NASA's Curiosity rover has analyzed numerous rock samples from three different locations in the lower regions of Mount Sharp that reveal unique mineral compositions. Along with the discovery of the different minerals, there were also prominent veins that show the mountains layers, revealing different stages of weathering. These two toned minerals were found in ridges along a site called "Garden City" where bedrock has eroded and exposed these veins.
"Some of them look like ice-cream sandwiches: dark on both edges and white in the middle," Curiosity science team member of the University of Tennessee's, Linda Kah said in a statement. "These materials tell us about secondary fluids that were transported through the region after the host rock formed."
She says that these materials are evidence of how secondary fluids were transported around the region after the formation of the host rock. The mineral veins found in Garden City were formed when fluids seeped through the cracks in the rocks, depositing minerals that changed the rock's chemical structure inside the cracks and fractures giving it the appearance it has today.
The team controlling Curiosity is now planning to learn more about the time line of how these rocks and veins were formed, including the chemical composition of the fluids that changed them and moved them along the terrain in Garden City. Researchers also found the area is now covered in dried mud that hardened before the fractures of the mineral veins formed. There is evidence that earlier fluid flowed over the dark material within the white veins that occurred after the formation of the cracks.
"Mud that formed lake-bed mudstones Curiosity examined near its 2012 landing site and after reaching Mount Sharp must have dried and hardened before the fractures formed," NASA officials wrote in a statement. "The dark material that lines the fracture walls reflects an earlier episode of fluid flow than the white, calcium-sulfate-rich veins do, although both flows occurred after the cracks formed."
Garden City is located 39 feet above the Pahrump Hills' bottom edge where a bedrock outcrop formed in Mount Sharp's basal layer in the center of the Gale Crater. Curiosity spent six months analyzing 33 feet of Pahrump Hills' elevation to measure and learn more about the rock chemistry of the region while also searching for signs of microbial life in the area.
