There are three major layers of the Earth’s surface: Soil typically is at the surface (soil horizons are in BLUE). The USDA-NRCS is responsible for inventorying and mapping the soil resources of the U.S. Surficial geologic deposits, commonly called soft rocks, is the un-weathered material below the soil layer and above bedrock. Most surficial deposits are glacial deposits 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 UDI-USGS.
