Digital boundaries of the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma

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.

This data set consists of digital aquifer boundaries for the alluvial and
terrace deposits along the Beaver-North Canadian River from the panhandle to
Canton Lake in northwestern Oklahoma. Ground water in 830 square miles of the
Quaternary-age alluvial and terrace aquifer is an important source of water for
irrigation, industrial, municipal, stock, and domestic supplies. The aquifer
consists of poorly sorted, fine to coarse, unconsolidated quartz sand with
minor amounts of clay, silt, and basal gravel. The hydraulically connected
alluvial and terrace deposits unconformably overlie the Tertiary-age Ogallala
Formation and Permian-age formations.

The aquifer boundaries established in a ground-water flow model for the aquifer
include areas: 1) where the terrace deposits pinch out against relatively
impermeable Permian-age formations; 2) where the alluvium has been deposited
against relatively impermeable Permian-age formations; 3) where the alluvial
and terrace deposits have been eroded and underlying Permian-age formations are
exposed at the surface; 4) where the aquifer extends beyond the geographic
limit of the study area; and 5) where the aquifer has little or no saturated
thickness.

The lines in the data set representing aquifer boundaries along geological
contacts were extracted from a published digital surficial geology data set
based on a scale of 1:250,000. The geographic limits of the aquifer and areas
of little or no saturated thickness were digitized from a folded paper map, at
a scale of 1:250,000 from a ground-water modeling report.