Research into the deep biosphere requires an understanding of both the microbial community at a given site and the geochemical and hydrological factors that support that microbial community. To highlight the interplay between geochemistry and microbiology in these deep environments, we characterized the hydrogeologic and geochemical systems of a 2.7 Ga banded iron formation within the Canadian Shield in the Soudan Underground Mine State Park in Minnesota, USA, a site known to host a lithotrophic microbial community. Calcium-sodium-chloride brines, characteristic of deep groundwaters throughout the Canadian Shield, were found in the site with total dissolved solids as high as 116,000 ppm in one borehole. Comparison of the Soudan waters to those found at other sites in the Canadian Shield or other sites of deep biosphere research indicate that they are notable for their high magnesium concentrations relative to total salinity. Additionally, the most saline Soudan waters have distinct 2H
how important is that, that those have ended up and how important is that for the epa? methane reduction is important in helping the environment. you will see coming soon a very aggressive regulation looking at both new and existing methane sources from oil and gas, the oil and gas sector so we are really excited about the conversation happening in congress, but we re not totally reliant on what s happening in congress. you talk about what we re going to see coming. there was some talk that the epa was going to release some new rules for methane this week. is that what you re referring to, and when could we expect those? you know, we are looking at in the coming days, if not weeks, proposing a very aggressive rule on methane emissions for both new and existing sources, and in there you will see the most aggressive approach for reducing methane