This region of southeastern British Columbia is underlain by miogeosynclinal strata comprising marine clastics and carbonates of Devonian to Jurassic age and non-marine fluvio-deltaic clastics of Late Jurassic and Early Cretaceous age. The strata are exposed in a broad north trending doubly plunging synclinorium known as the Fernie Basin. These units are disrupted by secondary folding accompanied by thrust and normal faulting. Such structures trend north to northwest.

The area in the vicinity of Dally Hill at the south end of the Fernie Basin is underlain by quartzose siltstones and fine-grained sandstones of the Permian Ranger Canyon Formation (Ishbel Group), overlain by siltstones and calcareous siltstones of the Triassic Sulphur Mountain Formation (Spray River Group), followed by shales and siltstones of the Jurassic Fernie Group. The strata dip gently southeast into Dally Hill.

In the Cabin East occurrence area, a poorly exposed horizon of pelletal to massive phosphate (at the base of the Fernie Group) has been traced southwestward for 500 metres along the northwest flank of Dally Hill. Bedding at one point strikes 058 degrees and dips 20 to 75 degrees southeast. The horizon contains 1.25 metres of dense phosphate with limonite blebs, overlain by 0.25 metre of thin-bedded shale, which is in turn overlain by 1.5 metres of pelletal phosphate. The entire sequence is capped by 2.5 metres of chocolate-coloured shale or by brown and black shales and a yellow bentonite bed. A grab sample (DLY89-13) of black massive phosphate assayed 30.85 per cent P2O5 and 0.93 per cent yttrium (Assessment Report 19948).

WORK HISTORY

Phosphate strata in the Cabin Creek area were most recently (late 1970's and early 1980's) explored by Imperial Oil Limited (Assessment Report 7617) and First Nuclear Corporation Limited (Assessment Report 10135). In 1981, First Nuclear commenced a program of airborne and car-borne radiometrics followed by field prospecting and caterpillar trenching in order to assess the surface exposure of the favourable sediments exposed along the erosional edge of the Fernie basin some 72 kilometres in length. A total of 18 sections were exposed through the basal portion of the Fernie Formation. First Nuclear Corporation found a phosphorite section on what are now the Cabin East claims that contained 29.73 per cent P2O5 across 1.9 metres and was traceable along strike for approximately 500 metres (Assessment Report 10135).

Formosa Resources Corporation began exploration for yttrium and phosphate in the area in the spring of 1989 and staked a number of claims, including the Cabin East claims, as part of the Columbia Project (Assessment Report 19948). In all, 5 rock samples were taken from outcrop, from 2 hand trenches and 3 back-hoe trenches. Samples were analyzed for P2O5 (by gravimetric assay), yttrium (by XRF) and for 34 trace elements, including some of the rare earths. Some 200 hectares of geological mapping was completed at 1:12,500 scale.

Refer to Cabin G (082GSE068) and Storm Creek (082GSE061) for related details on the Cabin Creek claims of Formosa Resources.