentic forms collectively span more than 150 km both inside and outside Barth crater and may provide evidence for a paleo-transport-pathway from south to north for ancient sand on Mars.