Mawrth Candidate Landing Site (Dawn Sumner, July 27, 2010) Site Context Mineral Stratigraphy Models for Clay Mineral Accumulation Implications for Biosignature Formation & Preservation

Mawrth Site is in Far Western Arabia Terra Approximate outline of “Arabia Terra” is shown. Interpretation of exact “boundaries” may vary depending on who you ask.

Oyama Crater & Mawrth Vallis

Landing Ellipse Oyama Crater

Michalski et al. 2010

Loizeau et al. 2010 Blue ~ Al-clay mineral detections Orange ~ Fe, Mg-clay mineral detections Loizeau et al. 2010

Models for Clay Minerals (not mutually exclusive) Alteration of Bedrock (igneous or other) “Soils”, hydrothermal, or water table Alteration as Rock Accumulated Many “soils” Alteration of hydrous pyroclasitcs Alteration associated with impacts Sedimentary Accumulation of Clay Minerals Fluvial, lacustrine, unknown

Bedrock Alteration Michalski & Noe Dobrea, 2007 Issues: Variable Alteration/Mineralogy Depth of Alteration Extent of Chemical Leaching Origin of Bedrock

Alteration During Accumulation Issues: Consistency of Mineral Stratigraphy Variations in Mineralogy with Depth Pervasiveness of Alteration Sumner, in prep.

(no published images of models to my knowledge) Deposition of Clays Issues: No Reported Sedimentary Geometries No Basin Margins to Confine Flow Only Rare Channels, Post Deposition of Light Toned Units Compositionally Defined Layers “Drape” Topography (no published images of models to my knowledge)

Biosignature Formation and Preservation (Summons et al., in review)