Chemical and isotopic fingerprints of MDRS carbonates
The potential of extraterrestrial life on Mars is well connected to the history, and distribution of water and carbon on the planet. Carbonate minerals are seen as powerful tools with which to explore these fundamental relationships, as they are intimately tied to both the water and the inorganic carbon cycle. Some local deposits of carbonates have been discovered on the surface of Mars and in meteorites. The wide ranging set of observations of carbonate minerals, provided by an unprecedented series of robotic missions to Mars, not only defined new constraints on the history of Martian climate, but also opened unique windows into primordial Martian aqueous environments. While questions about habitability remain unanswered at this time, we are obtaining more and more information about the environments in which water has existed on the Martian surface. The research frontier is to focus the resolution on the variability of the different mineral forming environments, rather than try to see Mars as a one uniform environment.
An ongoing study is being conducted in the Weizmann Institute of Science, Israel, aimed at understanding the chemical and isotopic fingerprint of carbonate forming environments on Mars. The research is active in three different areas: in situ observations, lab simulations and comparisons to analogue environments. The MDRS environment is analogous to, for example, a specific type of arid environment that we hypothesise about in our isotopic fractionation models. Therefore, it is important to compare the chemical and isotopic fingerprints of carbonates at MDRS with those anticipated in such an arid environment. This way future studies of Martian geology, for instance by the Mars 2020 rover, will be able to better determine the environment in which the samples were originally formed. In addition, the previous studies on the MDRS environment have laid a number of constraints, which thus make MDRS a very good candidate analogue environment to study.
The planned carbonate analysis field work will concentrate on locating and sampling carbonate minerals in the topsoil and exhumed formation in the vicinity of the MDRS. The procedure of locating the carbonates will be conducted in several ways. First of all, the potential site selection will be based on previous studies and the geological mapping of the area. Field analysis, with hand-handled remote sensing spectroscopy instruments, will be used to locate and verify carbonates/carbonate bearing assemblages. The samples will be sent for analysis of the carbonates’ chemical and isotopic fingerprint at the Weizmann Institute of Science. The results will be added to our datasets with the intention of publishing them in academic journals.