Technical Assistance to Government of Greenland - Hyperspectral Imaging of Critical Mineral Resources

In July 2019, USGS geophysicists Raymond Kokaly and Todd Hoefen and geologist Cliff Taylor provided technical assistance to the government of Greenland, including the collection of field measurements of reflectance and geologic samples with colleagues from the Greenland Department of Geology and the Greenland Survey (Asiaq). These efforts were in support of a planned airborne hyperspectral survey over the Gardar Province in South Greenland, based out of Narsarssuaq. The Greenland Ministry of Mineral Resources and Labour conducted a hyperspectral survey in summer 2019, with assistance from the U.S. Department of State, to improve the geologic and mineralogic knowledge of region. From mid-July through August, the Naval Research Laboratory flew multiple hyperspectral sensors covering the electromagnetic wavelength region of reflected sunlight, from the visible and near-infrared (VNIR) to the shortwave infrared (SWIR). The area covered by the survey included the Ilimassauq intrusion complex, host to deposits and occurrences of critical minerals such as rare-earth elements (REE), tantalum and niobium.

The work is expected to produce a spectral library of rock types and minerals occurring in the rare peralkaline granites. If weather conditions permit, ground-based hyperspectral imaging of mountain sides and outcrop will be performed to map minerals at high spatial resolution. The spectral fingerprints of minerals developed from the fieldwork will be used to calibrate and process the airborne hyperspectral data in order to map mineral distributions over a larger area. Carrying out such work in the arctic is challenging because of the difficulty in accessing remote areas with steep terrain, the relatively weak solar illumination at high latitude, and the likelihood of cloudy skies and severe weather. However, the USGS recently demonstrated the potential utility of hyperspectral imaging for mineral resource studies in Alaska.

From the Greenland work conducted, the spectral measurements and derived mineral maps, in conjunction with existing geologic, geophysical, and geochemical data, will improve understanding of the formation of REE deposits, knowledge of the distribution of mineral resources in southern Greenland, and increase our ability to conduct mineral mapping at high latitude, for example, in places like Alaska.

Return to Spectroscopy Lab | Geology, Geophysics, and Geochemistry Science Center