Digital data sets that describe aquifer characteristics of the Antlers aquifer in southeastern Oklahoma

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.

本数据集包含俄克拉荷马州东南部安特勒斯含水层（Antlers aquifer）的数字化含水层边界。早白垩世时期的安特勒斯砂岩（Antlers Sandstone）是一片区域的重要供水来源，该区域覆盖约4400平方英里的阿特卡县、布莱恩县、卡特县、乔克托县、约翰斯顿县、洛夫县、马歇尔县、麦柯蒂恩县以及普什马塔哈县的全部或部分辖区。露矿区的安特勒斯含水层由砂岩、黏土、砾岩与石灰岩构成；其上部则由砂岩床、胶结程度较差的砂岩、砂质页岩、粉砂及黏土组成。在约1800平方英里的露矿范围内，安特勒斯含水层为无压含水层。

本数据集涵盖俄克拉荷马州境内安特勒斯砂岩的露矿区，以及安特勒斯砂岩被冲积沉积、阶地沉积覆盖的区域，还包含少量薄而零散的古德兰石灰岩（Goodland Limestone）露头区。绝大多数含水层边界线均从已公开的数字化地质数据集中提取得到；部分边界线则通过插值法生成，这类区域多位于溪流、河流附近且安特勒斯含水层被冲积沉积与阶地沉积覆盖的地带。经插值生成的边界线与安特勒斯含水层地下水模拟报告中公布的含水层边界高度吻合。本数据集所依托的底图，均源自比例尺为1:250000的公开印刷地图，经扫描或数字化处理后得到。