Lily S Pfeifer, University of Oklahoma Norman Campus, Norman, OK, United States, Gerilyn S Soreghan, Univ of Oklahoma, Norman, OK, United States, Linda A Hinnov, George Mason University Fairfax, Atmospheric, Oceanic, and Earth Sciences, Fairfax, VA, United States and Stephane Pochat, LPGN Laboratoire de Planétologie et Géodynamique de Nantes, Nantes Cedex 03, France