{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "Amy M. Hourigan", "hasEmail": "mailto:ahourigan@usgs.gov"}, "description": "Data about the top and bottom altitude, depth from land surface and/or the thickness of three geologic units in Tennessee were converted into geospatial format for this USGS data release from previously published paper maps and converted into digital formats for use by the public. The three geologic units were the Chattanooga Shale of Mississippian-Devonian age (Moore and Horton, 1999), the Wells Creek Dolomite of middle Ordovician age (Smith, 1959), and the Knox Group of lower Ordovician age (Newcome, 1954). These geologic units represent important geologic horizons across Tennessee. Geologic structure maps provide important information and, in digital format, support investigative and modeling efforts pertaining to water and mineral resources. Prior to this work, the paper source maps used for this data release existed in limited quantities, mainly restricted to the Nashville, TN offices of the Tennessee Department of Environment and Conservation (TDEC) and United States Geological Survey (USGS).\nThe work for this project included (1) scanning and georeferencing original paper maps to create georeferenced images (GRI), (2) digitizing well location points and contour lines, (3) populating well and contour attribute tables with data from maps and associated reports, and (4) when possible, interpolating raster surfaces for the three geologic units of top and bottom altitude, depth from land surface to the top and bottom surface, and thickness. All raster surfaces were aligned to a modified version of the National Hydrogeologic Grid (Clark and others, 2018) to support USGS Lower Mississippi Gulf Water Science Center efforts to create a statewide hydrogeologic framework. All horizontal coordinated data are projected to NAD 1983 USGS Contiguous USA Albers. The raster vertical coordinate information was referenced to the North American Vertical Datum of 1988 (NAVD 88). \nThis data release includes GRIs, vector data of the wells and mapped contours of top, bottom, or thickness, raster data, and related metadata files for each three geologic units under the associated child item tab.\nDataset types can be identified by the following naming convention:\ni_ = georeferenced map images (GRI)\npo_ = points\nc_ = contours and closed depressions\nf_= faults and other structural features\np_ = extent polygon\nra_ = altitude raster\nrd_ = depth from land surface raster\nrt_ = thickness raster\nThe datasets included on this main landing page are as follows:\nproject_metadata.xml \u2013 metadata file for general project information\nstudyarea_ext.zip:\np_chttshl_ext.shp - mapped extent of the Chattanooga Shale in Tennessee\np_wllscr_ext.shp - mapped extent of the Wells Creek Dolomite in Tennessee\np_knx_ext.shp - mapped extent of the Knox Group in Tennessee\nThe datasets included on the child item pages are as follows:\nChattanooga Shale: geospatial geologic structural datasets in Tennessee:\nchttshl_metadata.xml - metadata file     \nchttshl_alldata.zip:\nGRI/\ni_chttshl_btm.tif - structure contour map of the bottom of the Chattanooga Shale (Moore and Horton, 1999)\ni_chttshl_data.tif - map of data used to create structure and isopach maps (Moore and Horton, 1999)\ni_chttshl_thk.tif - thickness contour map for the Chattanooga Shale (Moore and Horton, 1999)\npolygons/\np_knx_ext.shp - study area extent for the Chattanooga Shale\np_hohenwald.shp - polygon for extend of the Hohenwald Platform (Moore and Horton, 1999) - supplemental data\nrasters/\nra_chttshl_btm.tif - altitude raster for the bottom of the Chattanooga Shale\nra_chttshl_tp.tif - altitude raster for the top of the Chattanooga Shale\nrd_chttshl_btm.tif - depth from land surface raster of the bottom of the Chattanooga Shale\nrd_chttshl_tp.tif - depth from land surface raster of the top of the Chattanooga Shale\nrt_chttshl.tif - thickness raster for the Chattanooga Shale\nvectors/\nc_chttshl_btm.shp - structure contours for the bottom of the Chattanooga Shale\nc_chttshl_btm_modified.shp - modified structure contours for the bottom of the Chattanooga Shale (hachures removed from closed basins). This vector used to interpolated raster for the bottom of the Chattanooga Shale\nc_chttshl_thk.shp - thickness contours for the Chattanooga Shale\nc_chttshl_thk_modified.shp - modified thickness contours for the Chattanooga Shale (hachures removed from closed basins). This vector used to interpolated raster for the thickness of the Chattanooga Shale\npo_chttshl.shp - point data of altitude and thickness for the Chattanooga Shale\nKnox Group: geospatial geologic structural datasets in Middle Tennessee:\nknx_metadata.xml - metadata file\nknx_alldata.zip:\nGRI/\ni_knx_tp.tif - structure contour map on the top of the Knox Group (Newcome, 1954)\ni_knx_outcrop.tif - map of the Wells Creek Disturbance (Wilson and Stearns, 1968)\npolygons/\np_chttshl_ext.shp - study area extent for the Knox Group\np_hohenwald.shp - extent of the Hohenwald Platform - supplemental data\nrasters/\nra_knx_tp.tif - altitude raster for the top of the Knox Group\nrd_knx_tp.tif - depth from land surface raster of the top of Knox Group\nvectors/\nc_knx_tp.shp - structure contours for the top of the Knox Group\nc_knx_tp_modified.shp - modified structure contours for the top of the Knox Group (hachures removed from closed basins). This vector used to interpolated raster for the top of the Knox Group\npo_knx_tp.shp - point data for the altitude of top of the Knox Group\nWells Creek Dolomite: geospatial geologic structural datasets in Tennessee:\nwllscr_metadata.xml - metadata file\nwllscr_alldata.zip:\nGRI/\ni_wllscr.tif - thickness contour map for the Wells Creek Dolomite (Smith, 1959)\npolygons/\np_wllscr_ext.shp - study area extent for the Wells Creek Dolomite\nrasters/\nra_wllscr_btm.tif - altitude raster for the bottom of the Wells Creek Dolomite (same dataset as ra_knx_tp.tif [Newcome, 1954; Smith, 1959])\nra_wllscr_tp.tif - altitude raster for the top of the Wells Creek Dolomite\nrd_wllscr_btm.tif - depth from land surface raster of the bottom of the Wells Creek Dolomite (same dataset as ra_knx_tp.tif [Newcome, 1954; Smith, 1959])\nrd_wllscr_tp.tif - depth from land surface raster of the top of the Wells Creek Dolomite\nrt_wllscr.tif - thickness raster for the Wells Creek Dolomite\nvectors/\nc_wllscr.shp - thickness contours for the Wells Creek Dolomite\npo_wllscr.shp - point data for the thickness of Wells Creek Dolomite\nReferences:\nMoore, J.L., and Horton, A.B., 1999, Structure and Isopach Maps of the Chattanooga Shale in Tennessee, Tennessee Dept. of Conservation, Division of Geology, Report of Investigations 48, 3 plates.\nNewcome, R. Jr., 1954, Structure contour map on top of the Knox Dolomite in Middle Tennessee, Tennessee Division of Geology, Ground-Water Investigations Preliminary Chart 5, 1 sheet.\nSmith, O. Jr., 1959, Isopach map of the Wells Creek Dolomite in Middle Tennessee: Tennessee Division of Water Resources, one sheet.\nWilson, C.W. and Stearns, R.G., 1968 Geology of the Wells Creek Structure, Tennessee: Tennessee Division of Geology, Bulletin 68, 248 p.", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/P135CN95", "description": "Landing page for access to the data", "format": "XML", "mediaType": "application/http", "title": "Digital Data"}, {"@type": "dcat:Distribution", "description": "The metadata original format", "downloadURL": "https://data.usgs.gov/datacatalog/metadata/USGS.66fae9a9d34e6d68f514c5a4.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_66fae9a9d34e6d68f514c5a4", "keyword": ["Central Basin", "Cumberland Plateau", "Highland Rim", "Tennessee", "USGS:66fae9a9d34e6d68f514c5a4", "contouring", "earth structure", "elevation", "geographic information systems", "geology", "geoscientificInformation", "geospatial datasets", "inlandWaters", "maps and atlases", "natural resource exploration", "stratigraphic thickness", "structure contours", "water resources"], "modified": "2025-02-11T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-89.1431, 34.7416, -83.6279, 36.6684", "theme": ["geospatial"], "title": "Geospatial geologic structural datasets, Chattanooga Shale, Wells Creek Dolomite, and Knox Group, Tennessee, USA"}