Here in Nili Fossae,we see the light toned sediments in the floor of a the crater. The ancient layered rocks surrounding the sediments in pale whitish and bluish tones. They are partially covered by ripples made up of dust and other wind blown sediments. This crater floor is part of a system that formed when water probably flowed through Nili Fossae in the distant past.
Orbital spectral measurements by the OMEGA instrument on Mars Express and CRISM on MRO detected an abundance of clay minerals of different types in the layered sediments inside Nili Fossae, along with other minerals that are typical of sediments that were deposited by water. The various colors and tones of the layered rocks record changes in the composition of the sediments, details that can tell us about changes in the Martian environment eons ago. Nili Fossae is a candidate site for a future landed robotic mission that could traverse across these layers and make measurements that could be used to unravel a part of the early history of Mars. Nili Fossae is a history book that is waiting to be read.