HiRISE high-resolution images are used to analyze the geomorphologies in Mclaughlin crater at Mawrth Vallis on Mars.
Spectral features of hyper-spectral CRISM data are enhanced through band ratio to reduce the residuals of the
instrumental calibration and atmospheric correction. Spectral analysis shows that this crater not only bears spectral
features of phyllosilicates such as montmorillonite, nontronite and serpentine, but also exhibits spectral features of
carbonate minerals. The co-existence of these diverse alteration minerals produced in different conditions indicates that
the geochemical environment in this crater had been altered many times. Two hypotheses are proposed to explain the
causes of this mineral diversity: 1) carbonate and other minerals were formed firstly by infiltration metasomatism
underground, and then excavated and exposed by later impact; 2) the impact excavated the basalt/olivine-dominant
Martian crust, and the long cooling and crystallization differentiation process of the impact-generated hydrothermal
system formed these diverse minerals.