January, 2008: Silicon Map
This gamma ray spectrometer map of the mid-latitude region of Mars is based on gamma rays from the element silicon. Silicon, with the chemical symbol Si, is one of the most abundant elements on the surface of both Mars and Earth, second only to oxygen. Regions of low silicon, shown in dark blue and violet, may be related to silicon-poor lava flows. Regions of high silicon, shown in red and yellow, may result from rocks that formed with higher silicon content or from weathering processes that concentrated silicon in these regions. The white sections at the top and bottom of the map represent regions of the planet where obtaining concentration values for silicon is more difficult due to large amounts of water ice in the soil. The locations of the five successful lander missions are marked: Viking 1 (VL1), Viking 2 (VL2), Pathfinder (PF), Spirit at Gusev (G), and Opportunity at Meridiani (M). More information about this map can be found in the recent article by Boynton, W. V., et al. (2007), Concentration of H, Si, Cl, K, Fe, and Th in the low- and mid-latitude regions of Mars . You may obtain full resolution versions of this and other elemental maps at http://grs.lpl.arizona.edu/specials/.