There are three major layers of the Earths surface: Soil typically is at the surface (soil horizons are in BLUE in photo above). The USDA-NRCS is responsible for inventorying and mapping the soil resources of the U.S. Surficial geologic deposits, commonly called soft rock, is the un-weathered material below the soil layer and above hard bedrock. Most surficial deposits are of glacial origin in New England. Bedrock geology is the hard rock or ledge, it ranges anywhere from at the surface to more than 300 feet below the surface. Both surficial geology and bedrock geology are mapped by the USDI-USGS.