Mawrth Vallis Candidate Landing Site


One of the candidate landing sites for the Mars Science Laboratory is in the Mawrth region of Mars.  The candidate landing ellipse is located on highly cratered terrain with extensive bedrock outcrop.  Diverse hydrous minerals have been detected from orbit, providing strong motivation for sending a landed mission to this area.  However, models for the accumulation of bedrock in the area are poorly constrained.

To evaluate the physical characteristics of light-toned bedrock in Mawrth area, I am describing features from and mapping relationships on HiRISE images, anaglyphs, and DTMs in the context of CTX images. 

I have found that light-toned bedrock near the Mawrth candidate landing site is highly fractured and brecciated.  Several fracture patterns and breccia types are consistent with shock deformation due to impacts.  Very few areas near the landing ellipse have layers that are laterally continuous for more than 100 m.  This lack of continuity can be attributed to impact-induced disruption of layers as well as inhomogeneous rock accumulation.

A new depositional model is proposed for the effects of impact processes on accumulation of rock that is relevant to rock formation on early Mars.  Rocks that accumulated during the phase of martian history with frequent impacts should:  1) be heavily fractured; 2) show highly heterogeneous characteristics laterally and vertically; 3) lack laterally continuous stratification; 4) contain breccia as well as finer-grained units; and 5) be highly altered geochemically if water was available.  These characteristics are consistent with our current understanding of the Mawrth region.  Thus, it is likely that many of the characteristics of Mawrth light-toned bedrock were shaped by impact processes.

See videos of some of these relationships at CrustaMars on YouTube.


(Annotated HiRISE image of a small crater near the center of the Mawrth candidate landing ellipse as viewed in Crusta; imagery and topography courtesy of NASA/JPL/University of Arizona)