Becker, Carol J. Runkle, Donna Rea, Alan 1997 1.0 map Open-File Report 96-452 Reston, VA U.S. Geological Survey http://water.usgs.gov/lookup/getspatial?ofr96-452_aqbound This data set consists of digital aquifer boundaries for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The Tillman terrace aquifer encompasses the unconsolidated terrace deposits and alluvium associated with the North Fork of the Red River and the Red River in the western half of Tillman County. These sediments consist of discontinuous layers of clay, sandy clay, sand, and gravel. The aquifer extends over an area of 285 square miles and is used for irrigation and domestic purposes. Granite and the Hennessey Formation outcrop in northern parts of the aquifer where alluvial deposits are absent. These outcrops were included as part of the aquifer in a thesis that modeled the ground-water flow in the aquifer. Most of the aquifer boundary polygons were extracted from a published digital surficial geology data set based on a scale of 1:250,000. One of the lines in the aquifer boundary data set was digitized from a figure in a thesis in which ground-water flow was modeled for the Tillman terrace and alluvial aquifer. This data set was created for a project to develop data sets to support ground-water vulnerability analysis. The objective was to create and document a digital geospatial data set from a published report or map, or existing digital geospatial data sets that could be used in ground-water vulnerability analysis. Introduction -- This data set consists of digital aquifer boundaries for the Tillman terrace and alluvial aquifer in southwestern Oklahoma. The ground-water flow model of the Tillman terrace and alluvial aquifer in a thesis by Al-Sumait (1978) encompasses the unconsolidated terrace deposits and alluvium associated with the North Fork of the Red River and the Red River in the western half of Tillman County. These sediments consist of discontinuous layers of clay, sandy clay, sand, and gravel (Al-Sumait, 1978). The aquifer extends over an area of 285 square miles and is used for irrigation and domestic purposes. Granite and the Hennessey Formation outcrop in northern parts of the aquifer where alluvial deposits are absent. These outcrops were modeled by Al-Sumait (1978) as part of the aquifer. Most of the aquifer boundary polygons were extracted from a published digital surficial geology data set titled, "Digital geologic map of Lawton quadrangle, southwestern Oklahoma," by Cederstrand (1996) based on a scale of 1:250,000. The geologic contacts from the digital data set (Cederstrand, 1996) match the geologic contacts shown in figure 2 of Al-Sumait (1978). One of the lines in the aquifer boundary data set was digitized from figure 4 in the thesis, "A computer ground-water model for the Tillman alluvium in Tillman County, Oklahoma," by Al-Sumait (1978, p. 17). 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. Reviewers were given digital data sets and paper plots for checking against the source maps to verify the linework and attributes. The reviewers checked the metadata and a_readme.1st files for completeness and accuracy. Related Spatial and Tabular Data Sets -- This data set is one of four digital map data sets being published together for this aquifer. The four data sets are: > aqbound - aquifer boundaries > cond - hydraulic conductivity > recharg - aquifer recharge > wlelev - water-level elevation contours Digital map data sets of the Oklahoma surficial geology digitized from 1:250,000-scale maps (or 1:125,000-scale maps for the three Oklahoma panhandle counties) are published separately. Other References Cited -- Al-Sumait, A.J., 1978, A computer ground-water model for the Tillman alluvium in Tillman County, Oklahoma: Stillwater, OK, Oklahoma State University, master's thesis, 152 p., 48 figs. Cederstrand, J.R., 1996, Digital geologic map of Lawton quadrangle, southwestern Oklahoma: U.S. Geological Survey Open-File Report 96-376, scale 1:250,000, 3 diskettes. (Available in nonproprietary and ARC/INFO formats.) URL:http://wwwok.cr.usgs.gov/gis/geology/index.html Environmental Systems Research Institute, Inc. (ESRI), 1995, ARC/INFO Command Reference, ARC/INFO On-line manuals: Redlands, CA. Notes -- 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 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. 1978 publication date Complete None planned -99.2274 -98.9262 34.6426 34.1691 none ground-water vulnerability groundwater vulnerability aquifers ground water groundwater Tillman terrace and alluvial aquifer Tillman terrace aquifer Tillman aquifer Tillman alluvial aquifer Tillman alluvial and terrace aquifer terrace aquifer alluvial aquifer terrace deposit alluvial deposit terrace and alluvial aquifer alluvial and terrace aquifer aquifer boundary inlandWaters none southwestern Oklahoma None. This data set was constructed from digital data sets by Cederstrand (1996) that were scan digitized from mylar maps at a scale of 1:250,000 and represent the boundaries as reported by Al-Sumait (1978). Boundaries represented at this scale are indicative of broad, regional trends and should not be interpreted as site specific. Carol J. Becker U.S. Geological Survey Hydrologist mailing address

202 NW 66th St., Bldg. 7

Oklahoma City Oklahoma 73116 United States of America 1-888-275-8747 (405) 843-7712 cjbecker@usgs.gov none http://water.usgs.gov/lookup/get?OFR96-452/browse.gif A browse image of the four aquifer data sets. GIF Compilation of this data set and the associated metadata was funded under a cooperative Joint Funding Agreement between the U.S. Geological Survey and the State of Oklahoma, Office of the Secretary of Environment. Public UNCLASSIFIED None Operating System-- UNIX, ARC/INFO Version 7.0.3,(Mon Mar 13 22:21:55 PST 1995) Cederstrand, Joel R. 1996 1.0 map Open-File Report 96-376 Oklahoma City, OK U.S. Geological Survey http://wwwok.cr.usgs.gov/gis/geology/index.html Polygon and chain-node topology present. This data set includes all the aquifer boundaries shown on figure 2, page 11 by Al-Sumait (1978). Aquifer boundaries with a value of 2 for the LSOURCE line attribute were taken from Cederstrand (1996). The northern aquifer boundaries have a value of 1 for the LSOURCE line attribute and were taken from Al-Sumait (1978). None 25 meters Resolution as reported None. A tic data set was created using 1:250,000-scale U.S. Geological Survey quadrangle maps. 19960319 Lines were selected from the digital geologic data set (Cederstrand, 1996) that represented the aquifer boundaries. 19960613 The data set was edited and dangling nodes were deleted. The ARC/INFO command CLEAN (ESRI, 1995) was used with a fuzzy tolerance of 82 feet (25 meters) ground distance and a node snap of 82 feet (25 meters) ground distance. Polygons were attributed for AQTYPE and lines were attributed for LSOURCE. 19960614 Vector Point 4 String 9 GT-polygon composed of chains 5 Albers Conical Equal Area 29.5 45.5 -96 23 0.0 0.0 coordinate pair 25 meters 25 meters METERS North American Datum of 1983 Geodetic Reference System 80 6378137 298.257 AQBOUND.PAT Polygon attribute table of AQBOUND ARC/INFO - Polygon attribute table of AQBOUND ARC/INFO - n/a n/a AREA Area of polygon in square coverage units Computed Positive real numbers n/a n/a PERIMETER Perimeter of polygon in coverage units Computed Positive real numbers n/a n/a AQBOUND# Internal feature number Computed Sequential unique positive integer n/a n/a AQBOUND-ID User-assigned feature number User-defined Integer n/a n/a AQTYPE Aquifer type Al-Sumait (1978) 1,4 n/a n/a MINOR1 Blank item for DLG Calculated 0 n/a n/a MAJOR1 Aquifer type Al-Sumait (1978) 1,4 n/a n/a AQBOUND.AAT Arc attribute table ARC/INFO - Arc attribute table ARC/INFO - n/a n/a FNODE# Internal number of from-node Computed Sequential unique positive integer n/a n/a TNODE# Internal number of to-node Computed Sequential unique positive integer n/a n/a LPOLY# Internal number of poly to left of arc Computed Sequential unique positive integer n/a n/a RPOLY# Internal number of poly to right of arc Computed Sequential unique positive integer n/a n/a LENGTH Length of arc in coverage units Computed Positive real numbers n/a n/a AQBOUND# Internal feature number Computed Sequential unique positive integer n/a n/a AQBOUND-ID User-assigned feature number User-defined Integer n/a n/a LSOURCE Source of line Al-Sumait (1978), Cederstrand (1996) 1,2 n/a n/a MINOR1 Blank item for DLG Calculated 0 n/a n/a MAJOR1 Source of line Al-Sumait (1978), Cederstrand (1996) 1,2 n/a n/a Each polygon in this data set has an associated attribute, AQTYPE, with values of 1 representing areas where the aquifer is present and 4 representing areas where the aquifer is absent and geologic units other than the aquifer outcropped but were modeled as part of the aquifer in the ground-water flow model by Al-Sumait (1978). AQTYPE is stored in the first major code (MAJOR1) for polygons, and 0 is stored in the first minor code (MINOR1) in the Digital Line Graph (DLG) version of this data set. Each line in this digital data set has an associated attribute, LSOURCE, that contains a code to indicate the source of the line. An LSOURCE code of 1 indicates the line was taken from Al-Sumait (1978), and an LSOURCE of 2 indicates the line was taken from Cederstrand (1996). LSOURCE is stored in the first major code (MAJOR1) for lines, and 0 is stored in the first minor code (MINOR1) in the Digital Line Graph (DLG) version of this data set. See overview. 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+ofr96-452_aqbound 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/ofr96-452_aqbound.e00.gz Other DLG file format zipped 1 http://water.usgs.gov/GIS/dsdl/ofr96-452_aqbound.dlg.gz None. This dataset is provided by USGS as a public service. 20041108 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+ofr96-452_aqbound FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998