The Knox Dolomite is currently recognized as the Knox Group. The Mascot Dolomite, the upper unit of the Knox Group, is dolomite and dolomitic limestone of Lower-Ordovician-age that occurs in the subsurface of most of Tennessee. This data release will focus on Middle Tennessee, where the only outcrop of the Knox Group is in the Wells Creek basin in Stewart and Houston counties (Bradley, 1986; Wilson and Stearns, 1968). The top of the Knox Dolomite is an erosional surface that is useful as a structural datum because of the importance of the Knox Group for oil and gas resources, zinc mineralization, and domestic drinking water supplies. Since the upper approximately 30 meters of the Knox Group is paleokarst, groundwater is generally under confined conditions (Bradley, 1986; Wilson and Stearns, 1968). This upper portion of the Knox is often low-yielding and variable in water quality. However, it can be a reliable aquifer in specific areas - mostly in the Central Basin. A structure contour map on the Knox Group in Middle Tennessee was prepared by Newcome (1954) as a part of a cooperative program of groundwater investigations by the U.S. Geological Survey and the Tennessee Division of Geology at Nashville, Tennessee. Prior to this work, this paper map existed in limited quantities, mainly restricted to the Nashville offices of the Tennessee Department of Environment and Conservation (TDEC) and United States Geological Survey (USGS). The map measuring 46 x 64 cm, with an approximate scale of 1:500,000 was prepared with well elevation data, determined by aneroid barometer or from topographic quadrangle maps (Newcome, 1954). Structure contours were drawn on top of Knox Group at 100 feet intervals. The work for this project consisted of (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) interpolating raster surfaces for the top altitude of the Knox Group and depth from land surface to the top of the unit. 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. Vertical coordinate information was referenced to the North American Vertical Datum of 1988 (NAVD 88). Dataset types can be identified by the following naming convention: i_ = georeferenced map images (GRI) po_ = points c_ = contours and closed depressions f_= faults and other structural features p_ = extent polygon(s) ra_ = altitude raster rd_ = depth from land surface raster rt_ = thickness raster The datasets included on this child item page are as follows: knx_metadata.xml - metadata file knx_alldata.zip: GRI/ i_knx_tp.tif - structure contour map on the top of the Knox Group (Newcome, 1954) i_knx_outcrop.tif - map of the Wells Creek Disturbance (Wilson and Stearns, 1968) polygons/ "p_knx_ext" - extent polygon for the Knox Group "p_knx_outcrop" - extent polygon the Wells Creek Structure - Knox Group outcrop rasters/ ra_knx_tp.tif - altitude raster for the top of the Knox Group (NAVD 88) (meters) rd_knx_tp.tif - depth from land surface raster of the top of Knox Group (meters) vectors/ c_knx_tp.shp - structure contours for the top of the Knox Group (NGVD 29) (feet) c_knx_tp_modified.shp - modified structure contours for the top of the Knox Group (hachures removed from closed basins). This vector used to interpolate raster for the top of the Knox Group (NGVD 29) (feet) po_knx_tp.shp - point data for the altitude of top of the Knox Group (NGVD 29) (feet) References: Bradley, M. W., 1986, Preliminary Evaluation of the Knox Group in Tennessee for Receiving Injected Wastes, U.S. Geological Survey, Environmental Protection Agency,

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). The 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). This 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. Dataset types can be identified by the following naming convention: i_ = georeferenced map images (GRI) po_ = points c_ = contours and closed depressions f_= faults and other structural features p_ = extent polygon ra_ = altitude raster rd_ = depth from land surface raster rt_ = thickness raster The datasets included on this main landing page are as follows: project_metadata.xml – metadata file for general project information studyarea_ext.zip: p_chttshl_ext.shp - mapped extent of the Chattanooga Shale in Tennessee p_wllscr_ext.shp - mapped extent of the Wells Creek Dolomite in Tennessee p_knx_ext.shp - mapped extent of the Knox Group in Tennessee The datasets included on the child item pages are as follows: Chattanooga Shale: geospatial geologic structural datasets in Tennessee: chttshl_metadata.xml - metadata file chttshl_alldata.zip: GRI/ i_chttshl_btm.tif - structure contour map of the bottom of the Chattanooga Shale (Moore and Horton, 1999) i_chttshl_data.tif - map of data used to create structure and isopach maps (Moore and Horton, 1999) i_chttshl_thk.tif - thickness contour map for the Chattanooga Shale (Moore and Horton, 1999) polygons/ p_knx_ext.shp - study area extent for the Chattanooga Shale p_hohenwald.shp - polygon for extend of the Hohenwald Platform (Moore and Horton, 1999) - supplemental data rasters/ ra_chttshl_btm.tif - altitude raster for the bottom of the Chattanooga Shale ra_chttshl_tp.tif - altitude raster for the top of the Chattanooga Shale rd_chttshl_btm.tif - depth from land surface raster of the bottom of the Chattanooga Shale rd_chttshl_tp.tif - depth from land surface raster of the top of the Chattanooga Shale rt_chttshl.tif - thickness raster for the Chattanooga Shale vectors/ c_chttshl_btm.shp - structure contours for the bottom of the Chattanooga Shale c_chttshl_btm_modified.shp - modified structure contours for the bottom

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). The 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). This 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. Dataset types can be identified by the following naming convention: i_ = georeferenced map images (GRI) po_ = points c_ = contours and closed depressions f_= faults and other structural features p_ = extent polygon ra_ = altitude raster rd_ = depth from land surface raster rt_ = thickness raster The datasets included on this main landing page are as follows: project_metadata.xml – metadata file for general project information studyarea_ext.zip: p_chttshl_ext.shp - mapped extent of the Chattanooga Shale in Tennessee p_wllscr_ext.shp - mapped extent of the Wells Creek Dolomite in Tennessee p_knx_ext.shp - mapped extent of the Knox Group in Tennessee The datasets included on the child item pages are as follows: Chattanooga Shale: geospatial geologic structural datasets in Tennessee: chttshl_metadata.xml - metadata file chttshl_alldata.zip: GRI/ i_chttshl_btm.tif - structure contour map of the bottom of the Chattanooga Shale (Moore and Horton, 1999) i_chttshl_data.tif - map of data used to create structure and isopach maps (Moore and Horton, 1999) i_chttshl_thk.tif - thickness contour map for the Chattanooga Shale (Moore and Horton, 1999) polygons/ p_knx_ext.shp - study area extent for the Chattanooga Shale p_hohenwald.shp - polygon for extend of the Hohenwald Platform (Moore and Horton, 1999) - supplemental data rasters/ ra_chttshl_btm.tif - altitude raster for the bottom of the Chattanooga Shale ra_chttshl_tp.tif - altitude raster for the top of the Chattanooga Shale rd_chttshl_btm.tif - depth from land surface raster of the bottom of the Chattanooga Shale rd_chttshl_tp.tif - depth from land surface raster of the top of the Chattanooga Shale rt_chttshl.tif - thickness raster for the Chattanooga Shale vectors/ c_chttshl_btm.shp - structure contours for the bottom of the Chattanooga Shale c_chttshl_btm_modified.shp - modified structure contours for the bottom

The Wells Creek Dolomite is the lowest unit of the Stones River Group. The Wells Creek consists of cherty limestone that underlies the Murfreesboro Limestone of the Stones River Group of Middle Ordovician age, and directly overlies the Knox Group of early Ordovician and late Cambrian age. The unit ranges in thickness from less than 1.52 meters (5 feet) in the eastern part of the Central Basin to approximately 54.86 meters (180 feet) in Stewart County. The depth of the Wells Creek generally ranges from 121.92 meters to 457.2 meters (from 400 to 1500 feet) below land surface (Smith, 1959). The Wells Creek Dolomite does not yield water but it can be easily recognized when drilling wells and it overlies the Knox Group, a deep aquifer in middle Tennessee and a significant source of groundwater for some areas. For this data release, the raster interpolated for the top of the Knox Group in Middle Tennessee (ra_knx_tp.tif) was also used to represent the altitude of the bottom of the Wells Creek Dolomite (See process steps for more details). An isopach map of the thickness of the Wells Creek Dolomite in Middle Tennessee was prepared as a part of a cooperative groundwater study by the Tennessee Division of Geology and the U.S. Geological Survey (USGS) (Smith, 1959). The 43 x 71 cm map covers parts of Middle Tennessee, from Camden east to Crossville, and from the Kentucky border to the Alabama border. The map scale is approximately 1:600,000. Contour intervals are 5 feet (east of the 100-foot isopach) and 10 feet (west of the 100-foot isopach), which show the thickness of the Wells Creek Dolomite. The associated data are altitude values from a study of cuttings in 120 wells between the western boundary of the Cumberland Plateau and the Tennessee River (Smith, 1959). Prior to the current work, the Wells Creek Dolomite isopach map (Smith, 1959) 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). The work for this project consisted of (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) interpolating raster surfaces for the thickness of the Wells Creek Dolomite using the data from the isopach map (Smith, 1959), altitude of the bottom of the Wells Creek Dolomite by using the data for the top of the Knox Group (Newcome, 1954), altitude of the top of the Wells Creek Dolomite using the bottom of the Wells Creek Dolomite added to the thickness of the Wells Creek Dolomite (Smith, 1959), and depth from land surface to the top and bottom of the Wells Creek (USGS, 2012). 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. Raster vertical coordinate information was referenced to the North American Vertical Datum of 1988 (NAVD 88). Dataset types can be identified by the following naming convention: "i_" = georeferenced map images (GRI) "po_" = points "c_" = contours "p_" = extent polygons "ra_" = altitude raster "rd_" = depth from land surface raster "rt_" = thickness raster The datasets included on this child item page are as follows: wllscr_metadata.xml - metadata file wllscr_alldata.zip: GRI/ i_wllscr.tif - thickness contour map for the Wells Creek Dolomite (Smith, 1959) polygon/ p_wllscr_ext.shp - study area extent for the Wells Creek Dolomite rasters/ ra_wllscr_btm.tif - altitude raster for the bottom of the Wells Creek Dolomite (same dataset as ra_knx_tp.tif [Newcome, 1954; Smith, 1959]) (NAVD 88) (meters) ra_wllscr_tp.tif - altitude raster for the top of the

The Wells Creek Dolomite is the lowest unit of the Stones River Group. The Wells Creek consists of cherty limestone that underlies the Murfreesboro Limestone of the Stones River Group of Middle Ordovician age, and directly overlies the Knox Group of early Ordovician and late Cambrian age. The unit ranges in thickness from less than 1.52 meters (5 feet) in the eastern part of the Central Basin to approximately 54.86 meters (180 feet) in Stewart County. The depth of the Wells Creek generally ranges from 121.92 meters to 457.2 meters (from 400 to 1500 feet) below land surface (Smith, 1959). The Wells Creek Dolomite does not yield water but it can be easily recognized when drilling wells and it overlies the Knox Group, a deep aquifer in middle Tennessee and a significant source of groundwater for some areas. For this data release, the raster interpolated for the top of the Knox Group in Middle Tennessee (ra_knx_tp.tif) was also used to represent the altitude of the bottom of the Wells Creek Dolomite (See process steps for more details). An isopach map of the thickness of the Wells Creek Dolomite in Middle Tennessee was prepared as a part of a cooperative groundwater study by the Tennessee Division of Geology and the U.S. Geological Survey (USGS) (Smith, 1959). The 43 x 71 cm map covers parts of Middle Tennessee, from Camden east to Crossville, and from the Kentucky border to the Alabama border. The map scale is approximately 1:600,000. Contour intervals are 5 feet (east of the 100-foot isopach) and 10 feet (west of the 100-foot isopach), which show the thickness of the Wells Creek Dolomite. The associated data are altitude values from a study of cuttings in 120 wells between the western boundary of the Cumberland Plateau and the Tennessee River (Smith, 1959). Prior to the current work, the Wells Creek Dolomite isopach map (Smith, 1959) 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). The work for this project consisted of (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) interpolating raster surfaces for the thickness of the Wells Creek Dolomite using the data from the isopach map (Smith, 1959), altitude of the bottom of the Wells Creek Dolomite by using the data for the top of the Knox Group (Newcome, 1954), altitude of the top of the Wells Creek Dolomite using the bottom of the Wells Creek Dolomite added to the thickness of the Wells Creek Dolomite (Smith, 1959), and depth from land surface to the top and bottom of the Wells Creek (USGS, 2012). 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. Raster vertical coordinate information was referenced to the North American Vertical Datum of 1988 (NAVD 88). Dataset types can be identified by the following naming convention: "i_" = georeferenced map images (GRI) "po_" = points "c_" = contours "p_" = extent polygons "ra_" = altitude raster "rd_" = depth from land surface raster "rt_" = thickness raster The datasets included on this child item page are as follows: wllscr_metadata.xml - metadata file wllscr_alldata.zip: GRI/ i_wllscr.tif - thickness contour map for the Wells Creek Dolomite (Smith, 1959) polygon/ p_wllscr_ext.shp - study area extent for the Wells Creek Dolomite rasters/ ra_wllscr_btm.tif - altitude raster for the bottom of the Wells Creek Dolomite (same dataset as ra_knx_tp.tif [Newcome, 1954; Smith, 1959]) (NAVD 88) (meters) ra_wllscr_tp.tif - altitude raster for the top of the

The Chattanooga Shale is relatively thin and generally continuous across the state, making it an important geologic horizon. In Tennessee, the Chattanooga Shale crops out along the escarpment between the Central Basin and the surrounding Highland Rim, in several river valleys and in folded areas outside the basin, and crops out around the Wells Creek, Howell, and Flynn Creek impact structures (Conant and Swanson, 1961). The Devonian-Mississippian-aged Chattanooga Shale is often abbreviated as "MDc.” Data related to the thickness, depth from land surface, and elevation of the unit are useful for resource exploration. Information from 1,615 oil well and surface data points were used to produce the structure map on the Chattanooga Shale in Tennessee by the Tennessee Department of Environment and Conservation, Division of Geology (Moore and Horton, 1999). The data used in 1999 were acquired from previously drawn structure maps on the base of the Chattanooga Shale and compiled into computer-generated contour lines and maps. The original publication, Structure and isopach maps of the Chattanooga Shale in Tennessee, included three 84x57 cm maps, at an approximate scale of 1:500,000. The paper maps include a structure map on the base of the formation, an isopach map, and a location map of the data points representing wells used to prepare the original structure maps. The three maps associated with the original publication were digitized and rasterized for this project. The work for this project consisted of (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) interpolating raster surfaces for the top and bottom altitude, depth from land surface to the top and bottom surface, and thickness of the Chattanooga Shale in Tennessee. 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. Raster vertical coordinate information was referenced to the North American Vertical Datum of 1988 (NAVD 88). Dataset types can be identified by the following naming convention: i_ = georeferenced map images (GRI) po_ = points c_ = contours and closed depressions f_= faults and other structural features p_ = extent polygon ra_ = altitude raster rd_ = depth from land surface raster rt_ = thickness raster The datasets included on this child item page are as follows: chttshl_metadata.xml - metadata file chttshl_alldata.zip: GRI/ i_chttshl_btm.tif - structure contour map of the bottom of the Chattanooga Shale (Moore and Wilson, 1999) i_chttshl_data.tif - map of data used to create structure and isopach maps (Moore and Horton, 1999c) i_chttshl_thk.tif - thickness contour map for the Chattanooga Shale (Moore and Horton, 1999b) polygons/ p_chttshl_ext_ext.shp - study area extent for the Chattanooga Shale (Moore and Wilson, 1999) p_hohenwald.shp - polygon for extend of the Hohenwald Platform (Moore and Horton, 1999b) - supplemental data rasters/ ra_chttshl_btm.tif - altitude raster for the bottom of the Chattanooga Shale (NAVD 88) (meters) ra_chttshl_tp.tif - altitude raster for the top of the Chattanooga Shale (NAVD 88) (meters) rd_chttshl_btm.tif - depth from land surface raster of the bottom of the Chattanooga Shale (meters) rd_chttshl_tp.tif - depth from land surface raster of the top of the Chattanooga Shale (meters) rt_chttshl.tif - thickness raster for the Chattanooga Shale (meters) vectors/ c_chttshl_btm.shp - structure contours for the bottom of the Chattanooga Shale (NGVD 29) (feet) c_chttshl_btm_modified.shp - modified structure contours for the bottom of the Chattanooga Shale (hachures removed from closed

The Chattanooga Shale is relatively thin and generally continuous across the state, making it an important geologic horizon. In Tennessee, the Chattanooga Shale crops out along the escarpment between the Central Basin and the surrounding Highland Rim, in several river valleys and in folded areas outside the basin, and crops out around the Wells Creek, Howell, and Flynn Creek impact structures (Conant and Swanson, 1961). The Devonian-Mississippian-aged Chattanooga Shale is often abbreviated as "MDc.” Data related to the thickness, depth from land surface, and elevation of the unit are useful for resource exploration. Information from 1,615 oil well and surface data points were used to produce the structure map on the Chattanooga Shale in Tennessee by the Tennessee Department of Environment and Conservation, Division of Geology (Moore and Horton, 1999). The data used in 1999 were acquired from previously drawn structure maps on the base of the Chattanooga Shale and compiled into computer-generated contour lines and maps. The original publication, Structure and isopach maps of the Chattanooga Shale in Tennessee, included three 84x57 cm maps, at an approximate scale of 1:500,000. The paper maps include a structure map on the base of the formation, an isopach map, and a location map of the data points representing wells used to prepare the original structure maps. The three maps associated with the original publication were digitized and rasterized for this project. The work for this project consisted of (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) interpolating raster surfaces for the top and bottom altitude, depth from land surface to the top and bottom surface, and thickness of the Chattanooga Shale in Tennessee. 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. Raster vertical coordinate information was referenced to the North American Vertical Datum of 1988 (NAVD 88). Dataset types can be identified by the following naming convention: i_ = georeferenced map images (GRI) po_ = points c_ = contours and closed depressions f_= faults and other structural features p_ = extent polygon ra_ = altitude raster rd_ = depth from land surface raster rt_ = thickness raster The datasets included on this child item page are as follows: chttshl_metadata.xml - metadata file chttshl_alldata.zip: GRI/ i_chttshl_btm.tif - structure contour map of the bottom of the Chattanooga Shale (Moore and Wilson, 1999) i_chttshl_data.tif - map of data used to create structure and isopach maps (Moore and Horton, 1999c) i_chttshl_thk.tif - thickness contour map for the Chattanooga Shale (Moore and Horton, 1999b) polygons/ p_chttshl_ext_ext.shp - study area extent for the Chattanooga Shale (Moore and Wilson, 1999) p_hohenwald.shp - polygon for extend of the Hohenwald Platform (Moore and Horton, 1999b) - supplemental data rasters/ ra_chttshl_btm.tif - altitude raster for the bottom of the Chattanooga Shale (NAVD 88) (meters) ra_chttshl_tp.tif - altitude raster for the top of the Chattanooga Shale (NAVD 88) (meters) rd_chttshl_btm.tif - depth from land surface raster of the bottom of the Chattanooga Shale (meters) rd_chttshl_tp.tif - depth from land surface raster of the top of the Chattanooga Shale (meters) rt_chttshl.tif - thickness raster for the Chattanooga Shale (meters) vectors/ c_chttshl_btm.shp - structure contours for the bottom of the Chattanooga Shale (NGVD 29) (feet) c_chttshl_btm_modified.shp - modified structure contours for the bottom of the Chattanooga Shale (hachures removed from closed

The Digital Bedrock Geologic-GIS Map of the Lancing Quadrangle, Tennessee is composed of GIS data layers and GIS tables, and is available in the following GRI-supported GIS data formats: 1.) an ESRI file geodatabase (lanc_bedrock_geology.gdb), and a 2.) Open Geospatial Consortium (OGC) geopackage. The file geodatabase format is supported with a 1.) ArcGIS Pro 3.X map file (.mapx) file (lanc_bedrock_geology.mapx) and individual Pro 3.X layer (.lyrx) files (for each GIS data layer). Upon request, the GIS data is also available in ESRI shapefile format. Contact Stephanie O'Meara (see contact information below) to acquire the GIS data in these GIS data formats. In addition to the GIS data and supporting GIS files, three additional files comprise a GRI digital geologic-GIS dataset or map: 1.) a readme file (obed_geology_gis_readme.pdf), 2.) the GRI ancillary map information document (.pdf) file (obed_geology.pdf) which contains geologic unit descriptions, as well as other ancillary map information and graphics from the source map(s) used by the GRI in the production of the GRI digital geologic-GIS data for the park, and 3.) a user-friendly FAQ PDF version of the metadata (lanc_bedrock_geology_metadata_faq.pdf). Please read the obed_geology_gis_readme.pdf for information pertaining to the proper extraction of the GIS data and other map files. QGIS software is available for free at: https://www.qgis.org/en/site/. The data were completed as a component of the Geologic Resources Inventory (GRI) program, a National Park Service (NPS) Inventory and Monitoring (I&M) Division funded program that is administered by the NPS Geologic Resources Division (GRD). For a complete listing of GRI products visit the GRI publications webpage: https://www.nps.gov/subjects/geology/geologic-resources-inventory-products.htm. For more information about the Geologic Resources Inventory Program visit the GRI webpage: https://www.nps.gov/subjects/geology/gri.htm. At the bottom of that webpage is a "Contact Us" link if you need additional information. You may also directly contact the program coordinator, Jason Kenworthy (jason_kenworthy@nps.gov). Source geologic maps and data used to complete this GRI digital dataset were provided by the following: University of Tennessee, Tectonics and Structural Geology Research Group. Detailed information concerning the sources used and their contribution the GRI product are listed in the Source Citation section(s) of this metadata record (lanc_bedrock_geology_metadata.txt or lanc_bedrock_geology_metadata_faq.pdf). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale of 1:24,000 and United States National Map Accuracy Standards features are within (horizontally) 12.2 meters or 40 feet of their actual location as presented by this dataset. Users of this data should thus not assume the location of features is exactly where they are portrayed in ArcGIS Pro, QGIS or other software used to display this dataset. All GIS and ancillary tables were produced as per the NPS GRI Geology-GIS Geodatabase Data Model v. 2.3. (available at: https://www.nps.gov/articles/gri-geodatabase-model.htm).

The Digital Bedrock Geologic-GIS Map of the Lancing Quadrangle, Tennessee is composed of GIS data layers and GIS tables, and is available in the following GRI-supported GIS data formats: 1.) an ESRI file geodatabase (lanc_bedrock_geology.gdb), and a 2.) Open Geospatial Consortium (OGC) geopackage. The file geodatabase format is supported with a 1.) ArcGIS Pro 3.X map file (.mapx) file (lanc_bedrock_geology.mapx) and individual Pro 3.X layer (.lyrx) files (for each GIS data layer). Upon request, the GIS data is also available in ESRI shapefile format. Contact Stephanie O'Meara (see contact information below) to acquire the GIS data in these GIS data formats. In addition to the GIS data and supporting GIS files, three additional files comprise a GRI digital geologic-GIS dataset or map: 1.) a readme file (obed_geology_gis_readme.pdf), 2.) the GRI ancillary map information document (.pdf) file (obed_geology.pdf) which contains geologic unit descriptions, as well as other ancillary map information and graphics from the source map(s) used by the GRI in the production of the GRI digital geologic-GIS data for the park, and 3.) a user-friendly FAQ PDF version of the metadata (lanc_bedrock_geology_metadata_faq.pdf). Please read the obed_geology_gis_readme.pdf for information pertaining to the proper extraction of the GIS data and other map files. QGIS software is available for free at: https://www.qgis.org/en/site/. The data were completed as a component of the Geologic Resources Inventory (GRI) program, a National Park Service (NPS) Inventory and Monitoring (I&M) Division funded program that is administered by the NPS Geologic Resources Division (GRD). For a complete listing of GRI products visit the GRI publications webpage: https://www.nps.gov/subjects/geology/geologic-resources-inventory-products.htm. For more information about the Geologic Resources Inventory Program visit the GRI webpage: https://www.nps.gov/subjects/geology/gri.htm. At the bottom of that webpage is a "Contact Us" link if you need additional information. You may also directly contact the program coordinator, Jason Kenworthy (jason_kenworthy@nps.gov). Source geologic maps and data used to complete this GRI digital dataset were provided by the following: University of Tennessee, Tectonics and Structural Geology Research Group. Detailed information concerning the sources used and their contribution the GRI product are listed in the Source Citation section(s) of this metadata record (lanc_bedrock_geology_metadata.txt or lanc_bedrock_geology_metadata_faq.pdf). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale of 1:24,000 and United States National Map Accuracy Standards features are within (horizontally) 12.2 meters or 40 feet of their actual location as presented by this dataset. Users of this data should thus not assume the location of features is exactly where they are portrayed in ArcGIS Pro, QGIS or other software used to display this dataset. All GIS and ancillary tables were produced as per the NPS GRI Geology-GIS Geodatabase Data Model v. 2.3. (available at: https://www.nps.gov/articles/gri-geodatabase-model.htm).

This digital data release contains geospatial data for the 1:250,000 scale geologic map of the Grand Island 1 degree by 2 degree quadrangle, Nebraska, originally published by Dreeszen and others (1973). The database includes line and polygon features depicting the extent of the Miocene Ogallala Formation and underlying Cretaceous rocks. The original map also included shaded patches indicating outcrop areas, and contour lines depicting the thickness of Quaternary deposits; these are not included in this database. The spatial data are accompanied by non-spatial tables that describe the sources of geologic information, a description of geologic map units, a glossary of terms, and a Data Dictionary that duplicates the Entity and Attribute information contained in the metadata file.