Groundwater-Driven Evolution of Prebiotic Alkaline Lake Environments

Area of Science:

• Astrobiology and Geochemistry
• Origin of Life Studies

Background:

• Alkaline lakes are proposed environments for prebiotic synthesis due to phosphate accumulation via evaporation.
• Conflicting chemical and physical conditions in current models limit understanding of life's origins in these settings.

Purpose of the Study:

• To investigate the physical and chemical dynamics of active alkaline lakes relevant to prebiotic chemistry.
• To reconcile the distinct environmental requirements for prebiotic synthesis and early cellular function.

Main Methods:

• Near-surface geophysics
• Aqueous geochemistry
• Hydrogeologic modeling
• Study of Last Chance and Goodenough Lakes, Canada

Main Results:

• Extreme phosphate enrichment requires geomorphologically-driven evaporation.
• Evaporation contrasts drive Rayleigh-Taylor instabilities and vigorous water cycling.
• Reconciles conflicting requirements for UV light, salinity, metal concentration, and pH.

Conclusions:

• Alkaline lake dynamics facilitate both prebiotic reaction networks and habitable conditions for early life.
• Complex physical and chemical processing in these lakes supports the co-occurrence of synthesis and early evolution.