The combination of morphological and topographic information from stereo images, as well as compositional data from near-infrared spectroscopy has been proven to be a powerful tool for understanding the geology of Mars.
Beginning with the OMEGA instrument on the European Space Agency’s Mars Express orbiter in 2003, the surface of Mars has been examined at near-infrared wavelengths by imaging spectrometers that are capable of detecting specific minerals and mapping their spatial extent. The CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) instrument on our orbiter is a visible/near-infrared imaging spectrometer, and the HiRISE camera works together with it to document the appearance of mineral deposits detected by this orbital prospecting… [More at link]