Summary:
The Project is hosted within the Elk Creek Carbonatite. By definition a carbonatite is an igneous rock body with greater than 50% modal carbonate minerals, mainly in the form of calcite, dolomite, ankerite, or sodium- and potassium-bearing carbonates. Carbonatites commonly occur as intrusive bodies, such as isolated sills, dikes, or plugs, although rarely occur as extrusive rocks. Many carbonatites are associated with alkali silicate rocks (for example, syenite, nepheline syenite, ijolite, urtite, pyroxenite, etc.). Carbonatites are usually surrounded by an aureole of metasomatically altered rocks called fenites. Carbonatite-associated deposits can be classified as magmatic or metasomatic types (Richardson and Birkett, 1996).
Geology
The property includes the carbonatite that has intruded older Precambrian granitic and low- to medium-grade metamorphic basement rocks. The carbonatite and Precambrian rocks are unconformably overlain by approximately 200 m of Paleozoic marine sedimentary rocks of Pennsylvanian age (ca. 299 to 318 Ma).
As a result of this thick cover, there is no surface outcrop within the Project area of the carbonatite, which was identified and targeted through magnetic surveys and confirmed through subsequent drilling. The available magnetic data indicates dominant northeast, west-northwest striking lineaments and secondary northwest and north-oriented features that mimic the position of regional faults parallel and/or perpendicular to the Nemaha Uplift.
The Elk Creek Carbonatite is an elliptical magmatic body with a northwest-trending long axis perpendicular to the strike of the 1.1 Ga Midcontinent Rift System, near the northern part of the Nemaha uplift (Burchett, 1982; Carlson, 1992). The definitive confirmation of carbonatite was completed using Rare Earth Element (REE), P2O5 and Sr87/Sr86 isotope analysis (Brookins et al., 1975). The carbonatite has also been compared to the Iron Hill carbonatite stock in Gunnison County, Colorado, based on similar mineralogy (Xu, 1996).
The carbonatite consists predominantly of dolomite, calcite and ankerite, with lesser chlorite, barite, phlogopite, pyrochlore, serpentine, fluorite, sulphides and quartz (Xu, 1996).
Mineralisation
The property hosts niobium, titanium, and scandium mineralization as well as REE and barium mineralization that occur within the Elk Creek Carbonatite.
The current known extents of the high grade niobium, titanium, and scandium are approximately 750 m along strike, 400 m wide, and 800 m in dip extent below the unconformity.
Niobium and Titanium Mineralization
The deposit contains significant concentrations of niobium. Based on the metallurgical test work completed to date at a number of laboratories using QEMSCAN® analysis, the niobium mineralization is known to be fine-grained, and that 77% of the niobium occurs in the mineral pyrochlore, while the balance occurs in an iron-titanium-niobium oxide mineral of varying composition. Within the mineralized Carbonatite, there are 14,284 samples of Nb2O5, the maximum Nb2O5 grade is 4.472%, and the mean Nb2O5 grade is 0.518%.
Scandium Mineralization
Within the Elk Creek Carbonatite, a host of other elements exist with varying degrees of concentration. The Company has completed both whole rock analysis and multi-element analysis
on all samples for the 2014 program, plus re-sampling of selected historical core and/or pulps between 2011 and 2014.
As the metallurgical test work advanced during 2014 and 2015, the ability to obtain a titanium dioxide (TiO2) and scandium (Sc) product became apparent. TiO2 is typically found to be related to the niobium grades with a range of 3:1 to 4:1 found within the core of the deposit. The scandium mineralization does not directly correlate to niobium mineralization but does show a grade increase with increasing niobium at low grades and high grade Scandium (>75 ppm) is also associated with higher grade concentrated distributions of CaO, Mgo, Th, U and Pb and As.
Rare Earth Element Mineralization
Within the Elk Creek Carbonatite complex, there are several occurrences of REE mineralization, including the Project. REE mineralization within the Carbonatite occurs within the following minerals:
• Bastnäsite ([Ce,La,Y]CO3F);
• Parisite (Ca[Ce,La]2[CO3]3F2);
• Synchysite (Ca(Ce,La)(CO3)2 F);
• Monazite ([Ce,La]PO4).