Freeze-thaw cycles drove chemical weathering and enriched sulfates in the Burns formation at Meridiani, Mars.

ABSTRACT: Sulfate-rich sedimentary rocks explored by the Opportunity rover during its 14-year surface mission at Meridiani Planum provide an invaluable window into the thousands of sulfate deposits detected on Mars via remote sensing. Existing models explaining the formation of martian sulfates can be generally described as either bottom-up, groundwater-driven playa settings or top-down icy chemical weathering environments. Here, we propose a hybrid model involving both bottom-up and top-down processes driven by freeze-thaw cycles. Freezing leads to cryo-concentration of acidic fluids from precipitations at the surface, facilitating rapid chemical weathering despite low temperatures. Cryosuction causes the upward migration of vadose water and even groundwater with dissolved ions, resulting in the ac

SUBMITTER: Liu J 

PROVIDER: S-EPMC10793949 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature