Virginia Energy is working in partnership with the U.S. Geological Survey Earth Mapping Resources Initiative (Earth MRI) to create maps that will stimulate domestic exploration for mineral resources critical to U.S. security and economic prosperity. This work is designed to support the goals of Federal Executive Order 13817 to strengthen and sustain our Nation's critical mineral supply chains. The Earth MRI Program seeks to "improve topographic, geologic, and geophysical mapping of the United States and make the resulting data and metadata electronically accessible". For a snapshot of all of the federally-funded projects supported through the program, check out their Earth MRI Acquisitions Viewer.

Virginia Energy recently completed two heavy mineral placer studies along the eastern Piedmont and western Coastal Plain of Virginia. These project areas as known as the Earth MRI Placer Ti-Zr-REE Virginia Focus Area. This work was implemented in two phases of work: Phase 1, which consists of four project areas in the Fall Zone and Coastal Plain (Fiscal Year 2019-2020), and Phase 2, five 7.5-minute quadrangles located along and just west of the Fall Zone in the Eastern Piedmont of Virginia.

Existing geochemical and geophysical datasets provided insights into anomalies associated with titanium, zirconium, and rare earth element (REE) bearing deposits. Historical mining operations in the vicinity of Stony Creek and Emporia, VA also provided rationale for new data collection needs. Recently, Atlantic Strategic Minerals have resumed a new mineral sands operation within the Old Hickory deposit, the formerly mined paleoplacer deposit (https://www.atlanticstrategicminerals.com/).

The Earth MRI initiative has also supported and fostered increased collaboration between neighboring state geological surveys and the USGS for regional mineral and geochemical resource assessments. The North Carolina Geological Survey is leading an effort to characterize REE mobilization and enrichment in granitoid regolith in the southeastern U.S. Virginia and South Carolina are partnering with North Carolina to assess granitoid plutons across the Piedmont province that may have similar characteristics to known ion clay adsorption deposits in China, where the majority of the heavy rare earth elements (HREE) are sourced from. This study is novel for the U.S. and Virginia and can serve as a model for potential domestic HREE occurrences.

Geologists have also focused on the potential for critical minerals to exist in mine waste across the Commonwealth. We recently completed an inventory mine waste sites including mine tailings and piles that could host critical minerals based on their historical mining operations. More information on this effort is provided in the Current Work section.

Goals

Strengthening the critical mineral supply chain - Placer  deposits of heavy minerals that occur in unconsolidated fluvial and nearshore sediments in the inner Coastal Plain of Virginia are a proven economic resource for titanium (Ti), zirconium (Zr), and rare earth elements (REE) (Berquist and others, 2015; Bern and others, 2016; Shah and others, 2017). These commodities are among those identified by the USGS in 2018 as "essential to the economic and national security of the United States (Fortier and others, 2018). The critical commodities are concentrated in heavy minerals such as ilmenite, rutile, leucoxene, zircon, and monazite. These minerals occur in trace amounts in late Proterozoic- to Paleozoic-age igneous and metamorphic rocks in the eastern Piedmont, and once liberated by weathering, can be concentrated in sediments due to their relatively high specific gravity (2.9 g/cm³). Igneous bedrock sources in proposed mapping areas also have the potential for hosting residual deposits of economic minerals in clay-rich regolith, concentrated by chemical weathering processes. A major objective of these projects is to gain a better understanding of the geologic processes that influence geochemical mobility, transport, and concentration of economic critical minerals. We expect to provide new geologic and geochemical data that will lead to exploration by the private sector.

Improving geologic map coverage - The best available geologic map for a large portion of Virginia's Coastal Plain is the 1:250,000-scale geologic map by Mixon and others (1989). While this map is an excellent resource, it does not provide sufficient detail for many needed decisions related to public safety, environmental protection, and economic development. Since 2000, Virginia has worked through the National Cooperative Geologic Mapping Program, STATEMAP component to improve the availability of detailed geologic maps. This effort has resulted in a new 1:100,000-scale geologic map of the Williamsburg 30- x 60-minute quadrangle (Berquist, 2013) and thirteen 1:24,000-scale geologic quadrangle maps. In addition, two quadrangles in the Petersburg area were mapped in cooperation with the National Park Service (Occhi and others, 2018). Despite this effort, significant areas in the Coastal Plain lack 1:100,000-scale or better map coverage. As part of the new mapping efforts, we compiled new 1:100,000-scale geologic maps for target project areas identified in the Earth MRI Placer Ti-Zr-REE deposits, Virginia Focus Area. These digital map products will result in improved map availability in the Earth MRI critical minerals resource focus area. Newly acquired airborne magnetic and radiometric surveys across the Fall Zone of Virginia and Eastern Piedmont have helped Geologists in new mapping efforts as well as in the evaluation of potential economic deposits. More information of the USGS airborne geophysical efforts can be found within their Earth MRI acquisitions viewer page.

Making geologic data electronically available - Most published geologic maps in the Coastal Plain are only available in hard copy format. Some recent maps are available in GIS, with formats ranging from separate shapefiles with minimal attribution to fully attributed NCGMP09 geodatabases. Geologic Map Schema (GeMS) compliant databases (formerly NCGMP09) have been created for the Phase 1 and Phase 2 project areas. These maps and geodatabases are available to the public with complete metadata. The geodatabases also support the planned 1:100,000-scale geologic maps and geodatabases of the Emporia 30- x 60-minute quadrangle and the Richmond metropolitan area. The GeMS geodatabase compilations will support the USGS objective to create a three-dimensional (3-D) digital geologic map of the United States.

Current Work

Earth MRI Virginia Placer Area (FY19-20) - Phase 1
USGS Grant No. G19AC00260 - Status: Completed

Four project areas located in the Virginia Coastal Plain were targeted based on National Uranium Resource Evaluation (NURE) radiometric equivalent thorium (eTh) geophysical anomalies and NURE stream sediment data (i.e. hafnium) (Figure 1). The project areas overlay and cross-cut 24 different quadrangles at variable extents, and range in size from approximately 84 to 282 square kilometers. The four areas extend from the Virginia Fall Zone eastward into the Atlantic Coastal Plain.

Virginia Energy compiled existing geologic maps and conducted new geologic mapping and sampling in the project areas. We produced 1:100,000-scale geologic maps and a GeMS Level-2 compliant geodatabase. The geologic maps display surficial geology throughout the project areas, sample locations, mineral resources, cross-sections, and provide a full explanation of geologic units. Additionally, 29 auger grab samples and 24 stream sediment samples were collected to characterize geologic units and assess the likelihood for economic mineral occurrences.

PDF copies of the geologic maps, a GeMS geodatabase, and a technical open-file report are avaialbel in the Virginia Energy web store.

Sample Locations (FY19-20):

Sample Location Pictures (PDF)

Earth MRI Virginia Placer Area (FY21-22) - Phase 2
USGS Grant No. G21AC10499 - Status: Completed, Pending USGS Review

The second phase of the Earth MRI includes the compilation of geologic map data in five 7.5-minute quadrangles located along and just west of the Virginia Fall Zone. The goal of this phase is to expand the 1:100,000-scale geologic mapping into additional areas that are prospective for critical mineral resources. The second phase was completed in 2024, and these data products will be uploaded to our webstore in early 2025.

Field Methods Implemented

A major objective of these projects is to provide detailed geologic map coverage and analytical analyses for samples that may host critical minerals. Due to the lack of outcrop exposures in the Coastal Plain of Virginia, geologic mapping commonly involves the use a drill rig to obtain subsurface samples from depth to characterize the lithology and correlate units across the map area. Many grab samples were collected via a stainless-steel hand auger or from drill rig auger cuttings for geochemical and mineralogical analyses. To evaluate the economic mineral fractions of grab and stream sediment samples, we concentrated heavier minerals via gravity separation using a three-turn Humphrey spiral. These concentrated samples represent the total heavy mineral (THM) fraction of the bulk samples. These samples were submitted to an analytical laboratory, where they were further concentrated by heavy liquid separation and analyzed to obtain detailed mineralogy on the respective THM fractions.

Click here to see a video of mineral separation in the Humphrey Spiral. Darker minerals are entrained in the water flow to the right of the splitter and lighter minerals such as quartz are to the left of the splitter

Characterization of REE in Regolith - Earth MRI NC-SC-VA Joint Initiative

USGS Grant No. G23AC00459 - Status: In Progress, anticipated completion in 2026

The North Carolina Geological Survey is leading a multi-state effort to characterize the potential for REE to occur within weathered regolith that occurs above Alleghanian and NeoAcadian aged granitoids in the Piedmont. This collaborative involves the South Carolina Geological Survey and Virginia, and field sampling events are underway as of early 2025. Numerous granitoids are present in the Central and Eastern Piedmont of Virginia that may host enriched REE within the regolith profile, which extends from the base of the weathered rock up through the saprolite and soil profiles. We are accomplishing sampling via multiple methods including collection of cores via direct-push technology drilling methods and sampling of existing in-situ exposures.

Mine Waste Inventory

USGS Grant No. G23AC00522 - Status: Completed

Virginia Energy's Geology and Minerals Resources and Mineral Mining Programs completed a statewide inventory of mine waste piles (greater than 2,000 square meters) that may have potential to host critical minerals, as byproducts of historical mining. The purpose of this inventory is to inform future land management, planning, and remediation decisions in Virginia by identifying nonfuel mine waste sites that may contain critical mineral resources. Records were compiled into a geodatabase following a USGS provided framework. We anticipate applying for future funds to begin a second phase of assessment involving the characterization of waste piles from an existing or historical mine site.