Volcanic flows with very large areas characterize the Martian volcano Alba Patera. Photogeolic analysis indicates a change of eruptive style with time, from early flood lavas to relatively short, narrow, leveed summit flows during the dying phase of activity. Estimates of mass effusion rate and rheological properties derived from dimensional parameters confirm the view that the magmas involved were mafic, and indicate extremely high effusion rates (5--1610¿103m3 sec-1) for the earlier flows. The data substantiates the view that during the active life of Alba volcano mass eruption rates in the Tharsis region of Mars were significantly higher than in most analogous terrestrial provinces, but probably not as high as those for lunar mare basalts. ¿ American Geophysical Union 1987