Supplemental Material: Major ion pore-water chemistry evolution in Lake Michigan benthic sediments: Evidence for direct input from Michigan Basin saline groundwater

Detailed information on locations (Table S1) and sediment descriptions (Table S2) of the 1999 sediment gravity cores, overviews of major cation pore-water chemistry analysis procedures and quality assurance/quality control protocols (Tables S3 and S4), and additional information on sources and modifications to the generalized regional bedrock geology compilation (Table S5); figures depicting calcium versus sodium variations in pore-water samples (Fig. S1) and depicting sediment descriptions and corresponding changes in pore-water sodium concentrations (Fig. S2); and data tables of pore-water composition analyses (chloride, bromide, and major cations) for the Lake Michigan (Data S1 and S2) and Saginaw Bay (Lake Huron) (Data S3) samples presented in the paper.