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Electromagnetic Induction, Gamma and Fluid Logs from Shallow Boreholes at the Callahan Mine Site: May 2017

Metadata Updated: October 29, 2025

From October 2016 to July 2018, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers and Maine Department of Transportation, collected surface, marine and borehole geophysical surveys to characterize the subsurface materials on land and under the water at a former mine facility in Brooksville, Maine. Borehole geophysical logs were collected in five boreholes from May 2-3, 2017 to identify geophysical properties, including the electrical properties and natural gamma emissions, which can be related to geologic materials behind casing. In addition, fluid electrical conductivity and temperature were collected through the water column in the well. Results can be used to identify the water level and the lithologic contacts in the subsurface. Natural gamma, fluid electrical conductivity, temperature and electromagnetic induction logs are provided in a series of files within a compressed (zip) file. Equipment used, measurement units and calibration information are described in the log files.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Created Date September 12, 2025
Metadata Updated Date October 29, 2025

Metadata Source

Harvested from DOI USGS DCAT-US

Additional Metadata

Resource Type Dataset
Metadata Created Date September 12, 2025
Metadata Updated Date October 29, 2025
Publisher U.S. Geological Survey
Maintainer
Identifier http://datainventory.doi.gov/id/dataset/usgs-5cc3d7dde4b09b8c0b7609bd
Data Last Modified 2020-08-25T00:00:00Z
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://ddi.doi.gov/usgs-data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 96aaea3a-3aed-4b4b-918c-7d32e7c86b0d
Harvest Source Id 2b80d118-ab3a-48ba-bd93-996bbacefac2
Harvest Source Title DOI USGS DCAT-US
Metadata Type geospatial
Old Spatial -68.82514, 44.32901, -68.79519, 44.35651
Source Datajson Identifier True
Source Hash 54882ab64a81163915a70368d93d06f36ad51b27a573d67b8e0adce3d2af214f
Source Schema Version 1.1
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