Revised source area groups for Fe grain fingerprint matching

The source areas characterized for Fe grain geochemistry are listed by number and name for the circum-Arctic Ocean coastal and shelf areas, as well as east and south Greenland, and west and northwest Iceland. One file lists all samples used in the source data set for the Arctic Ocean, Greenland, and Iceland along with the latitude and longitude as well as other information. The Fe grain geochemistry data file contains more than 39,000 Fe grain analyses used to match similar Fe grains (anhydrous Fe oxide minerals such as ilmenite, hematite, titanomahgnetite, magnetite, chromite, and varieties of these) that form in igneous and metamorphic terrains and are eroded and deposited in coastal environments. The process of matching similar Fe grains from marine ice-rafted deposits to individual Fe grains in the source data set is described in Darby et al., 2015, Journal of Sedimentary Research.