Voluminous volcanism on early Mars revealed in Valles Marineris.

Displays and describes images from the Mars Orbiter Camera, an instrument on the Mars Global Surveyor space probe that orbits Mars, and discusses processes that shaped the Martian surface. Evidence for ubiquitous, fine-scale layering within the Valles Marineris canyon; Unprecedented observations of detailed wall structures; Question of whether the origin for the layering is volcanic or sedimentary.