The Murray Brook sulphide mineralization is classified as a volcanogenic massive sulphide deposit (P., W., C., Shanks III, et al) 2009. This type of deposit is characterized by massive to semi-massive iron sulphide minerals including variable amounts of base metals and precious metals. This type of deposit is well studied and documented. Genetically the deposits are coeval with felsic volcanic centres, and are generally lens-like, parallel to the stratigraphy, with a discordant hydrothermal “pipe” at the stratigraphic base of the sulphide accumulation.

As is well illustrated by the discovery of the Murray Brook deposit, heavy mineral and soil geochemical surveys are an effective search tools. Geophysical surveys including magnetic, electromagnetic, induced polarization/ resistivity, and gravity surveys are also effective exploration tools for concealed deposits.

The Murray Brook deposit is hosted by sedimentary rocks of the Charlotte Brook Member in the lower part of the Mount Brittain Formation. The upper felsic volcanic member of the Mount Brittain Formation is host to the Restigouche deposit, some 10 km to the west. The Mount Brittain Formation is believed to be equivalent of the Spruce Lake Formation which hosts the Caribou Mine, ten kilometres to the east.

The sulphides are massive to semi-massive, locally banded and pyrite-rich. The deposit has a 1 to 3 m wide halo composed of chloritized sedimentary rocks containing disseminated pyrite. The hanging wall is moderately chloritic and is locally intensely deformed. The footwall consists of fine grained felsic tuff, and tuffaceous sediments with moderate to strong chlorite and sericite alteration.

Sulphides are mainly fine grained, massive, vaguely laminated pyrite with disseminated and banded sphalerite, chalcopyrite and galena, with minor tetrahedrite, covellite, marcasite and arsenopyrite.

The Murray Brook deposit is relatively shallow in depth and lends itself to conventional open pit mining methods. A single open pit will be developed that will have a maximum depth of approximately 340 m from the highest point (550 masl) to lowest point (212 masl).

The mine production schedule consists of one pre production year for pre-stripping and then ten years of actual mine production.

The target milling rate is approximately 2,000,000 tonnes per year, or approximately 6,000 t/day. Daily mining rates of mineralized material and waste combined will range from 12,000 t/d to 32,000 t/d and average about 27,000 t/day.

Run-of-mine mill feed is dumped directly to a primary crusher equipped with a rock breaker. Crushed material discharges to a surge pocket and is delivered via an apron feeder and conveyors to a stockpile.

Feed to the semi-autogenous grinding mill (SAG mill) is withdrawn from under the stockpile by belt feeders and conveyed to the mill at a rate controlled by a weightometer located on the mill feed belt.

The grinding circuit consists of a SAG mill followed by a ball mill operating in closed circuit with hydrocyclone classifiers to produce a ground product at approximately 80% passing 30 microns for flotation.

Cyclone overflow slurry from the grinding circuit is fed via a conditioning tank to rougher/scavenger flotation cells comprised of sequential copper, lead, and zinc circuits. Rougher concentrates are reground and cleaned in three stages to produce saleable copper, lead and zinc concentrates. Cleaner scavenger tailings from all circuits are directed to tails along with the final rougher scavenger tailings.

The concentrates are thickened in a conventional thickener and filtered for shipment.