SAND_GRAVEL_RESOURCES_IN is a polygon shapefile that identifies sand and gravel permissive tracts in the surficial unconsolidated deposits of Indiana. Permissive tracts have been defined by the U.S. Geological Survey (Open File Report 95-681, Singer, D.A., 1993, Basic concepts in three-part quantitative assessments of undiscovered mineral resources: Nonrenewable Resources, v. 2, no. 2, p. 69-81) as "areas where the geology permits the existence of mineral deposits (mineral resource potential) of a specific type... Noting that the possibility of the occurrence of the specified deposit type (mineral resource) outside the permissive tract should be negligible." This shapefile provides an approximate economic ranking of the sand and gravel resource potential of each mapped surficial unconsolidated deposit. The resource potential of each map unit within the mapped surficial unconsolidated deposits is ranked as a "potential," "low potential," or "not a potential" resource. The definitions of these rankings are derived from Gray, H. H., 1973, Properties and uses of geologic materials in Indiana: Indiana Geological Survey Regional Geologic Map Supplementary Chart 1 and Carr, D. D., and Webb, W. M., 1970, Sand and gravel resources of Indiana: Indiana Geological Survey Bulletin 42-D, 31 p. "Potential resource" indicates that the surficial unconsolidated deposits are likely to contain economic concentrations of sand and gravel, "low potential" indicates that the surficial unconsolidated deposits may contain economic concentrations of sand and gravel, and "not a potential resource" indicates that the surficial unconsolidated deposits do not contain economic concentrations of sand and gravel.