This geospatial data set consists of the bedrock formations of the High Plains aquifer, which underlies parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming.
This data set was created to assist in the regional analysis of water quality in the High Plains aquifer as part of the National Water- Quality Assessment (NAWQA) program - High Plains Region study unit.
Introduction
This data set consists of polygons representing the underlying bedrock formations of the High Plains aquifer. The data set was composed through the integration of two map sources that were digitally captured. The first source was used to define the exterior boundaries of the High Plains aquifer. The second source defines interior boundaries of the underlying bedrock formations. These formations underlie parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This data set is intended for regional analysis only, as the precise boundaries of these formations are not well defined and, therefore, are somewhat subjective in nature.
The exterior boundary, defining the extent of the aquifer, was acquired through a previously digitized 1:1,000,000-scale map of the High Plains aquifer that was originally created by Donald Schild and Debra Spahr as part of the Regional Aquifer Systems Analysis (RASA) program. The original source map for the High Plains aquifer boundary was drawn on mylar by Weeks and Gutentag in 1979 (OFR 80-50). This was in turn simplified by McGrath and Dugan in 1993 (WRI 93-4008). This version by McGrath and Dugan is used as the aquifer boundary in this coverage.
Boundaries for the bedrock formations were acquired from a documented graphical representation of the bedrock formations of the High Plains aquifer originally created by Gutentag and others (1984) at a 1:6,336,000 scale.
Reviews Applied to Data --
Other References Cited -- Gutentag, E.D., Heimes, F.J., Krothe, N.C., Luckey, R.R., and Weeks, J.B., 1984, Geohydrology of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Professional Paper 1400-B, 63 p.
McGrath, T., and Dugan, J.T., 1993, Water-level changes in the High Plains Aquifer--Predevelopment to 1991: U.S. Geological Survey Water-Resource Investigations Report 93-4088, 53 p.
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 (USGS), U.S. Department of the Interior, no warranty expressed or implied is made by the USGS 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 USGS in the use of this data set, software, or related materials.
HPBEDROCK.PAT:
COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME
1 AREA 4 12 F 3
5 PERIMETER 4 12 F 3
9 HPBEDROCK# 4 5 B -
13 HPBEDROCK-ID 4 5 B -
17 GEO_UNIT 25 25 C -
HPBEDROCK.AAT:
COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME
1 FNODE# 4 5 B -
5 TNODE# 4 5 B -
9 LPOLY# 4 5 B -
13 RPOLY# 4 5 B -
17 LENGTH 4 12 F 3
21 HPBEDROCK# 4 5 B -
25 HPBEDROCK-ID 4 5 B -
GEO_UNIT- Describes the bedrock formation underlying the High Plains
aquifer. This attribute consists of five categories:
OLIGOCENE- Refers to bedrock formations that originated during the
geologic time period of the Oligocene and now underlie the
High Plains aquifer.
UPPER CRETACEOUS- This attribute refers to the bedrock formation
of the Upper Cretaceous age that currently underlies the High Plains
aquifer.
LOWER CRETACEOUS- This attribute refers to the bedrock formations
associated with the Lower Cretaceous that currently underlies
the High Plains aquifer.
JURASSIC AND TRIASSIC- This attribute refers to bedrock formations
of the Jurassic and Triassic age that now underlay the High Plains
aquifer.
PERMIAN- This attribute refers to bedrock formations of
Permian age that currently underlie the High Plains aquifer.
ISLAND- This attribute refers to areas where there is no geologic
formation associated with the aquifer.
TERTIARY- This attribute refers to bedrock formations of
Tertiary age that currently underlie the High Plains aquifer.
Although these data have 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.
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 set, software, or related materials.