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GIS-based identification of areas that have resource potential for critical minerals in six selected groups of deposit types in Alaska

Open-File Report 2016-1191
Prepared in cooperation with the Alaska Division of Geological & Geophysical Surveys
Edited by: Susan M. Karl, James V. Jones III, and Timothy S. Hayes
https://doi.org/10.3133/ofr20161191

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Abstract

Alaska has considerable potential for undiscovered mineral resources. This report evaluates potential for undiscovered critical minerals in Alaska. Critical minerals are those for which the United States imports more than half of its total supply and which are largely derived from nations that cannot be considered reliable trading partners. In this report, estimated resource potential and certainty for the state of Alaska are analyzed and mapped for the following six selected mineral deposit groups that may contain one or more critical minerals: (1) rare earth elements-thorium-yttrium-niobium(-uranium-zirconium) [REE-Th-Y-Nb(-U-Zr)] deposits associated with peralkaline to carbonatitic igneous intrusive rocks; (2) placer and paleoplacer gold (Au) deposits that in some places might also produce platinum group elements (PGE), chromium (Cr), tin (Sn), tungsten (W), silver (Ag), or titanium (Ti); (3) platinum group elements(-cobalt-chromium-nickel-titanium-vanadium) [PGE(-Co-Cr-Ni-Ti-V)] deposits associated with mafic to ultramafic intrusive rocks; (4) carbonate-hosted copper(-cobalt-silver-germanium-gallium) [Cu(-Co-Ag-Ge-Ga)] deposits; (5) sandstone-hosted uranium(-vanadium-copper) [U(-V-Cu)] deposits; and (6) tin-tungsten-molybdenum(-tantalum-indium-fluorspar) [Sn-W-Mo(-Ta-In-fluorspar)] deposits associated with specialized granites.

This study used a data-driven, geographic information system (GIS)-implemented method to identify areas that have mineral resource potential in Alaska. This method systematically and simultaneously analyzes geoscience data from multiple geospatially referenced datasets and uses individual subwatersheds (12-digit hydrologic units) as the spatial unit of classification. The final map output uses a red, yellow, green, and gray color scheme to portray estimated relative potential (High, Medium, Low, Unknown) for each of the six groups of mineral deposit types, and it indicates the relative certainty (High, Medium, Low) of that estimate for each 12-digit hydrologic unit through color shading. Accompanying tables describe the data layers employed to score favorability for the presence of each mineral deposit group, the values assigned for specific analysis parameters, and the relative weighting of each data layer that contributes to estimated measures of potential and certainty. Core datasets used include the Alaska Geochemical Database, Version 2.0 (AGDB2); the Alaska Division of Geological & Geophysical Surveys (ADGGS) web-based geochemical database; the digital “Geologic Map of Alaska;” the Alaska Resource Data File (ARDF); and aerial gamma-ray surveys flown as part of the National Uranium Resource Evaluation (NURE) Program by the U.S. Department of Energy.

Maps accompanying this report illustrate the scores for estimated mineral resource potential for the six deposit groups for the state of Alaska. Areas that have known potential, as well as new areas that were not previously known to have potential, for the targeted minerals and deposit groups are identified and described. Numerous areas in Alaska, some of them large, have high potential for one or more of the selected groups of deposit types within Alaska.

Contributors

Matthew Granitto, Timothy S. Hayes, James V. Jones, III, Susan M. Karl, Keith A. Labay, Jeffrey L. Mauk, Jeanine M. Schmidt, Nora B. Shew, Erin Todd, Bronwen Wang, Melanie B. Werdon, and Douglas B. Yager

Suggested Citation

Karl, S.M., Jones, J.V., III, and Hayes, T.S., eds., 2016, GIS-based identification of areas that have resource potential for critical minerals in six selected groups of deposit types in Alaska: U.S. Geological Survey Open-File Report 2016–1191, 99 p., 5 appendixes, 12 plates, scale 1:10,500,000, http://dx.doi.org/10.3133/ofr20161191.

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Abstract
  • Introduction
  • Chapter 1. REE-Th-Y-Nb(-U-Zr) Deposits Associated with Peralkaline to Carbonatitic Intrusive Rocks
  • Chapter 2. Placer and Paleoplacer Gold (Au) Deposits
  • Chapter 3. PGE(-Co-Cr-Cu-Ni-Ti-V) Deposits Associated with Mafic to Ultramafic Intrusive Rocks
  • Chapter 4. Carbonate-Hosted Cu(-Co-Ag-Ge-Ga) Deposits
  • Chapter 5. Sandstone-Hosted U(-V-Cu) Deposits
  • Chapter 6. Sn-W-Mo(-Ta-In-Fluorspar) Deposits Associated with Specialized Granites
  • Summary
  • Data Resources
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title GIS-based identification of areas that have resource potential for critical minerals in six selected groups of deposit types in Alaska
Series title Open-File Report
Series number 2016-1191
DOI 10.3133/ofr20161191
Year Published 2016
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Alaska Science Center Geology Minerals
Description Report: viii, 99 p.; 12 Plates: 12 p.; 8 Appendixes; Metadata
Country United States
State Alaska
Online Only (Y/N) Y
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details