Chronology and global distribution of fault and ridge systems on Mars

Paleotectonic maps are presented showing fault and ridge systems on Mars as they existed during successive geologic periods: the Noachian, Hesperian, and Amazonian Periods, and their eight epoch subdivisions. The paleotectonic maps for the western, eastern, and polar regions were compiled at 1:15,000,000 scale and photographically reduced. Results show that most major fault systems are associated wiht large volcanic centers in the western equatorial region of Mars and that, probably, both faulting and volcanism decreased with time but included a pulse of renewed activity during the Early Hesperian.