Mapping of Mars’ surface has revealed associations between phyllosilicate minerals and older terrains, and between sulfate minerals and younger terrains. This arrangement is hypothesized to be evidence for planetary-scale climate change, from conditions that favored the formation of phyllosilicates (e.g., higher water/rock ratio, moderate pH) to those that favored sulfates (e.g., lower water/rock ratio, lower pH). In early 2021, Curiosity began traversing through a region that orbital data suggest records such a mineralogical transition in a single stratigraphic sequence. Curiosity has investigated over 400 vertical meters of strata dominated by phyllosilicate-bearing, lacustrine mudstone. However, spectra from the CRISM and OMEGA instruments imply that the rover will soon reach strata with variable abundances of mono- and polyhydrated sulfates. We invite presentations on Curiosity results and those that provide context, such as what has been learned from orbit, in situ exploration of phyllosilicate- and sulfate-bearing strata, and laboratory or field analog studies.

• GSA: Geological Society of America -
• MSA: Mineralogical Society of America -