Eagle Gold-Silver Project. Northwestern British Columbia

Transcription

1 Eagle Gold-Silver Project Northwestern British Columbia

2 Eagle Gold-Silver Project Targeting an epithermal gold-silver system associated with a rhyolite dome intruding the ring-fault system of major Eocene caldera complex Outcropping quartz-chalcedony veins with up to 879 g/t Ag Bonanza grade float discovery in 1988 never followed up Eagle Project A. Location and Access The Eagle Project is located in northwestern British Columbia approximately 80 kilometres south of Whitehorse, Yukon Territory, NTS 104M/14W. The property is about 25 kilometres south of the past producing Mt. Skukum gold mine and 35 kilometres west of the highway connecting the Alaska Highway with the port of Skagway, Alaska. Access is by helicopter from Whitehorse, Yukon. The Eagle property is located in the Coast Mountains and exhibits rugged alpine terrain typical of this youthful, glacially sculptured region. The claims straddle a ridge topping out at just over 2300 metres elevation and extends down to 1300 metres in the upper valley of Jones Creek, which drains west into Partridge Lake. West Range Exploration Ltd. 2

3 The property consists of 4 claims totaling Ha. Tenure Number Claim Name Owner EAGLE EAGLE EAGLE EAGLE Map Number Good To Date Status Area 104M 2007/JAN/26 GOOD M 2007/JAN/25 GOOD M 2007/JAN/25 GOOD M 2007/JAN/25 GOOD B. Geology The Eagle Property is located along the southern margin of the Bennett Lake caldera, an Eocene volcanic cauldron which was originally identified by Wheeler (1961) and later described in some detail by Lambert (1974). It is part of a widespread Eocene magmatic province which includes mainly felsic volcanic rocks of the Sloko and Skukum Groups. The Skukum Group is distributed in two main subcircular volcanic cauldrons. The northern area lies mainly north of the Wheaton River in the Yukon, and includes the past producing Mt. Skukum gold mine, and two other significant gold-silver deposits (Goddell and Kuhn/Rainbow) and an antimony deposit (Becker-Cochran). The Mt. Skukum mine produced 77,790 ounces of gold from 233,440 tonnes of ore between 1986 and 1988 (Lang et al., 2003), and presently has a resource of 109,000 tonnes at 13.4 g/t Au. The Rainbow and Kuhn zones presently have a combined resource of 800,000 tonnes at 6.78 g/t Au and 248 g/t Ag (measured and indicated). The Goddell Gully deposit has an indicated resource of 320,000 tonnes at g/t Au and an inferred resource of 280,000 tonnes at 9.21 g/t Au (Tagish Lake Gold Corp., news release June 24, 2003). The Bennett Lake caldera underlies an area of approximately 15 x 20 kilometres and is bisected by the B.C. Yukon border west of Bennett Lake. Volcanic rocks of the caldera consist mainly of rhyolite to dacite ash-flow tuffs and breccias, with subordinate rhyolite, dacite, and andesite lavas. It is party encircled by a rhyolite ring-dyke system and surrounded by granitic rocks of the Coast Compex. No known gold deposits are associated with the Bennett Lake caldera, which has received almost no exploration in comparison with the Wheaton River area. The Eagle Property covers an 2500 x 900 metre volcanic centre which has intruded granite along the southern margin of the caldera ring-fracture complex. This centre (called Eruptive Centre V by Lambert, 1974) is a composite vent in which magmas of varying compositions erupted at different times. Early eruptions vented pyroclastic flows which accumulated as a green ash-flow tuff with rhyolite, dacite and accidental granite clasts as well as pumice. On the west side of the extrusive center, the tuffs are intruded by (and locally intrude) multiple andesite porphyry domes and necks which are locally autobrecciated along their margins. The andesite bodies range from 30 to 300 metres West Range Exploration Ltd. 3

4 across and weather in relief against the recessive tuff. The matrix of the andesite is characterized by intense iron oxide alteration. On the east side of the volcanic centre is a rhyolite dome which crops out over a 500 x 900 metre area. Outcrops weather deeply to rusty grey. The rhyolite is a flow-laminated rock with sparse glomeroporphyritic plagioclase and sanidine phenocrysts. Between the rhyolite dome and the andesite bodies the tuffs are cut by numerous finely laminated rhyolite to dacite dykes, which locally have gradational contacts with the tuff. The volcanic centre is surrounded by a broad zone of brecciated granite grading out into shattered granite over 400 metres. Shattered and brecciated granite are intruded by many rhyolite, dacite, andesite and dark grey tuff breccia dykes from 4-60 metres thick. The southern margin of the caldera is generally cut by a swarm of mauve rhyolite dykes and dark grey silicic rocks related to the ring fracture system. C. Mineralization Exploration in the Partridge Lake area began in 1979 when E&B Exploration Ltd. carried out a regional exploration program for uranium. Doron Exploration Ltd. acquired the Golden Partridge claims and conducted reconnaissance prospecting programs in A quartz-fluorite-pyrite-galena vein ( Eagle vein ) cropping out on the side of a ridge was located and channel sampled, returning a value of g/t Ag and 0.4 g/t Au over 0.3 m. Other quartz-chalcedony veins sampled further to the southeast returned assays of 22.7 g/t Ag and 0.2 g/t Au, and g/t Ag and 0.3 g/t Au. These veins are all located near the southern margin of the rhyolite dome described by Lambert (1974). About 1.1 km to the northeast, prospecting along the toe of a small glacier resulted in the discovery of a large, spectacuar quartz-sulfide boulder with native silver (electrum?) mineralization. A sample of the boulder returned a value of 44.5 g/t Au and 14,356 g/t Ag. No work has been done subsequent to this discovery to locate the source. It is conceivable that in the seventeen years since this discovery there has been sufficient glacial recession to uncover the source. About 2.6 to 3.5 km southeast of the Eagle vein, mineralized trending quartzchalcedony veins are hosted by granodiorite adjacent to rhyolite ring fracture dykes. The veins range from metres wide, and have been traced over 600 metres. Gouge zones up to 0.5 metres wide lie on both sides of the veins. Samples from the northern vein returned values up to 439 g/t Ag, while samples from the southern vein returned up 393 g/t Ag. Lead and zinc locally exceed a few percent, while gold values are low (<100 ppb). These veins may have been eroded below the level of significant gold deposition. D. Exploration Potential The known epithermal vein mineralization associated with Eruptive Centre V is in part spatially related to the rhyolite dome on its east side. High silver grades have been West Range Exploration Ltd. 4

5 obtained from outcropping veins in reconnaissance exploration, but detailed follow-up work has not been attempted. In particular, the types of models developed since the discovery and development of dome-associated epithermal systems such as El Peñón (see below) have not been applied in exploration of the Bennett Lake caldera. The discovery of bonanza-grade float east of the dome near the edge of a small glacier suggests that covered portions of the system may constitute the best target. The source of this float is an exciting target which may have been enhanced by recent glacial recession. E. References Lang, J., Rhys, D. and Naas, C. (2003): Structure and alteration related to gold-silver veins at the Skukum Creek gold deposit, southern Yukon. Yukon Exploration and Geology 2002, p Lambert, M.B. (1974): The Bennett Lake Cauldron Subsidence Complex, B.C. and Yukon Territory. Geological Survey of Canada Bulletin 227. Wheeler, J.O. (1961): Whitehorse Map Area, Yukon Territory. Geological Survey of Canada Memoir 312. Assessment Report: Property Name Mining Division(s) Golden Partridge Atlin Location NAD 27: Latitude: Longitude: UTM: NAD 83: Latitude: Longitude: UTM: NTS: BCGS: 104M14W 104M094 Title of Report Exploration Report on the Golden Partridge Property Affidavit Date Claim(s) Julia, Emily, Yak Operator(s) Owner(s) Author(s) Davidson, G.S. Report Year 1988 No. of Pages 33 Pages Off Confidential Commodities Search For Silver, Gold General Work Categories Geochemical West Range Exploration Ltd. 5

6 Work Done Geochemical Rock 48 sample(s) Elements Analyzed For Gold, Silver, Copper, Lead, Zinc, Molybdenum/Molybdenite, Antimony, Mercury Geological Summary The property lies on the southern side of the Bennett Lake Caldera Complex. The complex consists of two nested calderas, an eroded structural dome and a thick succession of pyroclastics and epiclastic rocks deposited during the Tertiary. Mineralized quartz veins are associated with rhyolite and andesite dykes in ring fracture systems within the caldera. Assessment Report: Property Name Mining Division(s) Golden Partridge Atlin Location NAD 27: Latitude: Longitude: UTM: NAD 83: Latitude: Longitude: UTM: NTS: BCGS: 104M14W 104M094 Title of Report Affidavit Date Claim(s) Operator(s) Owner(s) Author(s) Report Year 1988 No. of Pages Exploration Report on the Golden Partridge Property Emily, Julia Davidson, G.S. 20 Pages Off Confidential Commodities Search For Silver, Gold General Work Categories Prospecting Work Done Geochemical Rock 11 sample(s) Prospecting Prospecting Elements Analyzed For Gold, Silver, Platinum, Palladium, Copper, Nickel ha Geological Summary The property lies on the southern side of the Bennett Lake Caldera Complex. The complex consists of two nested calderas, an eroded structural dome and a thick succession of pyroclastics and epiclastic rocks deposited during the Tertiary. Mineralized quartz veins are associated with rhyolite and andesite dykes in ring fracture systems within the caldera. West Range Exploration Ltd. 6

7 El Peñón Model (from This block diagram shows the geology of the Quebrada Colorada deposit area. It was constructed with information from more than 250 drill holes. The geologic history inferred from this model and other studies in the El Peñón area indicate that approximately 60 million years ago a rhyolitic dome complex intruded a sequence of volcanic rocks (dacite flows, tuffs, and volcaniclastics). The rhyolitic dome developed from multiple phases of intrusive and extrusive activity. The different rhyolite phases have sources from several different pipe-like feeder structures similar to the Rhyolite IV Feeder depicted in the diagram. The Rhyolite IV Feeder is located adjacent to the Quebrada Colorada vein deposit, and the mineralized Doncella vein is found on the opposite side but within the margin of the rhyolite feeder. The heat generated by the intrusive activity produced a geothermal system of hot circulating water. These circulating hydrothermal fluids contained dissolved metals such as arsenic, antimony, lead, zinc, mercury, copper, silver, and gold. During episodic boiling events of the hydrothermal fluids the metals precipitated with quartz and carbonate into localized open spaces. Minable gold and silver ore bodies or shoots developed in the open spaces created by north-striking faults, such as Quebrada Colorada and Quebrada Orito. The ore shoots with the highest grade and best continuity at El Peñón developed where the north-striking faults cut volcanic layers (dacite and tuff) that are interleaved with the rhyolite units as depicted in the diagram. Future exploration will target other volcanic layers that are cut by the mineralized faults to increase the reserves and ultimately the mine life. West Range Exploration Ltd. 7