The Low Grade occurrence is located on a southwest-facing slope, southwest of Needlepoint Mountain and approximately 5 kilometres south of Simmons Lake.
Regionally, the area is underlain by granitic intrusive rocks along the eastern margin of the Lower Cretaceous Cassiar Batholith, which have intruded undivided sedimentary rocks of the Neoproterozoic Ingenika Group; calcareous sedimentary rocks of the Lower Cambrian Rosella Formation (Atan Group); quartz arenite sedimentary rocks of the Lower Cambrian Boya Formation (Atan Group) and limestone, slate, siltstone and argillite of the Ordovician to Silurian Road River Group.
The occurrence is underlain by impure limestone of the Lower Cambrian Rosella Formation (Atan Group) that has been altered to black magnetite-rich skarn in a zone adjacent to granitic rocks of the Lower Cretaceous Cassiar Batholith. The mineralized zone is exposed for approximately 100 metres along strike to the north with a dip of 20 degrees east and an average width of 12 metres.
The skarn is partly banded, with massive magnetite, chlorite, garnet, diopside and irregular patches of quartz and fluorite. Danalite, a beryllium-iron silicate of the helvite group, occurs as small grains, clusters and stringers up to 2 centimetres long. It is accompanied by a few small grains of native bismuth. Overall beryllium content of the occurrence is considerably less than 1 per cent (McDougall, 1954). Up to 0.038 per cent tin is reported from spectroscopic analysis. Mineralization also includes sphalerite and pyrrhotite. Powellite, a tungsten-bearing mineral, is also reported in the occurrence area associated with molybdenite.
In 1980, rock samples from the occurrence area yielded up to 0.36 per cent copper, 15 per cent zinc and 8.6 grams per tonne silver (Assessment Report 9344). The following year, rock samples yielded up to 40.1 per cent zinc and 0.32 per cent tungsten (Assessment Report 10105).
In 1986, the highest results from eight 1.5-metre channel samples of massive magnetite were 0.29 per cent bismuth, 0.08 per cent zinc, 2.7 grams per tonne silver and 708 parts per million tungsten (Assessment Report 15591).
Work History
In 1954, J.J. McDougall of the St. Eugene Mining Corporation discovered the occurrence and staked the Low Grade Claims.
During the latter part of the 1960s, Scurry Rainbow undertook an option on the property; however, other than a brief property examination, nothing was done on the property and the claims were allowed to lapse. Upon restaking the area in 1969, B. Wiseman of Cassiar began a small high-grade mining operation. In total, 5.7 tonnes of ore were flown down to the Stewart-Cassiar Highway by helicopter then trucked to Trail for smelting.
In the summer of 1979, following the release of stream sediment data by the Geological Survey of Canada (Open File 562), Canadian Occidental Petroleum Ltd. staked 54 units covering the area now occupied by the Filthy-Rich claim group. Upon staking, a limited program of prospecting, geological mapping and geochemistry was undertaken. During 1980, a more detailed exploration program was carried out by Canadian Occidental Petroleum Ltd. This work consisted of geological mapping, soil sampling, rock sampling plus stream sediment and heavy mineral sampling. The results of this work revealed a number of geochemical anomalies in addition to the discovery of several small showings. Encouraged by the results obtained in 1980, Canadian Occidental Petroleum Ltd. returned to the property in 1981. A more detailed program was conducted over three areas of interest: 1) the Rich showing, 2) a soil anomaly located in the southwest corner of the Filthy 1 claim and 3) a soil anomaly located immediately west of the Filthy 1 claim. The results of the 1981 program were inconclusive, consequently a decision was made to not carry out any further work on the property.
In 1985, Colony Pacific visited the Rich showing collecting two samples. Later in 1986, a decision was made to option the property. In 1986, Colony Pacific Explorations Ltd. conducted an exploration program consisting of line cutting, grid establishment, geological mapping and soil sampling on the Rich 3 claim. This was followed by the drilling of two diamond drill holes (AX size) totalling 47.7 metres in length. During the course of this work a total of 55 soil samples and 17 rock samples were submitted for analyses.
In 1996, Cartaway Resources Corp. completed a 3678.0 line-kilometre airborne magnetic survey on the area as the Hot Tip property.
In 2014, Angel Jade Mines Ltd. completed a short survey over their Cottonwood property, which covers the Rich and Low Grade (MINFILE 104P 026) showings. The survey was conducted to determine if the previous mention of elevated beryllium values are of economic interest by sampling the old showings, assessing the state of access to the old workings area and whether the higher (subalpine to alpine) areas could be reached without the use of helicopter support, considering if stream sediments collected from the drainages from the old workings areas contain elevated beryllium values, and if remote sensing, particularly the mapping of iron oxide alteration, would assist in locating concentrations of magnetite, the historical host of the beryllium mineralization. A remote sensing study of the project area was performed utilizing both Landsat 7 and ASTER imagery. The purpose of the study was to evaluate the potential of the multispectral imagery to identify areas of enhanced iron oxidation and/or clay alteration. A short program consisted of sampling and a prospecting survey. The sampling and traverses were confined to collecting stream sediment samples in the drainages transecting the old workings area as access by foot to the target areas at the higher elevations was not practical without either helicopter support or having the old drill access road brushed out for ATV access. A total of four stream sediment samples were collected from the creeks draining the old workings area.
