Rick Clawges, U.S. Geological Survey 2000 (Version 1.0, January 3, 2001) digital map NA NA Rapid City, South Dakota U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?sd_mnlsst_thk This data set is a polygon coverage created in ARC/INFO that represents the saturated thickness of the Minnelusa aquifer, Black Hills area, South Dakota. The unconfined zone of the Minnelusa aquifer is the area where the potentiometric surface of the aquifer is below the top of the formation. The elevation of the top of the potentiometric surface of the Minnelusa aquifer was subtracted from the top of the Minnelusa Formation, and the boundary of the unconfined zone was created where the calculation results equalled zero. The saturated thickness of the aquifer in the zone was determined by subtracting the elevation of the top of the Madison Limestone from the potentiometric surface elevation of the Minnelusa aquifer. The potentiometric surface and the tops of the formation were determined from water levels and geologic logs from selected wells drilled as of 1998. The thickness coverage contains polygons that have single integer values representing a range of thickness. This data set was created as part of the Black Hills Hydrology Study (BHHS). The BHHS is a long-term investigation that was initiated in 1990 as a cooperative effort between the U.S. Geological Survey (USGS), the South Dakota Department of Environment and Natural Resources (DENR), and the West Dakota Water Development District. West Dakota represents various local and county cooperators. The purpose of the study is to assess the quantity, quality, and distribution of surface and ground water in the Black Hills area of western South Dakota (Driscoll, 1992). The study area includes parts of Butte, Custer, Fall River, Lawrence, Meade, and Pennington counties in South Dakota. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ARC/INFO format, this metadata file may include some ARC/INFO-specific terminology. Reviews_Applied_to_Data: This electronic report was subjected to the same review standard that applies to all U.S. Geological Survey reports. Reviewers were asked to check the topological consistency, tolerances, attribute frequencies and statistics, projection, and geographic extent. The reviewers checked the metadata for completeness and accuracy. Related_Spatial_and Tabular_Data_Sets: Generalized thickness of the Minnelusa Formation (sd_mnls_thk), and the generalized thickness of the Madison Limestone and Englewood Formation(sd_mdsn_thk). Saturated thickness of the Madison aquifer (sd_mdsnst_thk). Other_References_Cited: Driscoll, D.G., 1992, Plan of study for the Black Hills Hydrology Study, South Dakota: U.S. Geological Survey Open-File Report 92-84, 10 p. 20000103 The thicknesses were based on water levels and geologic logs for selected wells drilled as of 1998. Complete None Planned -104.07994226 -102.95291642 44.78631611 43.11713452 none geology thickness Minnelusa aquifer ground water inlandWaters none Black Hills South Dakota USA none These data should not be used at scales larger than 1:250,000. Janet Carter U.S. Geological Survey Hydrologist mailing and physical address

1608 Mt. View Rd.

Rapid City South Dakota 57702 USA 1-888-275-8747 (605) 355-4523 (jmcarter@usgs.gov) Compilation of this data set and the associated metadata was funded by the U.S. Bureau of Reclamation. SunOS, 5.6, sun4u UNIX ARC/INFO version 8.0.1 Joel Galloway, U.S. Geological Survey 2000 paper map USGS Hydrologic Investigations Atlas HA-745-C Rapid City, South Dakota U.S. Geological Survey Janet Carter, U.S. Geological Survey 1999 paper map USGS Hydrologic Investigations Atlas HA-744-C Rapid City, South Dakota U.S. Geological Survey Janet Carter, U.S. Geological Survey 1999 paper map USGS Hydrologic Investigations Atlas HA-744-D Rapid City, South Dakota U.S. Geological Survey Multiple visual checks were done to verify that the attribute data was coincident with the original source map. Polygon and chain-node topology present. This data set consists of polygons with codes indicating ranges of saturated thickness of the Minnelusa aquifer in the vicinity of the Black Hills, South Dakota. none Joyce Williamson, U.S. Geological Survey 2000 digital maps Open-File Report OFR 00-471 Rapid City, South Dakota U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?ofr00471_mnlsscon http://water.usgs.gov/lookup/getspatial?ofr00471_mdsnscon http://water.usgs.gov/lookup/getspatial?ofr00471_mnlspcon http://water.usgs.gov/lookup/getspatial?ofr00471_mnlssurf 100000 digital maps 2000 Ground condition based on published data as of 1999 none Coverages of the geologic structure contours for the top of the Minnelusa Formation (mnlsscon), the geologic structure contours for the top of the Madison Limestone (mdsnscon), the potentiometric surface contours for the Minnelusa aquifer (mnlspcon), and a coverage of the overlying surficial deposits and absent areas for the Minnelusa Formation (mnlssurf), Black Hills area, South Dakota The following terminology used to describe the creation of the data set is from ARC/INFO. First, a polygon coverage of the study area boundary was converted to a grid coverage using the POLYGRID command. Line coverages containing elevation contours in the north half and south half of the study area of the structural surface of the Minnelusa Formation (mnls_topn and mnls_tops), the structural surface of the Madison Limestone (mdsn_topn and mdsn_tops), and the potentiometric surface of the Minnelusa aquifer (mnls_pot) were converted to grids using command TOPOGRID with a cellsize of 100 meters. Example: Arc: TOPOGRID mnlstop_ng 100 TOPOGRID: datatype contour TOPOGRID: contour mnls_topn altitude TOPOGRID: end Next, the grids of the top of the Minnelusa Formation in the north and south halves of the study area were merged using the GRID command MERGE. The grids of the top of the Madison Limestone in the north and south halves of the study area were merged and the grids of the potentiometric surface of the Minnelusa aquifer in the north and south halves were merged. To find where the Minnelusa aquifer is fully saturated (confined) and unconfined, the grid of the top of the formation (mnls_topg) was subtracted from the the grid of the potentiometric surface (mnlspotg). A boundary was created where the results of the calculation equal zero. The boundary was converted from a grid to a polygon using the ARC command GRIDPOLY. Using GRID, a grid of the top of the Madison Limestone was subtracted from the potentiometric surface grid of the Minnelusa aquifer (mnlspotg) to create a grid of the saturated thickness of the Minnelusa aquifer (mnlssatg) within the boundary defining the unconfined zone. The output grid was then reclassed into 6 general categories of thickness using a REMAP file to assign a range of values to a single integer value for an item named GRID-CODE. Using GRID, a grid was created where the Minnelusa Formation is absent or where there is not data (mnlsabsg). These areas where the Minnelusa Formation is absent or where the Minnelusa aquifer is fully saturated then were masked out. The grid was next converted to a polygon coverage using the GRIDPOLY command in GRID and the CLEAN command in ARC. The masking step eliminated nested polygons including some small areas of Minnelusa Formation outcrop. Since these areas can be partially saturated at depths of less than 100 ft, these selected polygons were added back to the final polygon coverage. A GRID-CODE of -9999 was assigned to areas where the Minnelusa Formation is absent and a GRID-CODE of 7 was assigned to areas where the Minnelusa aquifer is fully saturated. Finally, very small polygons in the coverages that had areas less than 10000 square meters were eliminated using the ARC command ELIMINATE. 20001229 First draft of metadata created by jgallowa using FGDCMETA.AML ver. 1.33 07/15/99 on ARC/INFO data set /home/bhhs/gis/jmg/aquiprop/metathick/mnlssat_thk 20010103 To ensure that coverage boundaries match those of other data layers created as part of this body of work, the study area boundary was added using APPEND. The coverage was then checked for excessive nodes in ARCEDIT using UNSPLIT NONE. The coverage was cleaned and all node and label errors checked. Polygon labels were editted for unique poly IDS using TABLES and IDEDIT. Note: Polygons were left with stair-stepped edges as a reminder that edges were generated using grids. In addition, the gap between the study area boundary and the saturated thickenss polygons is also an artificat of the grid coverage used in generating these polygons. 20010413 Vector Point 202 String 395 GT-polygon composed of chains 203 Point 8 Transverse Mercator 0.999600 -105.000000 500000.000000 0.000000 coordinate pair 1.0 1.0 Meters North American Datum of 1927 Clarke 1866 6378206.4 294.98 sd_mnlsst_thk.pat FID SHAPE AREA PERIMETER SD_MNLSST_THK# SD_MNLSST_THK-ID GRID-CODE > >SD_MNLSST_THK.PAT: > >COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME > 1 AREA 4 12 F 3 > 5 PERIMETER 4 12 F 3 > 9 SD_MNLSST_THK# 4 5 B - > 13 SD_MNLSST_THK-ID 4 5 B - > 17 GRID-CODE 4 8 B - > > AREA - Internal number for the area of the polygon in square meters PERIMETER - Internal number for the perimeter of the polygon in meters SD_MNLSST_THK# - Internal sequence number (i.e. the record number) of the polygon in the ARC file SD_MNLSST_THK-ID - User assigned feature ID GRID-CODE - An integer number indicating a range of saturated thickness according to the following table: GRID-CODE Range in saturated thickness (ft) 1 less than 200 2 200-400 3 400-600 4 600-800 5 800-1000 6 greater than 1000 7 fully saturated -9999 no data and areas where the formation is absent none U.S. Geological Survey Ask USGS - Water Webserver Team mailing

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Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+sd_mnlsst_thk Although this data set has been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data and related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Export Full coverage zipped 1 http://water.usgs.gov/GIS/dsdl/sd_mnlsst_thk.e00.gz SDTS Full coverage zipped 1 http://water.usgs.gov/GIS/dsdl/sd_mnlsst_thksdts.tgz Other Full coverage zipped 1 http://water.usgs.gov/GIS/dsdl/sd_mnlsst_thkshp.tgz None. This dataset is provided by USGS as a public service. 20041108 U.S. Geological Survey Ask USGS -- Water Webserver Team mailing

507 National Center

Reston VA 20192 1-888-275-8747 (1-888-ASK-USGS) http://answers.usgs.gov/cgi-bin/gsanswers?pemail=h2oteam&subject=GIS+Dataset+sd_mnlsst_thk FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998