Citation: K.L. Tanaka, J.A. Skinner, Jr., J.M. Dohm, R.P. Irwin, III, E.J. Kolb, C.M. Fortezzo,Thomas Platz, G.G. Michael, and T.M. Hare, 2014, Geologic Map of Mars, Scale 1:20,000,000, U.S. Geological Survey Scientific Investigations Map SIM 3292.
Shapefile (detail of original database)
Integrated Database of Planetary Features 