The claims are underlain by Lower Jurassic Hazelton Group volcanics of the Telkwa Formation, comprised of red, purple, green to grey andesitic to rhyolitic flows, tuffs, and breccia. South of Limonite Creek, a large Eocene Nanika Intrusive comprised of porphyritic granodiorite and quartz monzonite intrudes the volcanic rocks. A host of associated quartz veins containing disseminated pyrite crosscut the volcanics.
The age determination is of Eocene Nanika Intrusion which has a good lower intercept and a less well defined upper intercept of about 300 Ma indicating inherited zircons of this age. The authors suggest this is a post mineralization age.
Alteration zones at the Limonite Creek occurrence have been studied with modern instrumentation and 4 types (in addition to sericitic and propylitic) have been discerned:
1. Acid sulphate alteration is characterized by the presence of alunite and quartz, with or without pyrophyllite.
2. Advanced argillic alteration with quartz and pyrophyllite.
3. Aluminous alteration is characterized by andalusite, quartz and local lazulite.
4. Anhydrite-quartz is distal to most intensely altered rocks. These types of alteration are characteristic of high sulphidation systems.
The weathering of pyrite has occurred to a depth of at least 135 metres and goethite has been redistributed to make this iron deposit (EM Fieldwork 1997, pages 31-1-9).
On the north side of Limonite Creek, a large gossanous area hosts yellow and brown earthy limonite which occurs in platey layers from 2.5 to 7.6 centimetres in thickness, paralleling the surface of the hill which dips 30 degrees south. Thicknesses of 6.7 metres were encountered with an average thickness of 3.0 metres of clean limonite. In 1915, samples taken by the Mines Branch in Ottawa assayed 52.19 to 55.01 per cent iron, 0.83 to 1.99 per cent silica, 0.39 to 0.85 per cent manganese, 0.016 to 0.616 per cent phosphorous and 1.14 to 1.52 per cent sulphur. These results are the averages from 9 samples collected over 18.2 hectares (Minister of Mines Annual Report 1957, page 12).
Exploration in the Limonite Creek area was first recorded 1914, when the limonite deposits were explored by open cuts and trenches. In 1957, Shawano Iron Mines Limited drilled 27 holes on the limonite deposits, noting a thickness of up to 6.7 metres. Drill indicated reserves based on 27 drillholes are 3,175,200 tonnes grading 44 per cent iron (Minister of Mines Annual Report 1957, page 12).
In 1963, Noranda Explorations Limited drilled a hole (37.5 metres) north of the “upper gossan,” but failed to find the sulphide zone.
Pacific Petroleum Limited conducted geological, geochemical and geophysical surveys in 1969 and completed two diamond-drill holes during 1970. Both were drilled in propylitized dacite tuff and both encountered minor disseminated pyrite with sparse chalcopyrite and rare bornite.
In 1992, Cyprus Canada optioned the Bear claim and conducted pulse EM and geochemical surveys, geological mapping and 394.5 metres of diamond drilling in three holes. This work identified four narrow conductors with in zones of alteration and a 150 by 300 metres copper soil anomaly with ranges from 200 to 2456 parts per million copper (Property File Placer Dome Hanson, 1992).
