An Insight into the Nature of REE Mineralisation in the Eastern Part of the Ice River Complex, British Columbia

In a developing world, an increased interest has been placed by governments on identifying a domestic source of critical metals, including the rare earth elements (REE). From a geochemical standpoint, the REE include the lanthanide series (La-Lu) plus yttrium (Y). Light rare-earth elements (LREE) comprise lanthanum (La) to europium (Eu), which are enriched in alkaline igneous rocks and carbonatites. Carbonatites are notable to exploration companies for elevated LREE and other incompatible element concentrations. To form economic concentrations of REE in carbonatites, evolutionary processes are required to raise REE concentrations to economically viable levels. 

One example of a carbonatite associated REE exploration prospect is located on the eastern aspect of the Ice River Complex (IRC). The IRC is a late Devonian to early Carboniferous alkaline intrusion hosted in weakly metasomatised Cambro-Ordovician deepwater country rocks. The oldest parts of the intrusion comprise a feldspar-poor, jacupirangite to urtite series, which is crosscut by carbonatites and feldspathoid syenites, and in turn crosscut by lamprophyre dykes. 

As previous work on the Ice River carbonatites is limited, further analytical work is required to understand the source(s) of these rocks, their relationship to the other intrusive units, and the character and distribution of associated REE mineralisation. Herein the focus of this presentation will be the mineralogical, textural, and paragenetic characteristics of the eastern Ice River carbonatites, with special attention being paid to REE-bearing phases.