West Ansil
West Ansil
The West Ansil project is located approximately 15 kilometres to the northwest of Rouyn-Noranda, Quebec, Canada. The deposit is located at the southern limit of the West Ansil property with the adjacent Lac Duprat property to the south. The properties presently under agreement with Inmet Mining Corporation are owned 100% by Falconbridge Limited and are part of a group of properties under Option by Alexis Minerals Corporation since May 2004.
Regional Exploration Approach
During recent years, a Gocad 3D geological model of the Central Camp was built and a number of targets have been generated by the Falconbridge exploration team using different queries within the Gocad platform. Two of the targets generated (P-29/P-30) were prioritized for followup to the southwest of the Ansil deposit. These targets were characterized by the presence of a significant alteration zone within the Rusty Ridge Formation in historical holes that had not reached the Lewis and the Corbet contacts. These contacts host respectively the Ansil and the Corbet deposits. Moreover, this alteration was located near the junction of two synvolcanic faults (EW2 and VC faults).
Discovery
The West Ansil discovery was made in March of 2005 while testing a Gocad (P-29/P-30) developed target area. The discovery hole, AN-05-03, was testing an off-hole anomaly previously detected in hole AN-05-02 which had intersected significant copper stringers and associated chloritisation, including 2.78% Cu over 5.80 metres and 1.20% Cu over 7.30 metres. The discovery hole, AN-05-03, intersected a massive sulphide zone followed by a stringer zone grading 1.28% Cu and 0.23% Zn over 26.15 metres. This discovery of the Lower Zone has been followed by the discoveries of two other lenses, namely the Middle and the Upper Zones. The West Ansil deposit is located within the Rusty Ridge Formation. The deposit lies at or near an andesite-basalt contact within the Rusty Ridge mafic rocks and is thus located stratigraphically above the Ansil deposit and below the Beecham Breccia, representing the first known massive sulphide discovery at this stratigraphic horizon.
Resources
The West Ansil resources have been divided into two categories (indicated and inferred). The rounded Indicated Resource of the West Ansil (Middle Zone) is estimated at 0.53 MT grading 3.4% Cu, 1.4 g/t Au, 9.2 g/t Ag and 0.4% Zn.
The rounded Inferred Resource of the West Ansil deposit has been estimated at 0.60 MT grading 3.3% Cu, 0.3 g/t Au, 5.9 g/t Ag and 0.2 % Zn.
Resource Recommendation
The Resource evaluation recommended that prior to any preliminary feasibility study for the West Ansil deposit, the inferred resources should be upgraded to at least the ‘‘Indicated’’ category by conducting more drilling in the zones that have been identified. Additional drilling in the Middle Zone would aid in the interpretation of the different sets of dykes and their implication on the internal dilution.
Deposit Potential
Exploration targets in and around the West Ansil VMS deposit have been tested during the last 2 years with no additional discovery. The Resource appears limited to the current size. A “back of the envelope” review of potential economics of the deposit has been undertaken with reasonable general assumptions and for Cu-metal prices at 1.50, 2.50 and 3.50 US$/lbCu.
Results are quite favourable at high Copper metal prices, but fall away immediately with lower prices and with generally accepted long-range metal price estimates. It appears very clear that the economic viability of the discovery is highly dependent on mining of the deposit during a high Cu-metal cycle, such as the one we are currently experiencing.
Exploration approach
Highest grade, and least defined area of the deposit, occurs between the 350-m to 500-m levels. Grade in this area is estimated at 5% Cu with stringer zones ranging between 5% and 18% Copper over mineable intervals.
A 3-D model of the deposit and geology in the area of the deposit is being developed as part of a M.Sc. Research program in order to advance current thinking and modeling. Further exploration will be planned upon its completion.