Eroded Crater at Mawrth: at least 2 generations of fill.

Latitude/longitude:24° 2'20"N, 18°56'20"W(previously proposed but with different rationale)

Rationale:Evaluation of layering in bedrock vs layering due to erosion of recent crater fill

Morphology and Mineralogy: Bench in a crater and discontinuous dark bands in crater wall. Within Fe/Mg-smectite unit, with mafic dunes and recent crater fill.

What will the rover specifically do?Evaluate the structure of bedrock, specifically whether bedding or fracturing creates roughly horizontal bands in the crater wall. Also evaluate the origin of the topographic bench in the crater wall.

From HiRISE image ESP_011884_2045 draped on a HiRISE-derived DTM with 5 m contour interval show in yellow. The width of the yellow contours is inversely proportional to local slope. A nearly continuous bench in a small crater cuts rapidly up the crater wall to the west (mapped in red). The current fill level of the crater is similarly slopes (mapped in green dashes). The interaction of the bench with topography would define apparent dips if the bench represented a layer; all apparent dips project inward into the crater (white dip symbols). The slope of the crater substantially decreases above this bench on the east and northeast sides. These relationships suggest that the bench may represent a paleofill level for the crater.

Next slide

20 m

All images show the same area from HiRISE image ESP_011884_2045, which is draped on a HiRISE-derived DTM for images on the right, with 5 m contour interval show in yellow in B. The width of the yellow contours is inversely proportional to local slope. The star marks the same place in A and B. A) Sparse layering is present in the upper wall of the crater (mapped in red), but the layers are not laterally continuous. B) Same area as A, viewed obliquely. “Layers” do not project through topography, and separately mapped features can not represent through- going planes.