Spectral analyses of sabkha sediments with implications for remote sensing on Mars

Spectroscopic investigations of surface mineral components, expected to exist on the surface of Mars, using multiple spectral ranges and techniques, are vital to obtain the ground truth information or reference data for Mars exploration missions. This paper presents visible, near-infrared, thermal infrared reflectance and thermal infrared transmission spectra, as well as X-ray diffraction and scanning electron microscope/energy dispersive X-ray analyses of salt crusts and sediments interleaved with cyanobacterial materials from a coastal zone of the United Arab Emirates, where sabkhas exist. The samples obtained from sabkhas were characterized because they contain minerals requiring the water for formation and they provide a possible environment for some of the earliest organisms on Earth. The surface minerals identified include gypsum, calcite, halite, aragonite and dolomite. These sediments were found to be mixed with each other and intermingled with an algal mat, which consisted of cyanobacteria. If such materials formed in similar environments on Mars, their identification would be important for understanding the geobiological conditions of the planet and the potential habitability for life.