Digital water-level elevation contours for the Vamoosa-Ada aquifer in east-central 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 digitized water-level elevation contours for the
Vamoosa-Ada aquifer in east-central Oklahoma. The Vamoosa-Ada aquifer is an
important source of water that underlies about 2,320-square miles of parts of
Osage, Pawnee, Payne, Creek, Lincoln, Okfuskee, and Seminole Counties.
Approximately 75 percent of the water withdrawn from the Vamoosa-Ada aquifer is
for municipal use. Rural domestic use and water for stock animals account for
most of the remaining water withdrawn. The Vamoosa-Ada aquifer is defined in a
ground-water report as consisting principally of the rocks of the Late
Pennsylvanian-age Vamoosa Formation and overlying Ada Group. The Vamoosa-Ada
aquifer consists of a complex sequence of fine- to very fine-grained sandstone,
siltstone, shale, and conglomerate interbedded with very thin limestones. The
water-yielding capabilities of the aquifer are generally controlled by lateral
and vertical distribution of the sandstone beds and their physical
characteristics. The Vamoosa-Ada aquifer is unconfined where it outcrops in
about an 1,700-square-mile area.

The water-level elevation contours were digitized from a mylar map, at a scale
of 1:250,000, used to publish a plate in a ground-water report about the
Vamoosa-Ada aquifer. The water-level elevation contours in this data set extend
west of the aquifer outcrop to areas where Vanoss Group rocks overlie the Ada
Group. The data set also includes a water-level elevation contour for a terrace
deposit east of the aquifer outcrop near the North Canadian River. Water-level
elevations range from 800 to 1,000 feet above sea level for the Vamoosa-Ada
aquifer.