This view from the Mast Camera (Mastcam) on NASA’s Curiosity Mars rover shows a network of two-tone mineral veins at an area called “Garden City” on lower Mount Sharp.
The veins combine light and dark material. The veins at this site jut to heights of up to about 2.5 inches (6 centimeters) above the surrounding rock, and their widths range up to about 1.5 inches (4 centimeters). Figure 1 includes a 30-centimeter scale bar (about 12 inches).
Mineral veins such as these form where fluids move through fractured rocks, depositing minerals in the fractures and affecting chemistry of the surrounding rock. In this case, the veins have been more resistant to erosion than the surrounding host rock.