BRENT: Chemical analysis by NASA’s Mars rover Curiosity indicates that water made several repeat appearances to create the rich mineral veins at a site called “Garden City” in the lower part of Mount Sharp.
The veins form in places where fluids have move through fractured rocks, depositing minerals and leaving telltale chemical fingerprints on surrounding areas. Some of the mineral veins at Garden City protrude the equivalent of two finger widths above the now-eroded bedrock in which they formed.
The site was not accessible to Curiosity’s drill, but in March the rover zapped 17 targets with its ChemCam laser and discovered a diverse chemical stew.
“I think this has some of the most extreme chemistry that we’ve seen in a very localized area. There’s been other places where we’ve seen very strong chemistry, but in this kind of meter-square area, up until this point I don’t think we’ve seen anywhere with this much variability and this much unexpected chemistry,” Curiosity scientist Diana Blaney, with NASA’s Jet Propulsion Laboratory in Pasadena, Calif, told Discovery News.
Many of the veins contain rich deposits of calcium sulfate. Others are laced with magnesium sulfate or fluorine. Levels of iron vary.
The three-mile-high Mount Sharp rises from the floor of a huge impact basin that once held water. The Garden City veins were created after mud in the lake had hardened into rock and cracked.
