Audiomagnetotelluric sounding data collected in 2018 in this area to understand subsurface geologic structure.

Gravity data collected 2016 through 2018 at 1080 locations to assist in mapping subsurface geology in northeastern Iowa. Data are provided in CSV format.

Audiomagnetotelluric (AMT) sounding data collected in 2008 in this area in support of assessments of concealed mineral resources.

Gravity data collected from 2016 through 2019 to assist in mapping surface and subsurface geology in this area. Data are provided in CSV and shapefile formats.

Audiomagnetotelluric station locations and data to characterize subsurface rock properties important for understanding surface water and groundwater quality issues, and also to improve knowledge of deep geologic structures that may have been conduits for hydrothermal fluids that formed mineral deposits.

Magnetotelluric station locations and data intended to help to characterize subsurface rock properties important for understanding surface water and groundwater quality issues, and also to improve knowledge of deep geologic structures that may have been conduits for hydrothermal fluids that formed mineral deposits.

Audio-magnetotelluric sounding data collected in 2017 in this area to understand geologic structure and lithologic variations.

Shallow soil characteristics were mapped using an electromagnetic sensor in October 2018. Data were acquired by towing the sensor on a wheeled cart behind an all-terrain vehicle (ATV), with the sensor at a height of 0.432 meters (m) above the ground surface. Data are provided in CSV format.

Geochemical data from selected USGS projects from the 1960s-1980s that were previously not published as digital data. Includes geochemical analyses from 36,498 samples of various types using analytical methods and instruments that were current when those studies were carried out. Data are provided in Microsoft Access, shapefile, and CSV formats.