Digital boundaries of the Antlers aquifer in southeastern 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 aquifer boundaries of the Antlers aquifer
in southeastern Oklahoma. The Early Cretaceous-age Antlers Sandstone is an
important source of water in an area that underlies about 4,400-square miles of
all or part of Atoka, Bryan, Carter, Choctaw, Johnston, Love, Marshall,
McCurtain, and Pushmataha Counties. The Antlers aquifer consists of sand, clay,
conglomerate, and limestone in the outcrop area. The upper part of the Antlers
aquifer consists of beds of sand, poorly cemented sandstone, sandy shale, silt,
and clay. The Antlers aquifer is unconfined where it outcrops in about an
1,800-square-mile area.

The data set includes the outcrop area of the Antlers Sandstone in Oklahoma and
areas where the Antlers is overlain by alluvial and terrace deposits and a few
small thin outcrops of the Goodland Limestone. Most of the aquifer boundary
lines were extracted from published digital geology data sets. Some of the
lines were interpolated in areas where the Antlers aquifer is overlain by
alluvial and terrace deposits near streams and rivers. The interpolated lines
are very similar to the aquifer boundaries published in a ground-water modeling
report for the Antlers aquifer. The maps from which this data set was derived
were scanned or digitized from maps published at a scale of 1:250,000.

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