Alaska is dominated by a history of tectonic events that foster mobilization and concentration of a wide variety of mineral commodities that are critical to the US economy and are vital to national defense, renewable-energy, and emerging electronics technologies.
Return to Geology

The project’s current objective is to quantify and understand the distribution of critical elements in ore-forming systems in Alaska. It uses a recently developed, data-driven geographic information system (GIS)-based method to evaluate the potential of various mineral deposit types across the state of Alaska. The method systematically analyzes pre-existing, geospatially referenced datasets to generate a map, which provides a visual indication of the estimated potential (high, medium, low) and the certainty of that estimate (high, medium, low) for each watershed in Alaska for a mineral commodity, mineral deposit type, or group of mineral deposit types. Probabilities are calculated with set criteria based on lithology, geochemistry, and geophysical data. The datasets used include the USGS Alaska Geochemical Database, the Alaska Division of Geological and Geophysical Surveys web-based geochemical database, data from the USGS geologic map of Alaska, the USGS Alaska Resource Data File, USGS airborne magnetic surveys, and radiometric surveys from the National Uranium Resource Evaluation.
GIS-based method
The GIS-based method applies a scoring system to geospatially referenced geologic data in subwatersheds, which are hydrologic units defined by the National Hydrography Dataset and Watershed Boundary Dataset. The scoring system uses multiple parameters based on key characteristics specific to each deposit type. The key characteristics are chosen based on known occurrences of the mineral in deposits around the world, known occurrences in Alaska, and previous research relating to the geologic processes responsible for the formation of these deposit types. Each deposit type has uniquely defined parameters and different point values assigned to the parameters. The parameters are then scored and weighted for each of the different mineral deposit types to generate a score for potential for a concentration of the mineral or deposit type in each watershed. These scores are classified using natural statistical breaks and assigned colors for each watershed for portrayal on maps as shown in the figure: high (red), medium (yellow), low (green), or unknown (gray, owing to lack of data) potential. The confidence or certainty of the score is then calculated taking into consideration factors such as quantity of data and completeness of the datasets. Levels of confidence are shown as dark (high), medium (medium), or light (low) shades of red, yellow, or green, respectively, for each watershed on the maps.
As an example, the scoring system for placer gold deposits uses five parameters: pan concentrate mineralogy, sediment geochemistry, rock type, geographical location, and whether the Alaska Resource Data File has any reports for the specific area mentioning placer gold as a keyword. Each parameter has a set number of possible points which allows for the parameters to weigh in differently to the total score. For example, pan concentrate data were assigned point values of up to 10, while the presence of plutonic rocks in the watershed could be assigned a maximum of 3 points. In other words, the presence of gold in pan concentrate data indicates a high probability of finding gold in the area; however the presence of plutonic rocks in an area may often, but not always, correlate with placer gold deposits, and thus carries less weight in the overall score. After each parameter is assigned a score and a total score is calculated for each watershed, the certainty of the overall score is determined based on the number of datasets that contributed to the score for each of the parameters in that watershed.
The method is highly adaptable for the needs of diverse users, including scientific researchers, industry, land mangers such as the Bureau of Land Management and the State of Alaska, and Alaska Native corporations. Examples of how this GIS analysis can be applied include:
- Identification of areas with high mineral potential supported by abundant data
- Identification of understudied and undersampled prospective areas
- Topical investigations to improve current deposit models
- Development and modification of resource evaluation techniques
- Identification and recognition of new pathfinders and different types of data combinations linked to processes of ore genesis
- Constraint or expansion of the footprint of known mineral belts
- Discovery and definition of new mineral trends or belts
This project is a continuation of the Alaska Critical Minerals Cooperative Project.
Below are other science projects associated with this project.
Alaska Resource Data File
Alaska Critical Minerals Cooperative
Below are data releases and webtools associated with this project.
Data for Uranium-Lead Geochronology, Carbon and Sulfur Stable Isotopes, and Raman Spectroscopy from Graphite Creek, Alaska
Data from the Chemical Analysis of Archived Stream-Sediment Samples, Alaska
Data and results for GIS-based identification of areas that have resource potential for lode gold deposits in Alaska
Below are publications associated with this project.
Insights into the metamorphic history and origin of flake graphite mineralization at the Graphite Creek graphite deposit, Seward Peninsula, Alaska, USA
Alaska Geochemical Database Version 3.0 (AGDB3)—Including “Best Value” Data Compilations for Rock, Sediment, Soil, Mineral, and Concentrate Sample Media
Geospatial analysis identifies critical mineral-resource potential in Alaska
GIS-based identification of areas that have resource potential for critical minerals in six selected groups of deposit types in Alaska
GIS-Based Identification of Areas with Mineral Resource Potential for Six Selected Deposit Groups, Bureau of Land Management Central Yukon Planning Area, Alaska
Below are partners associated with this project.
- Overview
Alaska is dominated by a history of tectonic events that foster mobilization and concentration of a wide variety of mineral commodities that are critical to the US economy and are vital to national defense, renewable-energy, and emerging electronics technologies.
Return to Geology
Sources/Usage: Public Domain. Visit Media to see details.Estimated mineral-resource potential and levels of certainty, indicated by shading of colors, for rare earth elements, thorium, yttrium, niobium, uranium, and zirconium in alkaline igneous rocks.(Credit: Keith Labay, U.S. Geological Survey. Public domain.) The project’s current objective is to quantify and understand the distribution of critical elements in ore-forming systems in Alaska. It uses a recently developed, data-driven geographic information system (GIS)-based method to evaluate the potential of various mineral deposit types across the state of Alaska. The method systematically analyzes pre-existing, geospatially referenced datasets to generate a map, which provides a visual indication of the estimated potential (high, medium, low) and the certainty of that estimate (high, medium, low) for each watershed in Alaska for a mineral commodity, mineral deposit type, or group of mineral deposit types. Probabilities are calculated with set criteria based on lithology, geochemistry, and geophysical data. The datasets used include the USGS Alaska Geochemical Database, the Alaska Division of Geological and Geophysical Surveys web-based geochemical database, data from the USGS geologic map of Alaska, the USGS Alaska Resource Data File, USGS airborne magnetic surveys, and radiometric surveys from the National Uranium Resource Evaluation.
GIS-based method
The GIS-based method applies a scoring system to geospatially referenced geologic data in subwatersheds, which are hydrologic units defined by the National Hydrography Dataset and Watershed Boundary Dataset. The scoring system uses multiple parameters based on key characteristics specific to each deposit type. The key characteristics are chosen based on known occurrences of the mineral in deposits around the world, known occurrences in Alaska, and previous research relating to the geologic processes responsible for the formation of these deposit types. Each deposit type has uniquely defined parameters and different point values assigned to the parameters. The parameters are then scored and weighted for each of the different mineral deposit types to generate a score for potential for a concentration of the mineral or deposit type in each watershed. These scores are classified using natural statistical breaks and assigned colors for each watershed for portrayal on maps as shown in the figure: high (red), medium (yellow), low (green), or unknown (gray, owing to lack of data) potential. The confidence or certainty of the score is then calculated taking into consideration factors such as quantity of data and completeness of the datasets. Levels of confidence are shown as dark (high), medium (medium), or light (low) shades of red, yellow, or green, respectively, for each watershed on the maps.
As an example, the scoring system for placer gold deposits uses five parameters: pan concentrate mineralogy, sediment geochemistry, rock type, geographical location, and whether the Alaska Resource Data File has any reports for the specific area mentioning placer gold as a keyword. Each parameter has a set number of possible points which allows for the parameters to weigh in differently to the total score. For example, pan concentrate data were assigned point values of up to 10, while the presence of plutonic rocks in the watershed could be assigned a maximum of 3 points. In other words, the presence of gold in pan concentrate data indicates a high probability of finding gold in the area; however the presence of plutonic rocks in an area may often, but not always, correlate with placer gold deposits, and thus carries less weight in the overall score. After each parameter is assigned a score and a total score is calculated for each watershed, the certainty of the overall score is determined based on the number of datasets that contributed to the score for each of the parameters in that watershed.
The method is highly adaptable for the needs of diverse users, including scientific researchers, industry, land mangers such as the Bureau of Land Management and the State of Alaska, and Alaska Native corporations. Examples of how this GIS analysis can be applied include:
- Identification of areas with high mineral potential supported by abundant data
- Identification of understudied and undersampled prospective areas
- Topical investigations to improve current deposit models
- Development and modification of resource evaluation techniques
- Identification and recognition of new pathfinders and different types of data combinations linked to processes of ore genesis
- Constraint or expansion of the footprint of known mineral belts
- Discovery and definition of new mineral trends or belts
This project is a continuation of the Alaska Critical Minerals Cooperative Project.
- Science
Below are other science projects associated with this project.
Alaska Resource Data File
The Alaska Resource Data File (ARDF) site provides descriptions of mines, prospects, and mineral occurrences for individual U.S. Geological Survey 1:250,000-scale quadrangles in Alaska.Alaska Critical Minerals Cooperative
The project developed means to use several large legacy digital databases together in GIS to identify areas with mineral resource potential for critical minerals in Alaska. - Data
Below are data releases and webtools associated with this project.
Data for Uranium-Lead Geochronology, Carbon and Sulfur Stable Isotopes, and Raman Spectroscopy from Graphite Creek, Alaska
This data release supports the paper titled, "Insights into the metamorphic history and origin of flake graphite mineralization at the Graphite Creek graphite deposit, Seward Peninsula, Alaska, USA", published in the journal Mineralium Deposita. The data release includes zircon and titanite U-Pb-Thisotope and age data, monazite U-Pb-Th isotope, trace element and age data, carbon and sulfur stableiData from the Chemical Analysis of Archived Stream-Sediment Samples, Alaska
This data release contains the elemental concentration data for more than 1700 archived stream-sediment samples collected in Alaska. Samples were retrieved from the USGS Mineral Program's sample archive in Denver, CO, and the Alaska Division of Geological and Geophysical Surveys Geologic Materials Center in Anchorage, AK. All samples were analyzed using a multi-element analytical method involvingData and results for GIS-based identification of areas that have resource potential for lode gold deposits in Alaska
This data release contains the analytical results and evaluated source data files of geospatial analyses for identifying areas in Alaska that may be prospective for different types of lode gold deposits, including orogenic, reduced-intrusion-related, epithermal, and gold-bearing porphyry. The spatial analysis is based on queries of statewide source datasets of aeromagnetic surveys, Alaska Geochemi - Publications
Below are publications associated with this project.
Insights into the metamorphic history and origin of flake graphite mineralization at the Graphite Creek graphite deposit, Seward Peninsula, Alaska, USA
Graphite Creek is an unusual flake graphite deposit located on the Seward Peninsula, Alaska, USA. We present field observations, uranium-lead (U–Pb) monazite and titanite geochronology, carbon (C) and sulfur (S) stable isotope geochemistry, and graphite Raman spectroscopy data from this deposit that support a new model of flake graphite ore genesis in high-grade metamorphic environments. The GraphAuthorsGeorge N. D. Case, Susan M. Karl, Sean P. Regan, Craig A. Johnson, Eric T Ellison, Jonathan Caine, Christopher Holm-Denoma, Laura Pianowski, Jeff A. BenowitzAlaska Geochemical Database Version 3.0 (AGDB3)—Including “Best Value” Data Compilations for Rock, Sediment, Soil, Mineral, and Concentrate Sample Media
The Alaska Geochemical Database Version 3.0 (AGDB3) contains new geochemical data compilations in which each geologic material sample has one “best value” determination for each analyzed species, greatly improving speed and efficiency of use. Like the Alaska Geochemical Database Version 2.0 before it, the AGDB3 was created and designed to compile and integrate geochemical data from Alaska to facilAuthorsMatthew Granitto, Bronwen Wang, Nora B. Shew, Susan M. Karl, Keith A. Labay, Melanie B. Werdon, Susan S. Seitz, John E. HoppeGeospatial analysis identifies critical mineral-resource potential in Alaska
Alaska consists of more than 663,000 square miles (1,717,000 square kilometers) of land—more than a sixth of the total area of the United States—and large tracts of it have not been systematically studied or sampled for mineral-resource potential. Many regions of the State are known to have significant mineral-resource potential, and there are currently six operating mines in the State along withAuthorsSusan M. Karl, Keith A. LabayGIS-based identification of areas that have resource potential for critical minerals in six selected groups of deposit types in Alaska
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 certaintGIS-Based Identification of Areas with Mineral Resource Potential for Six Selected Deposit Groups, Bureau of Land Management Central Yukon Planning Area, Alaska
This study, covering the Bureau of Land Management (BLM) Central Yukon Planning Area (CYPA), Alaska, was prepared to aid BLM mineral resource management planning. Estimated mineral resource potential and certainty are mapped for six selected mineral deposit groups: (1) rare earth element (REE) deposits associated with peralkaline to carbonatitic intrusive igneous rocks, (2) placer and paleoplacerAuthorsJames V. Jones, Susan M. Karl, Keith A. Labay, Nora B. Shew, Matthew Granitto, Timothy S. Hayes, Jeffrey L. Mauk, Jeanine M. Schmidt, Erin Todd, Bronwen Wang, Melanie B. Werdon, Douglas B. Yager - News
- Partners
Below are partners associated with this project.