Mineralization
The Red Chris deposit is about 3.4 km in strike length, 0.3 km in width and over 1.3 km in vertical extent. There are two main zones, East and Main. The Main zone is 1,200 m in strike length, 300 m in width and has been drill tested to 1,300 m depth. The East zone is 1,200 m in strike length, 300 m in width and has been drill tested to 1,400 m depth.

The zone of >0.2% Cu%, is >3 km long, oriented west–southwest–east–northeast and can reach 650 m in width. Quartz–magnetite stockworks are overprinted by higher gold and copper grades. The highest copper–gold grades occur in and around the P2 porphyries and associated igneous breccias.

Mineralisation consists of thin wavy or thicker planar quartz veins containing chalcopyrite, bornite and magnetite; these minerals are also disseminated outside the veins. In the upper part of the deposit, the bornite-rich mineralisation was overprinted by sericite and clay alteration and associated sulphidation. Gold occurs as microscopic inclusions in the copper sulphides, and occasionally as free grains in high-grade zones.

Molybdenite occurs locally in quartz veins, especially deeper and outside the high-grade core.

DEPOSIT TYPES
Overview
Red Chris is considered to be an example of a porphyry copper deposit with elevated gold values, characterized by the composition of its host rocks, its alteration, and its copper–gold signature, with only minor molybdenum. It is cla ........

The Red Chris Operations are a copper–gold open pit mining operation located in northwest British Columbia, Canada.

Open pit operations are conducted using conventional methods and a conventional truck and shovel fleet.

Geotechnical Considerations
The pit design parameters for Red Chris are designed to control bench scale stability and rockfall issues more than the global stability of the pit walls. In 2020, the geotechnical parameters were updated based on geotechnical and operating history at the Project.

Golder defined six geotechnical domains within the open pit. Recommended inter-ramp angles ranged from 41.9–52.8º. These were adjusted to take the pit ramps into account, leading to designed slope angles from 34–46º.

The greatest area of concern for stability is on the southern wall and in particular the Bowser Lake Group sediments. The results of the overall slope stability analyses indicated that the proposed south wall design is expected to exhibit adequate factors of safety with respect to overall slope circular type failure that involves failure from the crest of the scope through the South Boundary Domain and South Domain rock mass.

Two areas that show a factor of safety risk are associated with the Bowser Lake Group sediments near the pit crest, and are only problematic with elevated pore water pressures.

The benches are expected to be relatively free draining, and significant pore pressures a ........

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