New Mexico Geological Society Annual Spring Meeting — Abstracts

The Quebradas area near Socorro, New Mexico, contains Paleozoic evaporite deposits including massive gypsum in the Yeso and Atrasado Formations. Due to the accessibility of this location as a field site and the presence of sulfate-rich deposits, the Quebradas provide a potential location to study Martian analog evaporites. In September of 2023, teams from NASA’s Goddard Space Flight Center and Johnson Space Center sampled gypsum from the Yeso Formation to test its viability as a depositional analog for sulfates found in Gale Crater, Mars. We characterized carbon preserved in the evaporites as proof of concept for future sampling efforts to find organic carbon compounds using the Sample Analysis at Mars instrument suite aboard Curiosity Rover.

During an internship at Goddard Space Flight Center in the summer of 2024, we measured total carbon using infrared spectrophotometry with an ELTRA CW800M Multiphase Elemental Analyzer to provide insight into the error and precision of the instrument and to constrain which samples should be given priority in future measurements. We also evaluated organic carbon preservation using the much more precise, but more time-consuming, process of evolved gas analysis mass spectrometry. Before spectrophotometric analysis, the mineralogy of each sample was determined using powdered X-ray diffraction (pXRD). Overall, total carbon content was consistent with the mineralogy determined by pXRD. Samples containing little to no carbonate minerals contained little to no total carbon, whereas samples containing even minor amounts of carbonate had total carbon proportional to their carbonate content. Most sulfate-dominated samples had minimal carbon, with some exceptions. Although trends of measurements are consistent with the expected results, exceptions are important as they highlight specific sampling sites or mineralogies that may be best suited as Martian analogs. These exceptions should be analyzed further using organic carbon and evolved gas analyses to help inform future analog sampling efforts.