MID-CONTINENT MARINE ECOSYSTEMS? - HYPERSALINE SPRINGS AS A POTENTIAL ANALOGUE FOR MARS

Hypersaline springs host unique mid-continent marine ecosystems in central Manitoba, Canada. Springs originate from a reflux of glacial meltwater which intruded into underlying bedrock and dissolved buried salt beds. Two spring types were distinguished based both on flow rate and geochemistry. High flow springs (greater than 10 l/s) hosted extensive marine microbial mats. Microbial mats were dominated by algae but included diverse microbes that varied somewhat between springs. In contrast, low flow springs were affected by solar evaporation, increasing salinity, and temperature, relative to high flow sites. These springs may form a potential analogue for a Martian groundwater system driven by basal melt of polar icecaps, leading to proglacial spring discharge. If these groundwater systems intersected evaporate deposits along the flow path, then hypersaline springs very similar to those found in Manitoba could develop. Just as the Manitoba springs provide a terrestrial habitat for marine organisms, proglacial hypersaline springs may have formed a last-refuge for life during a period of cold-trapping of Martian waters on the poles