Archive September 2009
The geology of the Thaumasia region on Mars includes a wide array of rock materials, depositional and erosional landforms, and tectonic structures. The region is dominated by the Thaumasia plateau, which is about 2,900 km across and rises over 4 km above the surrounding terrain. The plateau includes central high lava plains ringed by highly deformed highlands; it may comprise the ancestral center of Tharsis tectonism. The extensive structural deformation of the region, which is without parallel on Mars in both complexity and diversity, occurred largely throughout the Noachian and Hesperian periods (about 4 billion years ago). The deformation produced small and large extensional and contractional structures that resulted from stresses related to the formation of Tharsis, from magmatic-driven uplifts, such as at Syria Planum and central Valles Marineris, and from the Argyre impact. In addition, volcanic, eolian, and fluvial processes have highly modified the older surfaces in this region.
An escarpment in the center of this picture is at the south extension of the end of Claritas Fossae. The fractures are roughly radial to the Tharsis bulge and cut mostly old cratered terrain. Crater counts indicate that most of the fractures are older than the corresponding fractures north of the Tharsis bulge.
Mosaic of the Viking 1 Orbiter images f057a04 to f057a13, taken on August 17, 1976. North is at approximately the eleven o’clock position.
Image Credit: NASA/JPL/Arizona State University/Mosaic by astroarts.org
This Viking 2 Orbiter image (f176b02), taken on February 17, 1977, shows a large dust storm over the Thaumasia region on Mars. This large disturbance soon grew into the first global dust storm observed by the Viking Orbiters.
The image covers a region of nearly 1,400 km. North is at approximately the one o’clock position.
Image Credit: NASA/JPL/Arizona State University/astroarts.orgoff