A Brine‐Driven Formation Model for Brain Terrain in Qaidam Basin: Implications for Martian Habitability

Abstract The search for water and signs of life is a primary goal of Mars exploration. Various landforms on Mars indicate past surface liquid water activity, but the distribution of liquid water in the shallow subsurface remains poorly constrained. Notably, brain terrains, widespread on Mars, may record subsurface brine activity. We conducted radar detection, stratigraphic trenching, remote sensing, and mineralogical analysis in a Mars‐like area in the Qaidam Basin. The study revealed a sandwich structure (salt crust–sand–salt crust) in brain terrains and verified that subsurface brine is more active beneath brain terrain ridges than beneath troughs. This evidence suggests that brain terrains evolve from salt polygons. The brine channel beneath the brain terrain ridge marks the pathway where brine once upwelled during polygon ridge formation. This offers new insights into subsurface brine and potential habitability on Mars. Furthermore, we updated the global distribution of potential brain terrains for future Mars exploration.