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Erik R. Tharalson, Ph.D.

Erik Tharalson is a Research Geologist with the Geology, Geophysics, and Geochemistry Science Center.
 

Erik’s research centers on understanding the formation and distribution of mineral resources through the study of magmatic and hydrothermal processes. He integrates field geology, geochemistry, and structural geology to define the frameworks that control ore deposit formation. His work focuses primarily on magmatichydrothermal systems in the western United States.

Professional Experience

  • U.S. Geological Survey, 2024 - present

Education and Certifications

  • PhD, Geology, Colorado School of Mines, 2021

  • MSc, Geology, Colorado School of Mines, 2012

  • BSc, Geology, University of Minnesota, Duluth, 2008

Affiliations and Memberships*

  • Society of Geology Applied to Mineral Deposits

  • Society of Economic Geologists

  • Geological Society of America

Science and Products

Image shows a map and key of the United States with mineral locations marked with colored shapes

Critical Minerals Mapping Initiative (CMMI)

The USGS, in combination with Geoscience Australia and the Geological Survey of Canada, formed the Critical Minerals Mapping Initiative (CMMI) in 2019 to combine expertise and collaboratively conduct research on critical mineral resources.
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
Critical Minerals Mapping Initiative (CMMI)

Critical Minerals Mapping Initiative (CMMI)

The USGS, in combination with Geoscience Australia and the Geological Survey of Canada, formed the Critical Minerals Mapping Initiative (CMMI) in 2019 to combine expertise and collaboratively conduct research on critical mineral resources.
Learn More

Data release accompanying quantitative mineral resource assessment of lithium pegmatite deposits in the Northern Appalachian Orogen, USA Data release accompanying quantitative mineral resource assessment of lithium pegmatite deposits in the Northern Appalachian Orogen, USA

The area of study is restricted to the northern Appalachian region between latitudes 38N and 48N and longitudes 66W and 77W in the U.S. states of Maine, New Hampshire, Vermont, New York, Massachusetts, Connecticut, Rhode Island, Pennsylvania, and Delaware. This study (Wintzer and others, 2025) integrates data from several sources, including geologic, geochemical, geophysical, watershed...
By
Geology, Minerals, Energy, and Geophysics Science Center

Domestic and international rock geochemistry of ore and host rocks generated by the Critical Minerals Mapping Initiative Domestic and international rock geochemistry of ore and host rocks generated by the Critical Minerals Mapping Initiative

Geochemical data included were generated as part of the Critical Minerals Mapping Initiative (CMMI). Individual samples are classified according to the Hofstra et al. (2021) CMMI deposit classification scheme. The goal of CMMI is to collaborate with Geoscience Australia and the Geological Survey of Canada to build a global database of critical minerals in a variety of ore deposits. The...
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Assessing United States gallium and germanium resources in basin-hosted deposits – The good and bad Assessing United States gallium and germanium resources in basin-hosted deposits – The good and bad

Basin-hosted Zn-Pb deposits, including MVT and clastic-dominated (CD or “Sedex”) Zn-Pb deposits are major sources of Zn and Pb, as well as other critical elements. We examined available whole rock and sphalerite chemistry data to understand the apparent variation of Ga and Ge among major current and historical districts of the United States (US). Robust data from the Central Tennessee...
Authors
Garth E. Graham, Erik Roger Tharalson
By
Geology, Geophysics, and Geochemistry Science Center

Low-sulfidation epithermal deposits of the central Basin and Range Province, USA Low-sulfidation epithermal deposits of the central Basin and Range Province, USA

The Basin and Range Province is host to many important low-sulfidation epithermal deposits. Within this broad zone of extension, epithermal deposits are hosted by specific areas of Miocene and younger bimodal volcanism. In northern Nevada, rifting and related volcanic activity occurred in response to thermal bulging during the development of the Yellowstone hotspot. The Colorado River...
Authors
Thomas Monecke, Lauren R. Terry, Erik Roger Tharalson, T. James Reynolds, Greg Seitter, Tadsuda Taksavasu, Eric Anderson
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Non-USGS Publications**

Tharalson, Erik R., Takasavasu, Tadsuda, Monecke, Thomas, Reynolds, T. James, Kelly, Nigel M., Pfaff, Katharina, Bell, Aaron S., and Sherlock, Ross, 2023, Textural characteristics of ore mineral dendrites in banded quartz veins from low-sulfidation epithermal deposits: implications for the formation of bonanza-type precious metal enrichment: Mineralium Deposita, 58, p. 1395-1419, https://doi.org/10.1007/s00126-023-01187-7.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

Science and Products

Image shows a map and key of the United States with mineral locations marked with colored shapes

Critical Minerals Mapping Initiative (CMMI)

The USGS, in combination with Geoscience Australia and the Geological Survey of Canada, formed the Critical Minerals Mapping Initiative (CMMI) in 2019 to combine expertise and collaboratively conduct research on critical mineral resources.
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
Critical Minerals Mapping Initiative (CMMI)

Critical Minerals Mapping Initiative (CMMI)

The USGS, in combination with Geoscience Australia and the Geological Survey of Canada, formed the Critical Minerals Mapping Initiative (CMMI) in 2019 to combine expertise and collaboratively conduct research on critical mineral resources.
Learn More

Data release accompanying quantitative mineral resource assessment of lithium pegmatite deposits in the Northern Appalachian Orogen, USA Data release accompanying quantitative mineral resource assessment of lithium pegmatite deposits in the Northern Appalachian Orogen, USA

The area of study is restricted to the northern Appalachian region between latitudes 38N and 48N and longitudes 66W and 77W in the U.S. states of Maine, New Hampshire, Vermont, New York, Massachusetts, Connecticut, Rhode Island, Pennsylvania, and Delaware. This study (Wintzer and others, 2025) integrates data from several sources, including geologic, geochemical, geophysical, watershed...
By
Geology, Minerals, Energy, and Geophysics Science Center

Domestic and international rock geochemistry of ore and host rocks generated by the Critical Minerals Mapping Initiative Domestic and international rock geochemistry of ore and host rocks generated by the Critical Minerals Mapping Initiative

Geochemical data included were generated as part of the Critical Minerals Mapping Initiative (CMMI). Individual samples are classified according to the Hofstra et al. (2021) CMMI deposit classification scheme. The goal of CMMI is to collaborate with Geoscience Australia and the Geological Survey of Canada to build a global database of critical minerals in a variety of ore deposits. The...
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Assessing United States gallium and germanium resources in basin-hosted deposits – The good and bad Assessing United States gallium and germanium resources in basin-hosted deposits – The good and bad

Basin-hosted Zn-Pb deposits, including MVT and clastic-dominated (CD or “Sedex”) Zn-Pb deposits are major sources of Zn and Pb, as well as other critical elements. We examined available whole rock and sphalerite chemistry data to understand the apparent variation of Ga and Ge among major current and historical districts of the United States (US). Robust data from the Central Tennessee...
Authors
Garth E. Graham, Erik Roger Tharalson
By
Geology, Geophysics, and Geochemistry Science Center

Low-sulfidation epithermal deposits of the central Basin and Range Province, USA Low-sulfidation epithermal deposits of the central Basin and Range Province, USA

The Basin and Range Province is host to many important low-sulfidation epithermal deposits. Within this broad zone of extension, epithermal deposits are hosted by specific areas of Miocene and younger bimodal volcanism. In northern Nevada, rifting and related volcanic activity occurred in response to thermal bulging during the development of the Yellowstone hotspot. The Colorado River...
Authors
Thomas Monecke, Lauren R. Terry, Erik Roger Tharalson, T. James Reynolds, Greg Seitter, Tadsuda Taksavasu, Eric Anderson
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Non-USGS Publications**

Tharalson, Erik R., Takasavasu, Tadsuda, Monecke, Thomas, Reynolds, T. James, Kelly, Nigel M., Pfaff, Katharina, Bell, Aaron S., and Sherlock, Ross, 2023, Textural characteristics of ore mineral dendrites in banded quartz veins from low-sulfidation epithermal deposits: implications for the formation of bonanza-type precious metal enrichment: Mineralium Deposita, 58, p. 1395-1419, https://doi.org/10.1007/s00126-023-01187-7.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government

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