Origin and evolution of valleys on Martian volcanoes

Morphological analyses of six Martian volcanoes, Ceraunius Tholus, Hecates Tholus, Alba Patera, Hadriaca Patera, Apollinaris Patera, and Tyrrhena Patera, indicate that fluvial processes were the dominant influence in the initiation and subsequent development of many dissecting valleys. Lava processes and possibly volcanic density flows were also important as valley-forming processes. The presence of anomalously young fluvial valleys on Alba Patera indicates that fluvial valley activity did not entirely cease near the end of late heavy bombardment but rather persisted in isolated regions until mid to late Amazonian. -from Authors