FFY2023 chena field-geologic mapping projectproject period: 6 1 2023 through 5 31 2026THE yukon-tanana upland contains many distinct, overlapping mineral systems, such as metamorphic,…

The Alaska Department of Natural Resources (DNR) received a $1,575,000 cooperative agreement award from the U.S. Geological Survey under the Earth Mapping Resources Initiative program to complete modern 1:100,000-scale geologic mapping, geochemistry, and geochronology in parts of four U.S. Geological Survey quadrangle maps located in Alaska. Through this three-year award ending May 2026, DNR will build upon ongoing collaborative efforts with the USGS to upgrade geologic data in Alaska's Yukon-Tanana Upland region. Key deliverables will include a two-dimensional, digital bedrock geologic map using Geologic Map Schema along with correlated map units, a cross section, unit descriptions, and geochemical and field data. This work aims to further characterize Cretaceous intrusive complexes and associated critical mineralization, and refine the structural framework—contributing to improved mineral prospectivity analysis and resource assessment in Alaska.

FFY2023 chena field-geologic mapping projectproject period: 6 1 2023 through 5 31 2026THE yukon-tanana upland contains many distinct, overlapping mineral systems, such as metamorphic, magmatic-hydrothermal, and orthomagmatic systems, that are all prospective for a variety of base, precious, and critical minerals. However, the distribution of these systems and their critical mineral enrichments in the upland are variable and remain incompletely mapped and poorly described. This proposal focuses on key areas with the greatest overlap between multiple mineral systems with associated critical mineral enrichments and outlines key features that relate to critical mineral enrichments in diverse geologic environments. Identifying salient features in these complex systems that influence where, how, and why critical minerals are enriched in mineral systems lays the groundwork for higher-quality, data-driven prospectively and mineral assessment work and provides an updated, data-rich framework for planning and conducting MRP and earth MRI geological mapping and research. The proposed FFY2023 chena field-geologic mapping project will build on ongoing USGS and department of natural resources division of geological geophysical surveys (dggs) collaborative efforts to upgrade geologic data in the YTU. The primary objectives are to: complete modern 1:100,000-scale geologic mapping, geochemistry, and geochronology in parts of the big delta, circle, fairbanks, and charley river quadrangles. The dgds mapping campaign will parse and further characterize the cretaceous intrusive complexes in the region. IT will establish context for SN, w, and REE mineralization and evaluate the area for undiscovered tin granites and peralkaline intrusions among the area s numerous cretaceous granitic bodies. Dgds will use mapping, geochemistry, and geochronology to capture the region s complete mesozoic-cenozoic magmatic history, which will increase understanding of the distribution of igneous rocks with potential to host undiscovered critical minerals. Dgds will build upon USGS work refining the structural subdivisions and assembly of paleozoic metamorphic units (e.g., dusel-bacon and others, 2006). Geologic mapping (day and others, 2003 day and others, 2007 werdon and others, 2004) indicates that both low-angle and high-angle fault systems traverse the proposed map area this work will seek to validate these structures on the ground and to map geological relationships that constrain their timing and displacement.deliverables: within three years of receipt of funding, dggs will produce a two-dimensional, digital, bedrock geologic map at 1:100,000 scale using gems schema. Deliverables will include a PDF map layout, browse image, fgdc metadata, file geodatabase, arcmap .MXD document, and associated resources. The map will include a correlation of map units, cross section, and unit descriptions. Station locations including field notes, structural measurements, and completed geochronology will be delivered within the gems file geodatabase. New geochemical data will be RE-analyzed by the USGS contract laboratory and published through dggs and USGS.