In the fall of 2014, the North Dakota Geological Survey proposed a rare earth project in their 2015-2017 biennial budget that was subsequently approved during the 2015 legislative session. In September 2015, the Geological Survey began collecting lignite, organic-rich mudstone, and clinker/coal ash samples in western North Dakota for rare earth element analysis. Photographs were taken of each sample interval and coal quality was noted; i.e., highly cleated, moderately cleated, oxidized, etc.
Sampling has been broadly distributed, both geographically and stratigraphically. To date, these investigations have yielded thousands of laboratory-analyzed samples and hundreds of measured geological sections. Through their extensive research, NDGS has gained a rather cohesive explanation for the rare earth element distribution in the Williston Basin and is now able to narrow down the exploration. The specific thickness, lateral extent, depth, and grade of rare earth and other critical element enrichment required for commercialization is still unknown at this time but is the focus of ongoing studies.
The North Dakota Geological Survey has authored numerous reports and articles on rare earth elements and other critical minerals (REE-CM) as observed in the lignites of Western North Dakota.
The updated 2022 list of critical minerals is diverse: aluminum, antimony, arsenic, barite, beryllium, bismuth, cesium, chromium, cobalt, fluorspar, gallium, germanium, graphite, hafnium, indium, iridium, lithium, magnesium, manganese, nickel, niobium, palladium, platinum, rhodium, rubidium, ruthenium, tantalum, tellurium, tin, titanium, tungsten, vanadium, zinc, zirconium, and the sixteen rare earth elements (REE). The rare earths, often included as a group because they are chemically similar and commonly occur together, are often the first example used when discussing critical minerals.
- Critical Minerals Below North Dakota's Oldest Landscapes - Part I, by Levi D. Moxness
NDGS Resources for Rare Earth Elements & Other Critical Minerals
REPORTS OF INVESTIGATION
| RI-134 | Critical Mineral Enrichment In Lignites Beneath The Rhame Bed (Paleocene) Of The Slope Formation In The Williston Basin Of North Dakota, by Moxness, L.D., Murphy, E.C., and Kruger, N.W., 2023. |
| RI-133 | Elevated Critical Mineral Concentrations Associated with the Paleocene-Eocene Thermal Maximum, Golden Valley Formation, North Dakota, by Murphy, E.C., Moxness, L.D., and Kruger, N.W., 2023. |
| RI-131 | Rare Earth and Other Critical Element Concentrations in the Sentinel Butte and Bullion Creek Formations (Paleocene), Billings, McKenzie, and Golden Valley Counties, North Dakota, by Kruger, N.W., Moxness, L.D., and Murphy, E.C., 2022. |
| RI-130 | Critical Minerals in the Fox Hills (Cretaceous), Hell Creek (Cretaceous), and Ludlow (Paleocene) Formations in North Dakota, by Moxness, L.D., Murphy, E.C., and Kruger, N.W., 2022. |
| RI-128 | Rare Earth and Other Critical Element Concentrations in the Sentinel Butte Formation, Tracy Mountain, North Dakota, by Moxness, L.D., Murphy, E.C., and Kruger, N.W., 2021. |
| RI-119 | Rare Earth Element Concentrations in the Harmon, Hanson, and H Lignites in Slope County, North Dakota, by Murphy, E.C., Moxness, L.D., Kruger, N.W., and Maike, C.A., 2018. |
| RI-117 | Rare Earth Element Concentrations in Fort Union and Hell Creek Strata in Western North Dakota, by Kruger, N.W., Moxness L.D., and Murphy, E.C., 2017. |
GEO NEWS ARTICLES
| July 2023 | Critical Minerals Below North Dakota's Ancient Subtropical Soils - Part II, by Moxness, L.D. |
| January 2023 | Critical Minerals Below North Dakota’s Oldest Landscapes - Part I, by Moxness, L.D. |
| July 2022 | Lithium Exploration in the Williston Basin and the Potential of Madison Brine Waters in Western North Dakota, by Nesheim, T.O. |
| January 2021 | Critical Minerals in North Dakota, by Moxness, L.D. |
| January 2021 | Estimating Rare Earth Concentrations, by Kruger, N.W. |
| July 2019 | Helium Listed as a Critical Mineral, by Kruger, N.W. |
| January 2019 | Rare Earth Study, by Murphy, E.C. |
| January 2017 | Rare Earths in Coal, by Kruger, N.W. |
| January 2015 | A "Rare" Opportunity, by Kruger, N.W. |