Other Projects

Rimfire Portfolio - RDN, BC

Eskay Creek-style gold and silver-rich stratiform sulphides

Barrick's Eskay Creek mine is Canada's highest-grade gold mine and the world's fifth largest silver producer. Production and reserves total 4.0 million oz gold and 153 million oz silver at a grade of 48.4 g/t (1.4 oz/ton) gold and 2221 g/t (63 oz/ton) silver. Most of the ore lies within stratiform lenses of precious metal-rich sulphides and sulphosalts overlying rhyolite domes in a volcanogenic massive sulphide (VMS) setting. Rimfire has no direct or indirect interest in the Eskay Creek Mine.


Northgate earning 51% interest by funding $5 million in exploration

Rimfire owns 100% of the 149 sq. km RDN property, subject to a 1.33% NSR. Northgate Minerals Corporation is in the first year of an agreement allowing Northgate to earn a 51% interest in the RDN by making property exploration expenditures totalling C$5 million by December 31, 2007 and cash payments totalling C$200,000 to Rimfire. After vesting its interest, Northgate can earn an additional 9% (for a total of 60%) by funding all expenditures through to the completion of a positive feasibility study. Rimfire remains project operator until Northgate has vested its 51% interest in the joint-venture.


Correlative to Eskay Creek

Regional (right) and property-scale (left) maps of the RDN Property. Barrick's Eskay Creek Mine road passes within 15 km of the RDN Property. 221 KB, approx. 42 seconds at 56.6Kbps

The RDN property covers a felsic centre which lies near the top of the Early to Middle Jurassic Hazelton Group. Variably altered dacitic to trachytic volcanics and subvolcanic intrusives, with lesser rhyolite, are overlain by carbonaceous, pyritic argillite and pillow basalt. This stratigraphy is correlative to that of the Eskay Creek deposit, which is hosted by a carbonaceous, pyritic, argillite horizon above a rhyolitic flow-dome complex and beneath pillow basalt.


High-grade "footwall" veins and clastic massive sulphides

Initial exploration (1989-92) of the RDN claims focused on gold-rich quartz sulphide veins, including drill intersections of 1.95 metres @ 101 g/tonne (2.95 oz/ton) gold and 0.85 metres @ 138 g/t (4.0 oz/ton) gold. These high-grade intersections are hosted by altered dacitic tuffs, the "footwall" in the Eskay Creek model. At Eskay Creek, high-grade footwall veins were the focus of exploration for fifty years prior to the discovery of the stratiform orebodies.

The Marcasite Gossan is an altered and stockwork-veined dacite, with textures indicative of emplacement and mineralization at shallow water depths on the seafloor. Float discovered in 1998 of clastic massive pyrite shows that this hydrothermal system vented to the sea floor and accumulated as stratiform sulphides. The Eskay Creek stratiform orebodies are at this same stratigraphic level in the Hazelton Group and were also emplaced at shallow depths.


Plans for 2006 include drilling and an airborne magnetics and electromagnetics geophysical survey of the Arctic Grid. A budget of $1 million dollars has been committed for this work.

The Arctic Grid was targeted for drilling due to the presence of Eskay Creek-equivalent stratigraphy exposed on surface. 2005 results have shown that rhyolite within this stratigraphy is very similar geochemically and in age (as defined by precision age dating) to rhyolites intimately associated with mineralization at Eskay Creek.

Two stratigraphic drill holes (RDN05-43, 45) were completed on the Arctic grid, approximately 1.5 kilometres apart. Both holes cored interbedded mafic volcaniclastic fragmentals and mudstones occurring above a thick package of sericite-altered rhyolite flows and black matrix breccia. This is a geologic environment conducive to the formation of massive sulphide deposits. Both drill holes exhibit elevated barium at the rhyolite-sediment contact; elevated silver and zinc in the volcaniclastic-sedimentary assemblage; and discontinuous but elevated arsenic within the rhyolite. The prospective rock assemblage extends for at least 5 km through the Arctic Grid area, where the surface geology is partially hidden by glacial overburden.