Box modelling the transfer of sulfur on Mars using Earth as a geochemical analogue

Volcanism was once the primary source of sulfur transport on Mars, and its present-day surface preserves a geological record of these mineralogical processes. Sulfur plays a key part in the eruption process, forming sulfides, and less commonly sulfates in the magma chamber, and being expelled as sulfur dioxide-rich gas. However, there is a mismatch between the location of existing volcanic provinces and detections of high sulfur abundances measured through satellite instruments such as the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) and the Gamma Ray Spectrometer (GRS). Despite similarly hosting a basaltic surface, the sulfur content in Martian meteorites (408–2700 ppm) and by Martian dust measured by rovers (2 wt% S) exceeds Earth’s basalts by almost an order of magnitude. This study attempts to account for the observed abundance of sulfur through applying comparative planetology using Earth’s volcanoes, including both eruptive and quiescent degassing rates and solid leachate particles. The study successfully provided order-of-magnitude estimates of the mass of sulfur produced in volcanism over the Noachian-Hesperian periods of >3.7 to 3.1 Ga and it provided values similar to previous studies. However, it was not possible to confirm mass balance due to large uncertainties in the mass of sulfur in the sedimentary reservoir.