Skip Links

USGS - science for a changing world

Open-File Report 2011-1035

Prepared in cooperation with the Bureau of Land Management

Geophysical Investigation of Red Devil Mine Using Direct-Current Resistivity and Electromagnetic Induction, Red Devil, Alaska, August 2010

By Bethany L. Burton and Lyndsay B. Ball

Thumbnail of cover and link to download report PDF (14.2 MB)

Red Devil Mine, located in southwestern Alaska near the Village of Red Devil, was the state's largest producer of mercury and operated from 1933 to 1971. Throughout the lifespan of the mine, various generations of mills and retort buildings existed on both sides of Red Devil Creek, and the tailings and waste rock were deposited across the site. The mine was located on public Bureau of Land Management property, and the Bureau has begun site remediation by addressing mercury, arsenic, and antimony contamination caused by the minerals associated with the ore deposit (cinnabar, stibnite, realgar, and orpiment).

In August 2010, the U.S. Geological Survey completed a geophysical survey at the site using direct-current resistivity and electromagnetic induction surface methods. Eight two-dimensional profiles and one three-dimensional grid of direct-current resistivity data as well as about 5.7 kilometers of electromagnetic induction profile data were acquired across the site. On the basis of the geophysical data and few available soil borings, there is not sufficient electrical or electromagnetic contrast to confidently distinguish between tailings, waste rock, and weathered bedrock. A water table is interpreted along the two-dimensional direct-current resistivity profiles based on correlation with monitoring well water levels and a relatively consistent decrease in resistivity typically at 2–6 meters depth.

Three settling ponds used in the last few years of mine operation to capture silt and sand from a flotation ore processing technique possessed conductive values above the interpreted water level but more resistive values below the water level. The cause of the increased resistivity below the water table is unknown, but the increased resistivity may indicate that a secondary mechanism is affecting the resistivity structure under these ponds if the depth of the ponds is expected to extend below the water level. The electromagnetic induction data clearly identified the three monofills and indicate, in conjunction with the three-dimensional resistivity data, additional possible landfill features on the north side of Red Devil Creek.

No obvious shallow feature was identified as a possible source for a spring that is feeding into Red Devil Creek from the north bank. However, a discrete, nearly vertical conductive feature observed on the direct-current resistivity line that passes within 5 meters of the spring may be worth investigating. Additional deep soil borings that better differentiate between tailings, waste rock, and weathered bedrock may be very useful in more confidently identifying these rock types in the direct-current resistivity data.

First posted March 17, 2011

For additional information contact:

USGS Crustal Geophysics and Geochemistry Science Center
Box 25046, Mail Stop 964
Denver, CO 80225

This report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge.

Suggested citation:

Burton, B.L., and Ball, L.B., 2011, Geophysical investigation of Red Devil mine using direct-current resistivity and electromagnetic induction, Red Devil, Alaska, August 2010: U.S. Geological Survey Open-File Report 2011–1035 , 53 p.




Site Background

Site History

Site Geology and Hydrogeology

Purpose and Scope

Methods of Investigation

Direct-Current Resistivity Method

Data Acquisition

Data Processing and Inversion

Electromagnetic Induction Method

Data Acquisition

Data Processing and Inversion

Results of Investigation

DC Resistivity

Line 1

Lines 2a and 2b

Line 3

Line 4

Three-Dimensional Grid

Line 5

Line 6

Line 7

Electromagnetic Induction

Summary and Discussion


References Cited

Appendix A. DC Resistivity Pseudosections

Appendix B. Digital Data

Accessibility FOIA Privacy Policies and Notices logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Contact USGS
Page Last Modified: Wednesday, December 07, 2016, 11:35:14 PM