The U.S. Geological Survey, in cooperation with the U.S. Air Force Civil Engineer Center, collected borehole geophysical data and completed simple aquifer tests to estimate the thickness and hydraulic properties of surficial deposits. The purpose of data collection was to create generalized contour maps of Pierre Shale elevation and surficial deposit thickness within and near Ellsworth Air Force Base (study area). Natural gamma and electromagnetic induction data were collected to refine or determine surficial deposit thickness at selected wells. Additionally, data from previous geophysical studies and driller logs were compiled and combined with results from natural gamma and electromagnetic induction data to provide a more spatially complete image of the subsurface. Borehole nuclear magnetic resonance (bNMR) data were collected to estimate hydraulic conductivity and water content of surficial deposits overlying Pierre Shale. Simple aquifer tests using water slugs (slug tests) were completed to estimate hydraulic conductivity of surficial deposits, and results were compared to hydraulic conductivity estimates from bNMR data. All data used to construct maps and estimate hydraulic properties are provided in an accompanying U.S. Geological Survey data release (available at https://doi.org/10.5066/P9FLR79F).
Generalized contour maps were constructed using results from 26 borehole geophysical logs, 35 geophysical transects from previous studies, and 304 wells with driller logs. Pierre Shale elevation generally followed land-surface topography, sloping from high elevations in the north to lower elevations in the south. Topographic highs of Pierre Shale, where present, could act as groundwater divides that potentially affect groundwater flow direction. Surficial deposit thickness varied spatially and ranged from 0 to 86 feet. Surficial deposits generally were thickest in higher elevation areas near ephemeral streams in the northern part of the study area. Hydraulic conductivity estimated from bNMR results using two analytical methods ranged from 0.1 to 2,314 feet per day, whereas hydraulic conductivity estimated from slug tests ranged from 0.001 to 193 feet per day. Hydraulic conductivity estimates from slug tests were plotted with surficial deposit thickness contours instead of bNMR estimates because bNMR estimates were determined to overestimate hydraulic conductivity. Hydraulic conductivity values generally were greater in the southwestern part of study area than the northeastern part.
Citation Information
Publication Year | 2023 |
---|---|
Title | Maps of elevation of top of Pierre Shale and surficial deposit thickness with hydraulic properties from borehole geophysics and aquifers tests within and near Ellsworth Air Force Base, South Dakota, 2020–21 |
DOI | 10.3133/sim3502 |
Authors | Colton J. Medler, William G. Eldridge, Todd M. Anderson, Stephanie N. Phillips |
Publication Type | Report |
Publication Subtype | USGS Numbered Series |
Series Title | Scientific Investigations Map |
Series Number | 3502 |
Index ID | sim3502 |
Record Source | USGS Publications Warehouse |
USGS Organization | Dakota Water Science Center |
Related Content
Datasets Used to Create Maps of Pierre Shale Elevation and Surficial Deposit Thickness within and near Ellsworth Air Force Base, South Dakota, 2021
Electrical Resistivity Tomography (ERT) and Horizontal-to-Vertical Spectral Ratio (HVSR) Data Collected Within and Near Ellsworth Air Force Base, South Dakota, from 2014 to 2019
Related Content
- Data
Datasets Used to Create Maps of Pierre Shale Elevation and Surficial Deposit Thickness within and near Ellsworth Air Force Base, South Dakota, 2021
This data release contains borehole geophysical data collected within and near Ellsworth Air Force Base, South Dakota, from September 2020 to August 2021. The data accompanies a USGS scientific investigations map from Medler and others (2022). The U.S. Geological Survey, in cooperation with the U.S. Air Force Civil Engineer Center, collected borehole geophysical data and performed simple aquiferElectrical Resistivity Tomography (ERT) and Horizontal-to-Vertical Spectral Ratio (HVSR) Data Collected Within and Near Ellsworth Air Force Base, South Dakota, from 2014 to 2019
This data release contains geophysical data from electrical resistivity tomography (ERT) and passive seismic surveys within and near Ellsworth Air Force Base, South Dakota, collected June 2014?September 2019. The data accompanies a USGS scientific invesgations map from Medler and Anderson (2021; LINK HERE) and a USGS scientific investigations report by Bender and others (2021; LINK HERE). The U.S - Connect