NASA’s Mars rover Curiosity analyzed several rock samples from three different locations in the lower regions of Mount Sharp.

The rover has discovered a two-tone vein of unique mineral compositions. There were also prominent veins that showed the mountains layers, revealing different stages of weathering.

The two toned minerals were found in ridges along a site called ‘Garden City’ where bedrock has eroded and exposed these veins. Garden City sits 39 feet above the lower edge of the Pahrump Hills outcrop, which is part of the basal layer of the 3-mile-high Mount Sharp.

Linda Kah, Curiosity science team member of the University of Tennessee's said, “Some of them look like ice-cream sandwiches: dark on both edges and white in the middle. These materials tell us about secondary fluids that were transported through the region after the host rock formed”.

Kah said that on Earth, such mineral deposits are often associated with salty water. However, the dark deposits were somewhat unexpected.

The formation of the mineral veins found in Garden City took place when fluids seeped through the cracks in the rocks. The fluids deposited minerals that changed the rock's chemical structure inside the cracks and fractures gave it the appearance it has today.

The Curiosity team is planning to learn more about the time line of how these rocks and veins were formed. It is also trying to get clues about the chemical composition of the fluids that changed them and moved them along the terrain in Garden City.

The area was found to be covered in dried mud that hardened before the fractures of the mineral veins formed. NASA officials wrote that the mud that formed lake-bed mudstones were examined by Curiosity near its 2012 landing site. After reaching Mount Sharp, they must have dried and hardened before the fractures formed.