Overview

Mine Type	Open Pit
Stage	Permitting
Commodities	Gold
Mining Method	Truck & Shovel / Loader
Mine Life	...
Snapshot	On October 22, 2024, following a successful trial of sorting technology on Cochrane Hill’s gold ore, St Barbara is evaluating an alternative design to process the ore at the proposed 15-Mile process plant, eliminating the need for a processing plant or tailings management facility at Cochrane Hill. Metallurgical testing is almost complete, and an options review will ensure the optimal design is chosen. The redesign is expected to be finished by Q4 FY25. The Environmental Assessment document will be delayed until there are positive indications of improved permitting and regulation from the Nova Scotia Department of Environment and Climate Change (NSECC).

Deposit type

• Vein / narrow vein
• Orogenic
• Mesothermal

Summary:

The known deposits within the Atlantic operation area are considered to be examples of turbidite-hosted, orogenic mesothermal gold deposits.

Strata of the Meguma Terrane in eastern mainland Nova Scotia include the basal greywacke-dominated Goldenville Group and the overlying, finer-grained, argillitedominated Halifax Group. Cochrane Hill is hosted in the basal Goldenville Group.

The Cochrane Hill property encompasses a section of the northeast-trending Cochrane Hill anticline which can be traced for at least 28 km from a position approximately 14 km west of the Cochrane Hill deposit, to approximately 12 km east of the Cochrane Hill deposit. The Cochrane Hill anticline is a tight to isoclinal fold in the vicinity of the Cochrane Hill deposit, overturned with both limbs dipping to the north at between 55° and 80°.

The host interbedded argillite and greywacke sequence may either represent sediments of the Moose River Formation or the Tangier Formation.

Structure
There appears to be very little disruption of the mineralised zone by post-mineralization faulting. Although physical evidence in core is limited, historical geophysical data along with observations from logging geologists suggest a steep northwest-trending fault just west of line 3000E could divide the property into a western domain and an eastern domain, which supports a metallurgical divide as seen in geostatistical evaluations.

Metamorphism
Lithologies in the area have been metamorphosed to amphibolite (staurolite) facies with development of biotite schists after argillite protoliths and porphyroblastic textures in fine-grained greywacke and argillite.

Mineralization
Mineralization is in the form of a tabular zone of parallel, planar quartz veins in a wellbedded argillite and greywacke protolith, dipping steeply to the north at approximately 70°, parallel to bedding in the southern limb of the Cochrane Hill anticline.

Gold mineralization occurs over true widths of up to 60–70 m, within which better grade material (e.g., >0.8 g/t Au) is persistent over true widths varying from 5–30 m. The base of the gold mineralization is relatively sharp in terms of grade, but the hanging wall contact is less defined, with an erratic distribution of weakly anomalous grades and occasional >1 g/t Au grades. The mineralization has been defined over a strike length of 1,500 m and down to a vertical depth of 300 m.

Gold mineralization occurs within quartz veins and within biotite schist (after argillite) and metagreywacke host rock. Mineralization is associated with sulphides, including arsenopyrite, pyrite and pyrrhotite and lesser galena and sphalerite.

The known deposits within the Atlantic operation area are considered to be examples of turbiditehosted, orogenic mesothermal gold deposits.

Mining Methods

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Comminution

Crushers and Mills

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Processing

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Production

Operational metrics

Personnel

Job Title	Name	Profile	Ref. Date
.......................	.......................		Nov 19, 2024
.......................	.......................		Nov 19, 2024