The Crow sandston/frac sand occurrence is located Beavercrow Mountain, approximately 2 kilometres south of the British Columbia and Yukon border.
The area is underlain by north-northeast trending clastic and carbonate sedimentary rocks of Mississippian to Cretaceous age. The oldest rocks exposed in the central part of the area are quartz rich sandstones of the Mississippian Mattson Formation. These rocks are exposed in the core of several northeast oriented anticlines, and are flanked by chert, siliceous argillite and siliciclastic rocks of the Permian Fantasque Formation and coarse clastic sedimentary rocks of the Carboniferous and Permian Kindle Formation.
The Crow property was staked to cover a sedimentary succession of quartz-rich sandstone (Mississippian Mattson Formation). The quartz-rich sandstone is regarded to be a potential economic source of high-value frac sand, a commodity that is used in the extraction of hydrocarbons, and in particular shale-hosted natural gas.
Locally, quartz sandstone (Mattson Formation) occurs as a thin to thick bedded unit that is locally cross-bedded and forms a resistant cap to a series of mesa features. The quartz sandstone strikes northeast and dips gently to the southeast and may be in excess of 100 metres thick. The sandstone is fine-grained to very fine-grained and is off-white to buff weathering. On fresh surface it is off-white to pale lavender, but commonly is pale orange where stained by iron oxide. The quartz sandstone occasionally reacts weakly to dilute HCl indicating the presence of calcite as matrix and/or cement.
Six representative samples collected from the property in 2010 and whole rock analysis (by XRF) and trace element analysis was conducted on these samples. The resulting analysis showed an average silica content of 91.6 per cent SiO2, an alumina content of 1.1 per cent Al2O3 and an iron content of 0.72 per cent Fe2O3 (Table 3 and Appendix A, Assessment Report 32344B). The resulting trace element analysis identified elevated levels of zirconium with an average of 317.2 parts per million.
A typical thin-section description (sample CR10-BL02) follows: Very fine-grained quartz sandstone with maximum grain size about 0.2 millimetre, with angular to subangular clasts. Composite/welded grains common, very little cement. About 5 per cent opaque minerals. About 1 per cent lithic clasts about 0.2 millimetre in diameter, possibly devitrified volcanic glass. About 1 per cent unidentified isotropic green mineral.
In 2009 and 2010, Stikine Energy conducted programs of mapping and geochemical sampling. Whole rock analysis of two samples, thought to be representative of the area, returned a silica content of 97.08 per cent and 98.09 per cent, an alumina content of 1.21 and 0.31 per cent and an iron oxide content of 0.34 and 0.33 per cent (Assessment Report 31618).
In 2010, the work program consisted of bedrock mapping, geochemical sampling and laboratory analytical work (Assessment Report 32344B). Field observations and results from analysis of selected samples from the Crow property indicate that it has potential to host bedrock material suitable for processing into frac sand.
