Skiluc: There are 4 great U.S. Carbonatites that I am aware of- Iron Hill, Bear Lodge, Mountain Pass & Elk Creek. The Elk Creek carbonatite, measuring ~7 square kilometers in southeastern Nebraska, is acknowledged by the USGS as 'potentially the largest global resources of niobium and rare-earth elements' and was successfully targeted in the past by Molycorp in the 70s and 80s. (A lot has gone on in 50 years.) Taken from this 2010 article- Quantum Rare Earth Developments Distinguished in BNN Interview and Mining Journal as Ideal Vehicle for Exposure to Niobium and REE https://www.prweb.com/releases/2010/05/prweb3975874.htm
Within the massive carbonatite there are several recorded occurrences of rare earth elements. Molycorp did not put in enough drill holes to calculate a resource for REEs however their geologists used terms to describe the situation unfolding in terms of 'tens of millions and megatonnes'. Drill hole intercepts (non NI 43-101) included 608ft of 1.18% lanthanides, 630 ft of 1.3%, 110ft of 2.09%, 460ft of 2.19%, 60ft of 3.89% -- Mining MarketWatch Journal notes these figures are massive and very good grades.
(****TO DATE THE ELK CREEK DEPOSIT HAS NOT BEEN FULLY EXPLORED. IT REMAINS OPEN AT DEPTH & IN TWO DIRECTIONS. SEE SUPPORTING DOCUMENTS BELOW:)
The Elk Creek deposit is a REE- and niobium-rich carbonatite that lies about 200 meters (m) below the surface; it was discovered in 1970 by a regional airborne geophysical survey (Long and others, 2010). Core drilling into the Elk Creek carbonatite during the 1970s, 1980s, and more recently in the 2010s has identified many intervals containing from 1 to more than 3 percent total REO. Recent (2019) developers of the Elk Creek property (NioCorp Developments, Ltd.) have emphasized the carbonatite’s potential resources of niobium, scandium, and titanium.
Magmatic REE The Elk Creek Project in Nebraska is being developed to mine the Elk Creek carbonatite. If developed, it will be the only niobium mine and primary niobium processing facility in the United States and will also produce scandium and titanium (U.S. Geological Survey, 2020). The Elk Creek carbonatite is a lower Paleozoic intrusive complex buried beneath 200 meters of sedimentary rocks. Niobium occurs as the mineral pyrochlore. A high-resolution airborne gravity gradient and magnetic survey flown over the carbonatite in 2012, combined with borehole and physical property data, provided an interpretation of the geophysical signature of the buried deposit and identified anomalies that could represent more mineralized rock at depth (Drenth, 2014). Niobium and tantalum also occur in a variety of peralkaline and related rocks, mainly in the western United States
(USGS & other articles indicate the resource could be much larger!) "Geophysical anomalies indicate that a significant volume of dense and strongly magnetized rocks must exist at a depth below the deepest boreholes. These rocks likely represent more MB and thus niobium mineralization, or could reflect another unknown lithology that is also dense and strongly magnetized."
("Hence more drilling"... to prove out more reserves once mine is sunk. This system could be connected to a larger or undrilled resource/s as depicted in the scans??? Just my opinion on the information presented that Niocorp could potentially double the size of the resource in time??)
All/Sharing Jims Response 5/27/22: a) Where would Niocorp’s Elk Creek mine stand/rank in relation to the other World Resources?
It is a bit tricky to compare rare earth projects on an apples-to-apples basis, which is why we chose to limit the comparison of our Elk Creek resource to other REE projects in the U.S. There are several reasons why.
For one, there are several different legal systems that determine how a project can measure and disclose aspects of its mineral resource and/or reserve. For public companies that are SEC-reporting entities (such as NioCorp), the SK1300 standard must be followed. For public companies regulated by Canadian authorities (also such as NioCorp), there is the National Instrument 43-101 disclosure standard. In Australia, there is the JORC standard. Each of these systems differ in what they allow, or don't allow, in terms of public disclosure of mineral resources and reserves. This can lead to 'apples-to-oranges' comparisons among projects.
Another challenge in making such comparisons is the mineralization of an REE project. Some projects can show a high ore grade of rare earths, but the mineralization of the ore is something that is very difficult to process. For example, rare earth projects based on silicate-based minerals -- such as eudialyte -- are extraordinarily difficult to economically process in order to pull the REEs out and separate them. Others can contain relatively high levels of other impurities, such as naturally occurring radioactive elements, that can increase the cost of processing. A high ore grade doesn't mean a lot if the REE mineralization isn't amenable to processing that is technically or economically infeasible. This is why only a small handful of the more than 200 REE-containing minerals have ever been successfully processed economically at commercial scale.(The two primary REE-containing minerals in the Elk Creek Project, bastnasite and monazite, are among those that have been successfully processed for decades).
Rare earth resources also differ in terms of the relative distribution of individual REEs in the host mineral. Some may have a relatively high ore grade but also have high percentages of less valuable REEs, such as cerium or lanthanum or yttrium. Others have lower ore grades but their REE mineralization is skewed more favorably to higher-value REEs, such as the magnetics neodymium, praseodymium, dysprosium, and terbium which are used in NdFeB magnets. There are several other REEs that are also magnetic, such as samarium, but those are of lower value.
Another way that REE projects are compared to one another is through a so-called “basket price.” This is a particularly misleading way of valuing a rare earth play, in my opinion, because a project’s ‘basket price’ assigns a dollar value to the individual REEs in the ore, multiplying total tonnes of each REE by current market price for that REE, and combines them all together. This assumes that a project will produce each and every one of the REEs in the ‘basket’ (which is almost never the case). It also ignores the enormous CAPEX and OPEX required to produce 14 or so individual REEs.
There are yet other factors that help determine the viability of a potential rare earth project.
~Some projects are aimed at only producing rare earths. That means that they are relatively riskier investments than projects that are designed to produce multiple products in addition to rare earths.
~Some projects that are relatively large in size, have high ore grades, and are comprised of processable minerals -- but they are located in places that make mining and processing difficult or very expensive. I can think of a few projects that are touted as attractive deposits but are located near or above the Arctic Circle, which generally makes mining more costly. Others are located in places where there local residents, such as First Nations communities in Canada or anywhere in Greenland, can readily block a project from moving to commercial operation. Still others are in countries where local governments are less stable than in the U.S., or are simply prone to corruption, which exposes the project to high country risk.
~Many REE projects are proposed by teams that have no experience in commercially processing REEs. They tend to gloss over that fact. Knowing what I know about the challenges of producing separated, high-purity REEs, this is one of the most important factors I consider when I look at REE projects. But that is just my opinion.
A more useful comparison strategy for investors is to look at rare earth projects through multiple lenses, such as those I describe above. It is not easy to do this if one doesn’t have a pretty deep understanding of the REE industry and the challenges of successfully making these strategic metals.
Having said all of that, it’s clear that our Elk Creek carbonatite is very large and similar in total contained rare earths to some of the largest known rare earth resources in the world, including the Araxa carbonatite in Brazil and the St. Honore carbonatite in Quebec. (NIOBEC)
I hope this information helps, and that you have a great Memorial Day weekend. Jim Sims
IMHO: I think the Elk Creek Resource is a heck of a lot larger than the most recent June 2022 F.S. & supporting drilling, NI-43-101 & market compliant resource estimates acknowledge. Scott did state to BM & others the team wants to get drills down shaft ASAP (As finance allows!) "YES" for me too! Waiting for Demo Phase 1 REE "Extraction- Proven!" in my Front Row Seats with many into 2026 now I think for production!
