MINTO/CARMACKS COPPER-GOLD PROPERTIES

Geological Overview

BCGold’s Minto/Carmacks Copper-Gold Properties are strategically situated in the Carmacks Copper-Gold Belt, centered some 220 kilometres northwest of Whitehorse, Yukon. This northwest-trending belt lies along the eastern margin of the Yukon-Tanana Composite Terrain, which is composed of several metamorphic assemblages and batholiths.

Intermediate to felsic intrusive and meta-intrusive rocks of the early Mesozoic Granite Mountain Batholith underlie much of the area and are interpreted to be intrusive into the Yukon-Tanana Terrane (Gordey and Makepeace, 1999). The batholithic rocks are in fault and/or intrusive relation with an unnamed package of altered mafic volcanic rocks to the northeast, and are unconformably overlain by sedimentary rocks and volcanic flows of the Late Cretaceous Tantalus Formation and Late Cretaceous Carmacks Group, respectively. Regional structure is poorly understood because outcrop is very sparse (<1%) and the area is unglaciated and deeply weathered.

BCGold Corp. is the largest landholder in the Carmacks Copper Gold Belt. Its 17 Minto/Carmacks Copper-Gold Properties are strategically located proximal and adjacent to Capstone Mining Corp.’s Minto Mine, a conventional flotation open pit copper mine that commenced commercial production on October 1, 2007, and Western Copper Corp.’s Carmacks Copper Project, located 52 kilometres to the south. Western Copper Corp.’s Carmacks Copper Project is currently in the permitting stage and the company is planning for an open pit, heap leach operation. BCGold Corp.’s Carmacks Copper-Gold Properties were staked over areas with similar geological, geochemical and geophysical characteristics known to reflect near-surface, high-grade structurally controlled copper-gold mineralization.

The Minto Deposit*

The high grade Minto copper-gold-silver mine is Canada’s newest mine, reaching commercial production on October 1, 2007. The deposit was discovered in 1973 and actively explored and evaluated in the early 1970s and 1990s but not developed until 2005-2008.

The Minto deposit is hosted by Mesozoic Age plutonic rocks of the Granite Batholith (~197Ma), which is interpreted as intrusive into the Yukon-Tanana Terrain. The Granite Batholith is composed of primarily massive granodiorite with very discrete, localized zones of foliation. The Minto deposit itself lies in the near flat-lying hinge of a broad north trending synform defined by the warping of this foliation about an axis which passes through the deposit.

There are no apparent deposits analogous to the Minto deposit on a world-wide basis, except perhaps the nearby Carmacks copper deposit. Capstone Mining Corp. is currently working on the basis of Minto being a variant of the IOCG class of deposits. Whatever its origin, the Minto deposit is hosted in granodiorites and mineralization is characterized by a bornite-chalcopyrite-magnetite rich core grading outward to a chalcopyrite-rich but bornite-magnetite poor eastern periphery. Magnetite content ranges to 30+%, but averages 5-10%. Pyrite is either absent or present in very low concentrations and is confined mostly to the magnetite-poor eastern periphery. Mineralization is confined to the zones of foliation where copper sulphide mineralization is disseminated and bleb to stringer like, preferentially orientated along foliation planes. Copper can locally grade up to 20+% while gold grades are frequently in the 1-2 g/t range. Gold is found throughout the deposit but is most strongly associated with bornite, although rare coarse free gold has been reported with grades exceeding 500g/t Au.

Visible alteration is sharply confined to foliated rocks with secondary potassium feldspar and abundant secondary biotite, and local silicification. Structural control of mineralization is evident on a micro and macro scale, with mineralization confined to multiple, flat-lying deformation zones in sharp contact with barren, but geologically identical granodiorite. Internal foliation is often at an angle to the overall foliated zones, and small scale parasitic folds internal to the foliated zones are evident. There is large scale open folding of the foliated zones and later sub-vertical structures may be upgrading the mineralization.

Since acquiring control of the Minto deposit in 2005, Capstone Mining Corp. has been undertaking an aggressive exploration program that has resulted in the discovery of at least one new commercial deposit, as well as several other significant zones of mineralization that offer commercial potential.

* Abridged from Geological Association of Canada, Québec 2008, Abstract, vol. 33, p. 140.

Carmacks Deposits

Western Copper Corp. has defined 14 copper zones within its Carmacks Copper Project, encompassed by BCGold’s Carmacks Block of mineral claims and situated 52 km south of the Minto deposit. The deposit area is underlain by intrusive and meta-intrusive rocks of the Granite Mountain Intrusion. Compositions range from granodiorite to diorite. These rocks are equigranular to porphyritic, and massive to moderately foliated.

The estimated mineral resource (and reserve) is confined to the No. 1 Zone, which extends over a 700 m strike length and at least 450 m down dip. The deposit is open at depth and is oxidized to 250 m in depth. Copper-gold mineralization at Carmacks Copper is hosted by feldspathicbiotite- hornblende-quartz gneisses. The majority of the copper found in oxide portion of the No. 1 Zone is in the form of the secondary minerals malachite, cuprite, azurite and tenorite (copper limonite) with very minor other secondary copper minerals (covellite, digenite, djurlite). Primary copper mineralization is restricted to bornite and chalcopyrite.

For additional details on the Minto and the Carmacks Copper Project, please see the websites for Capstone Mining Corp. ( www.capstonemining.com ) and Western Copper Corp. ( www.westerncoppercorp.com ).

The following technical reports describing the geology of these deposits and the region in more detail are available:

• Minto Phase IV Pre-Feasibility Technical Report; Prepared for Minto Explorations Ltd.
  by SRK Consulting Engineers and Scientists, December 15, 2009.

http://capstontemining.com/i/pdf/2009-12-15_MintoPhaseIVPFSTechReport_01.pdf

• High-grade hydrothermal copper-gold mineralization in foliated granitoids at the Minto mine, central Yukon, 2009., Shawn Hood and Kenneth Hickey, Mineral Deposits Research Unit, University of British Columbia; Maurice Colpron, Yukon Geological Survey and Brad Mercer, Capstone Mining Corporation, 2009. In: Yukon Exploration and Geology 2008, L.H. Weston, L.R. Blackburn and L.L. Lewis (eds.), Yukon Geological Survey, p. 137-146.

          http://www.geology.gov.yk.ca/pdf/14-hood.pdf

• Early Jurassic porphyry(?) copper (-gold) deposits at Minto and Williams Creek, Carmacks Copper Belt, western Yukon., Reza Tafti and James K. Mortensen¹, Mineral Deposit Research Unit, Earth & Ocean Sciences, University of British Columbia²
  
  http://www.geology.gov.yk.ca/publications/yeg/yeg03/21_tafti.pdf
   
• Nature and origin of copper-gold mineralization at the Minto and Williams Creek deposits, west-central Yukon: Preliminary investigations, 2003., J. K. Mortensen and R. Tafti, document.
  
  http://www.geology.gov.yk.ca/publications/yeg/yeg02/13_mortensen_tafti.pdf  

To date, BCGold has discovered 7 significant “Carmacks-style” copper-gold mineralized zones on the ICE and WS properties that lie just south of the Carmacks deposit.

ICE Zone

At the ICE claims in 2007, situated seven kilometres southward of the Carmacks deposits, rock samples were collected from a series of granitic outcrops over a partially exposed strike length of 80 metres. The granitic rock displays discrete zones of weak to moderate foliation dipping 25-30° to the northeast, locally containing significant amounts of “Carmacks-style” copper oxide and gold mineralization with samples assaying up to 1.83% Cu, 0.25 g/t Au and 1.28% Cu, 0.41 g/t Au. The oxide copper mineralization occurs in the form of malachite with secondary biotite (potassic) alteration. 

Follow-up drilling at the ICE zone in 2007 intersected 2 discrete zones of copper-oxide mineralization. The first copper horizon was approximately 5 metres thick and grades up to 0.46% Cu. The horizon is described as foliated megacrystic biotite rich granodiorite with 5-10% malachite on fractures and along the foliation. A second copper-oxide horizon less than 2 metres thick and grading up to 0.26% Cu was intersected further down-hole and is characterized by 5% malachite on fractures and along foliation planes (for full details of the drilling please see  BCGold press release November 22,, 2007). Ice Zone copper-gold mineralization occurs along the eastern flank of a bulls-eye aeromagnetic high signature, measuring roughly 1,000 metres by 700 metres in size. Highly anomalous copper-in-soil samples, with values ranging from 281 to 935 parts per million (ppm) Cu have been recorded 300 metres westward of the Ice Zone rock samples, along the northwest margin of this same magnetic anomaly.

WS Property

In 2008, BCGold drilled 5 holes in 1,235 metres on the WS Property along the Western Copper property boundary, targeting 5 discrete Induced Polarization (I.P.) geophysical and/or copper mobile metal ion (MMI^TM) geochemical trends defined in 2008 by BCGold. Drill hole WS08-09B intersected 2 near-surface copper sulphide horizons over 63.1 metres that averaged 0.17% Cu (containing 23.6 m averaging 0.34% Cu). This intercept is reflected by a weak copper MMI^TM anomaly coincident with a pronounced, 2 kilometre long linear I.P. geophysical anomaly. This I.P. anomaly is along strike and 1 kilometre from Western Copper’s Zone 14. Western Copper intersected 79.7 metres averaging 0.23% copper in Zone 14 during its 2007 drill program (Western Copper News Release – November 22, 2007). BCGold’s drill holes WS08-10, 11 and 12 did not intersect any significant copper mineralization.

Copper mineralization in drill hole WS08-09B occurs in 2 discrete and relatively homogenous intervals of foliated horneblende schist within a white mega-crystic alkali feldspar granodiorite. Mineralization in the upper interval, which averages 0.13% copper over 20.0 metres between 46.0 – 66.0 metres, consists primarily of pyrite and chalcopyrite intermixed in foliated schist. Massive chalcopyrite occurs along the edges of carbonate stringers and malachite occurs along fractures.

Chalcopyrite mineralization occurs in a similar fashion in the lower mineralized interval between 85.5 and 109.1 metres, and averages 0.34% copper over 23.6 metres. Chalcopyrite and fracture controlled malachite occur intermixed with pyrite in foliated hornblende schist. Massive chalcopyrite rims carbonate stringers and larger chalcopyrite grains display red oxidized rims. Propylitic (chlorite, epidote, carbonate, and sericite) alteration with secondary hematite and weak alkali feldspar alteration predominates.
 

last updated: February 03, 2010