Quantification and geological implications of manganese, barium, and copper observed by MarSCoDe LIBS at Zhurong landing site on Mars

Abstract

<p>The Mars Surface Composition Detector (MarSCoDe) onboard the Zhurong rover, China's first Mars rover, includes a laser-induced breakdown spectroscopy (LIBS) instrument that enables quantitative analysis of Martian surface elemental composition. We developed quantitative models for manganese (Mn), barium (Ba), and copper (Cu) using respective lab datasets. The optimal model for each element is selected from combinations of various multivariate regression algorithms and feature extractions. Additionally, the model's accuracy and behaviors on the onboard MarSCoDe Calibration Targets (MCCTs) were evaluated. We obtained Mn, Ba, and Cu concentrations for 36 Martian targets detected by MarSCoDe LIBS during the first 300 sols (Martian days). For MarSCoDe rock targets, Mn is primarily associated with Fe, with olivines and pyroxenes being the main source of Mn; however, the overall contents of Ba and Cu are low in MarSCoDe rock targets, and their host minerals remain unclear. Based on the current results, MarSCoDe rocks should be primarily composed of igneous minerals, with minimal alteration preserving their original composition. Additionally, an Fe-Al-Mn-bearing phase was observed in a dune target, potentially clay minerals, suggesting that external inputs may have influenced the dune's composition. This work provides new evidence for the elemental and mineral composition as well as the potential geological processes of the Zhurong landing site. <br></p>