Airborne Geophysics for Rare Earth Element Deposits (AGREED)

Map showing study locations. Principal rare earth elements districts in the United States and location of high resolution geophysical surveys flown by industry and planned surveys (stars). (Long and others, 2010, USGS SIR 2010-5220).

Over two dozen rare earth element (REE) deposits have been identified both in the conterminous U.S. (Long and others, 2010) and in Alaska (Barker and Van Gosen, 2010). The majority of larger U.S. deposits are hosted in carbonatite or peralkaline intrusions and related pegmatites and veins, which typically make excellent geophysical targets because of their distinct gamma ray, density, and magnetic properties. As such, airborne geophysical surveying is routinely acquired by industry to map the extent of surface and subsurface mineralization related to these deposits. In many cases, geophysical surveying has figured prominently in the initial discovery of REE deposits.

The USGS AGREED project is coordinating with industry to use high resolution airborne geophysical data collected over some of the advanced REE projects in the U.S. These data are being analyzed, interpreted and modeled so that a better understanding of the REE deposits' geologic setting, framework, and ore genesis can be generated. In addition, the project will create a petrophysical library of samples collected from these deposits that will contribute to and compliment the airborne geophysical analyses. Learn more about the project.