The Spokane occurrence consists of a zone of copper mineralization in volcanic rocks, in rugged terrain 5.5 kilometres south of the southern end of Tatlayoko Lake. It is located in an area with a long history of exploration primarily devoted to gold-silver-antimony-bearing quartz veins, which outcrop in sedimentary rocks about 500 metres to the southwest, and which are covered by the Morris occurrence (092N 002).
The Spokane occurrence is underalin by unmetamorphosed immature clastic rocks and some interbedded volcanics of the Lower Cretaceous Cloud Drifter Formation just north of a south-dipping thrust sheet comprising Late Triassic to Cretaceous metamorphic rocks of the Eastern Waddington thrust belt imbricate zone. These clastic rocks are intruded by dikes and by hornblende plagioclase porphyry. The Morris prospect is located about 6 kilometres north of a large granodioritic intrusion of the Bendor suite.
The occurrence is hosted in interbedded andesitic and basaltic volcanics, which strike 340 degrees and dip 70 degrees northeast (Assessment Reports 1663, 10520). At least one porphyritic rhyolitic dike, striking 280 degrees and dipping 75 degrees south, intrudes the volcanics; it pre-dates mineralization.
Most of the mineralization is confined to one 60-metre-thick unit of andesite, particularly along its northeastern margin adjacent to a unit of purple-brown basalt; the basalt is virtually unmineralized. This mineralization extends, somewhat erratically, for over 600 metres, with a surface width varying from 1 and 15 metres. Within this strike length is a central zone about 210 metres long and averaging 8 metres in width, where mineralization is strongest.
The mineralization consists of chalcopyrite and bornite, with rare chalcocite. These minerals are disseminated in the andesite, and locally occur as fracture-fillings, associated with calcite and epidote (Assessment Reports 1663, 10520). Malachite is abundant. Various assay results are given in the reports cited. While results from individual samples may be high, a more representative average of 11 chip samples taken over the strike length of the zone, with an average width of 6 metres, was 1.04 per cent copper (Assessment Report 1663). Another suite of samples yielded 1.25 per cent copper and 6 grams per tonne silver (Assessment Report 1663). Five samples averaged 1 gram per tonne gold (Assessment Report 10520).
It was estimated that the occurrence contains 335,000 tonnes grading 1.5 per cent copper (undiluted), based on a strike length of 210 metres, a width of 8 metres, and a vertical extent of 6 metres (Assessment Report 1663).
WORK HISTORY
The property covers a gold showing on the Tyee claim (Lot 700) (92 N/8, Au I), and a copper showing located 610 metres northeast of the gold showing at the southeast corner of the Spokane claim (Lot 702). Showings of copper carbonate and copper staining were discovered and staked in 1907 by I.T. Morris and A.H. Sheppard. The property originally comprised 11 or 12 claims divided into two adjoining groups identified as the "Gold Camp" and "Copper camp". The owners incorporated The Tatlayoco Lake Copper Company Limited in November 1909 and The Tatlayoco Lake Gold Mines, Limited in February 1910. Crown-grants were issued in 1918 to the latter company on 6 of the most important claims, forming a contiguous block and including the Tatlico, Tyee, Isaac T, Spokane, Copper Dyke Extension, and Copper Dyke (Lots 699-704 respectively).
Exploration work to 1910 on the Copper Camp claims included two adits driven 91.4 and 55metres respectively. The upper adit was driven on a basic dyke about 4 feet wide with a seam of calcite about half an inch wide on either side of it. No indication of mineralization was exposed except a little copper stain. The lower adit, driven as a crosscut, failed to locate the vein. No further activity was reported in the Copper Camp claims.
In January 1949 Rico Copper Mines, Limited acquired the 6 Crown-grants from Panameric Mines & Resources, Limited in exchange for an allotment of Rico shares, however no work was reported and Rico was dissolved in November 1965. A new company Rico Copper (1966) Limited was incorporated in January. Work on the Crown-grants and adjacent Tat 1-9 claims in 1968 included detailed geological mapping, and sampling by R.W. Phendler; a 457 metre strike length of copper showing averaged 1.04 per cent copper across an average width of 6 metres; the middle 213 metres averaged 1.63 per cent copper across average 8.2 metres width. Inferred reserves are estimated as 335,664 tonnes at 1.2 to 1.5 per cent copper (BC Inventory, 92 N-1).
Stryker Resources Ltd. in May 1980 acquired an option to puchase the Crown-grants from Rico Copper. The Tatlico 1 and 2 claims (18 units) and JB 1 & 2 (2 units) were staked over the Crown-grants. Sampling on the copper showing by C.W. Ball indicated lower values than those obtained by Phendler.
In 2003, C.J. Greig and B.J. Kreft, optioned the property to Firestone Ventures. Firestone worked on the property during 2004 focusing on the high-grade veins (Assessment Report 27531). The program consisted of detailed geological mapping, prospecting, and rock, soil and silt geochemical sampling across two areas, the "Morris Mine" area and the "Copper Zone" area. The Copper Zone was found to cover a 500 by 100 metre area, larger than reported in earlier reports. A talus float train identified in 2004 of quartz-arsenopyrite plus/minus stibnite vein material extending onto the Copper Zone area indicates an uphill source to the southwest.
In 2008, the Morris Mine Property, optioned by Richfield Ventures Corp from C.J. Greig and B.J. Kreft, was mapped and soil sampled (Assessment Report 30985). As well the access road to the property was rendered passable, the number 1 vein was resampled, the Copper Zone tested, and historic drill results replotted and analyzed. Some 582 soil samples were collected on a 1600 metre by 1800 metre grid with lines spaced at 100 metre and samples every 50 metres. Generally elevated response in arsenic, antimony, manganese and iron is seen on the south part of the grid where the arsenopyrite-stibnite-gold-silver veins occur. No significant response was seen elsewhere on the grid.
