Faults and ridges - Historical development in Tempe Terra and Ulysses Patera regions of Mars

Tempe Terra and the area north of Ulysses Patera are selected to demonstrate the various stages of faulting and ridge development in local areas. This work is accomplished by using Viking photomosaics to determine crosscutting relations of structures as well as their morphology and trend orientations. Results show that from the Early Noachian through the Early Amazonian Epochs, at least eight episodes of faulting occurred at Tempe Terra and six at Ulysses Patera. Tectonic activity at Tempe Terra was expressed mainly by densely spaced faults along the northeast extension of the Tharsis rise; faulting culminated in the Middle and Late Noachian and was superseded by transverse fault systems from the Alba Patera region during the Hesperian. Ridge formation, however, was most active in the Early Hesperian. At Ulysses Patera, an early history of tectonism is recorded by complex arrays of faults in a relatively small area of Noachian rocks. 14 refs