“…Images revealed shield and dome volcanoes of the Tharsis and Elysium regions, extensive lava plains, and numerous other features of volcanic origin, including low-profile contructs, called patera, characterized by central craters and radial channels. Subsequently, data from the Viking Orbiters (Carr et al, 1977b) allowed mapping and characterization of the extent, timing, and styles of volcanism on Mars (Figure 1; Greeley andSpudis, 1978, 1981;Mouginis-Mark et al, 1992;Greeley et al, 2000). High resolution images (Malin et al, 1998) (Figure 1), information on surface compositions (McSween et al, 1998), and topographic data (Smith et al, 1998(Smith et al, , 1999a from the Mars Global Surveyor (MGS) permit comparison of Martian volcanism with theoretical analysis of the ascent and eruption of magma on Mars (e.g., Wilson and Head, 1994).…”