The Spectrum-GJ copper-gold property is situated approximately 30 km west of Imperial Metals’ Red Chris Mine in the Golden Triangle of northwest British Columbia. Infrastructure and access to the property are excellent as the property is crossed by Highway 37, the 287 kV Northwest Transmission Line, as well as several forestry roads and winter trails.
In April 2017, Skeena Resources released the results of a Preliminary Economic Assessment (PEA) for the project. The PEA focuses on two resources that are approximately 14 km apart, the porphyry copper-gold Donnelly resource at GJ and the porphyry gold-copper Central Zone at Spectrum. The technical study is based on a proposed open-pit mine with a staged approach to production, starting with 10,000 tpd at Donnelly and eventually ramping up to 30,000 tpd with additional ore coming from Spectrum. The project has estimated initial capital expenditures of C$216 million. Skeena is actively seeking a partner to advance the Spectrum-GJ project.
Sandstorm’s royalty interest covers the Spectrum property, where two main styles of gold and copper mineralization are present: structurally-hosted, high-grade, sulphide-gold (>4.0 g/t gold) and bulk tonnage, disseminated, porphyry-style gold-copper mineralization. The Central Zone mineral resource at Spectrum consists of a broad zone of low-grade porphyry gold-copper mineralization cut by at least four sub-parallel steeply dipping higher-grade gold mineralized structures. The deposit remains partially open along strike and down dip. A January 2017 resource estimate for the Spectrum Central Zone consists of 31.2 Mt of ore at grades of 0.9 g/t gold, 2.6 g/t silver and 0.10% copper in the Indicated category and another 29.8 Mt of Inferred Resources at grades of 0.5 g/t gold, 1.4 g/t silver and 0.12% copper. The resource was calculated using a 0.4 g/t AuEq cut-off grade.
Skeena is seeking a partner to assist in the development and financing of the Spectrum-GJ property.
A Preliminary Economic Assessment was filed for the Spectrum-GJ project. The after-tax NPV (8%) is estimated to be C$314.1 million with an IRR of 20.6%.