RELEASED ON BEHALF OF: ROCK RESOURCES INC V-RKR
September 9, 1999
ROCK RESOURCES POISED TO DRILL SUBSTANTIAL PROSPECTIVECOPPER-GOLD TARGET IN CHILEAN ANDES
Mt Tacho Shows All Characteristics Of Classic Porphyry-Style Deposit:C$15m Compensation Claim Being Pursued Against BC Government
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Rock Resources Inc, a Vancouver junior exploration company, has two distinct objectives:
To undertake more extensive diamond drilling of the Mt Tacho prospect on its Coiron property situated some 2,700m above sea level in the Chilean Andes. Rock's consultant geologist, Mr John Ostler, believes that the geological/geophysical evidence assembled to date indicates that a major new copper-gold deposit of more than 1 billion tonnes could be discovered.
To expedite legal action claiming over C$15 million compensation from the British Columbia Government for some of the company's mineral claims which were appropriated in 1995 for inclusion in one of 80 new provincial parks. The BC Government has formally promised that reasonable compensation will be forthcoming. A precedent was set when the government paid C$166 million to Royal Oak Mines, the gold mining company that had its Windy Craggy project appropriated for the Tatshenshini-Alsek wilderness park. Mr Tom Kennedy, Rock's president and a solicitor-barrister who is a former prosecutor for Canada's Federal Department of Justice, says the company is resorting to court action to speed up the compensation process.
LOCATED IN WELL MINERALISED BELT
Coiron is located approximately 170km north of Santiago at an elevation of 2,000m-3,000m. It lies on a NE trending linear geological feature which hosts two major copper porphyry deposits, Los Pelambres (Anaconda Chile) and El Pachon (Cambior Inc). These lie 32km to the north-east of Mt Tacho and are of similar geological age to it. Eight major mining companies have signed confidentiality agreements to view Coiron, and Rio Tinto, Billiton and Codelco have acquired ground immediately south of it.
Geologically, the property is characterised by a sequence of mainly andesitic volcanics intruded in the north part by an early-Eocene age granodiorite. Within the andesite sequence is a quartz-tourmaline-pyrite rich breccia which, together with its alteration halo, covers an area of more than 2km2. The breccia passes downwards into a monzonitic stock, the Igor intrusive, which has undergone pervasive potassic alteration with the associated growth of magnetite.
The breccia is also flanked by a zone of sericitic alteration within which are copper-gold bearing veins, virtually the only surface expression of mineralisation at Mt Tacho. They are steeply dipping, NE-trending structures up to 10m wide which can be over 700m long. They have been mined locally by artisanal workers down to the limit of weathering, indicating the presence of economic mineralisation.
The alteration haloes associated with the breccia and Igor intrusive constitute the Mt Tacho hydrothermal system. Mr Ostler believes this displays all the geological/geophysical features of a porphyry system that is large enough "to host a significant porphyry copper-gold deposit similar to Los Pelambres" (930 million tonnes mineable at 0.75p.c. copper).
Induced polarisation and magnetic surveys were carried out at the end of 1998, the results of which were incorporated into a comprehensive geological review and report on the Mt Tacho prospect prepared by Mr Ostler. This revealed that the Mt Tacho hydrothermal system closely matches the "Sillitoe model" for gold-rich porphyry copper deposits. This model was developed in 1993 by Professor Richard Sillitoe, an expert in Latin American mineral deposits, following a study of 29 gold-rich porphyry copper deposits in which he listed the main characteristics common to each. His itemised list of nine determining attributes became accepted as the type-description for such deposits
Ostler's geological review showed that the Mt Tacho hydrothermal system conforms to all five of the geological attributes that are most required by the Sillitoe model (coeval volcanic rocks present, 2 phases of alteration, magnetite-haematite deposition, and stockwork vein development). The system also falls within the "significant" category for the other four attributes that vary more widely among the 29 deposits studied (age, geological setting, geological classification and detailed petrochemistry of host intrusion).
This classical geological "signature" and the strong geophysical footprint (approx 1,100m by 1,000m) are consistent with, but not exclusive to, gold-rich copper porphyry deposits.
However, Mt Tacho also exhibits a concentric pattern of structures, alteration and tourmaline deposition within the breccia which suggests it is the surface expression of single large system of fluid migration originating in a magma body intruded at depth. This combination clearly makes Mt Tacho a high priority drill target.
LIMITED DRILLING TO DATE
The very limited drilling so far completed (7 holes) pre-dated the geophysical surveys and was carried out with the objective of investigating the flanking vein system and breccia at depth and in sufficient detail to understand the local geology. Mineralised veins were intersected in 3 holes drilled east of the main hydrothermal system. Sub-economic copper-gold values were returned from beneath the zone of surface weathering (it is suggested that better grades are confined to near surface supergene zone). Three other holes were centred on the tourmaline breccia near its SW margin. Although no significant ore intersections were encountered, the subsequent IP survey suggested the holes had penetrated the "barren" core of the hydrothermal system. Rock believes this interpretation more than justifies another round of drilling which will focus on targets identified by Mr Ostler. Spending C$1m on this programme "should give us a good taste of what's there", says Tom Kennedy.
Ownership of the 33km2 Coiron property is vested in De La Chevre Noire Ltd (DLCN). To date, Rock has spent approximately C$3.5 million on the property, of which about 40p.c. is direct acquisition costs. This expenditure has earned Rock a 40p.c. interest in DLCN under an earn-in agreement, the terms of which were recently re-negotiated to give it the right to acquire 100p.c. of DLCN via a combination of exploration spending and the issue of Rock shares. Once the 70p.c. level has been reached, however, the remaining 30p.c. stake will be extinguished in favour of a 3p.c. net smelter royalty to the original shareholder of DLCN which may be bought down to 1p.c. for US$2 million. The new terms and the extension of the next phase of the earn-in (to 50p.c.) to end-2000 are more favourable to Rock.
Rock Resources has 30.33 million shares on issue which, at the current share price of 17 cents, gives it a market capitalisation of around C$5 million. Directors and associates control about 40p.c. of the shares.
Rock's president, Mr Tom Kennedy, has ten years public company management experience, including several years in the mineral resources sector with Rock.
He is responsible for corporate development and furtherance of the company's compensation claim in the Supreme Court of British Columbia. Fellow directors include Chris Sampson, a graduate geologist from the Royal School of Mines, whose previous experience includes 15 years as exploration geologist/manager with Rio Tinto and Brinex Ltd, and geologist John Kowalchuk. He is an accomplished exploration manager and "mine finder" who has served with a range of mining companies, including Placer Dome, and was instrumental in the discovery of the Kerr porphyry copper-gold deposit and the Howard's Pass and Driftpile Creek zinc-lead SEDEX deposits. |
