Fluorite

The Rock Canyon Creek (Deep Purple) fluorite occurrence is located on Rock Canyon Creek, approximately 5 kilometres east- south east of its junction with the White River.

The area is underlain by a Cambro-Ordovician to Middle Devonian carbonate-dominated sequence. A west- dipping thrust fault places Cambrian and Ordovician strata over younger rocks. An overturned to upright homoclinal sequence, younging to the east, comprises coral-rich limestones of the Middle Ordovician-Silurian Beaverfoot Formation, unconformably overlain by dolomites, mudstone and solution breccias of the "basal Devonian unit", which are themselves conformably overlain by limestone of the Upper Devonian Fairholme Group.

Fluorspar and rare-earth mineralization is stratabound, hosted mainly by the "basal Devonian unit", and occurs in a northwest trend over 3.5 kilometres. The main type of fluorite mineralization identified consists of disseminations and veinlets of dark purple fluorite in a dolomite matrix. Associated minerals and elements include bastnaesite, pyrite, gorceixite, calcite, limonite, illite, barite, parisite, apatite, niobium, strontium and yttrium. Fluorite content generally varies from 2 per cent to greater than 10 per cent of the rock. Other types of occurring fluorite include: 1) higher grade, massive, fine-grained purple and white fluorite; 2) disseminated purple fluorite in white calcite, locally interbedded with dolomite and forming the matrix of solution breccias; and 3) massive purple fluorite in the matrix of an intraformational conglomerate.

A carbonatite-related origin is suggested for the fluorite and rare-earth mineralization, resulting from metasomatically altered (fenitized) Devonian carbonate rocks, possibly related to a deep-seated alkaline intrusion (Fieldwork 1988).

In 1977, five grab samples yielded up to 32 per cent fluorine and 7.7 per cent barium with lesser amounts of strontium and lead (Property File - C. Graf [1977-11-01]: Graf Lead-Zinc Reconnaissance - Southern Rocky Mountain - Volume I).

In 1986, a sample of brown-altered carbonate with fluorite (R85DP-1A) assayed 1.0 per cent cerium, 0.98 per cent lanthanum, 0.3 per cent neodymium, 0.058 per cent thorium and 0.03 per cent samarium. Approximately 700 metres to the east-southeast, a sample of altered carbonate with fluorite (R85DP-3) assayed 0.075 per cent thorium and a massive dark purple fluorite sample from a vein (R85DP-6) assayed 201 grams per tonne silver and 0.8 gram per tonne gold. Subsequent electron microprobe study identified a new silver telluride. (Assessment Report 14677).

In 1977, Riocanex completed a regional program of geologic mapping, silt sampling and prospecting on the area as the Deep Purple and Candy claims.