Investigation of the Global Escarpment, Including the Fretted Terrain, in the Martian Northern Hemisphere

Abstract

The global escarpment and associated fretted terrain are located in the Martian northern hemisphere. Two competing hypothesis presently in play explain the origin of Mars’ global escarpment. These hypotheses involve endogenic and exogenic processes and both could help explain the extreme topographic difference between the southern highlands and the northern lowlands. The focus of this study, the fretted terrain area of the global escarpment, is a transition zone of mesa-like features located directly north of the global escarpment. With the use of digital imagery analysis, georeferencing of existing maps, and the interpretation of current models, the most plausible origin of the escarpment proposed herein would be an exogenic process, namely a single, mega-scale impact shortly after formation of the planet. The main lines of evidence supporting this favored hypothesis are the modeled elliptical shaped basin, similarities between crustal thickness and topographic elevations, mineralogy, and the orientation and size distribution of the northern fretted terrain.