Mining Intelligence and News

15 Mile Project

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Mine TypeOpen Pit
  • Gold
Mining Method
  • Truck & Shovel / Loader
Mine Life... Lock
SnapshotPreviously identified as “Fifteen Mile Stream Gold Project”, the 15 Mile Project was proposed to be developed in association with the currently operating Touquoy Gold Project.

Since July 2023, the new look St Barbara team have re-designed 15-Mile to be developed independently of Touquoy. That project is now moving towards permitting.

Following the release of this PFS, St Barbara will now focus on preparation of updated environmental and social impact assessment for this new standalone design of the 15 Mile Project. The Feasibility Study engineering is intended to be ramped up as St Barbara sees progress towards Environmental Approval with commencement of development considered entirely achievable in mid calendar 2026.
Related AssetAtlantic Operation


St Barbara Ltd. 100 % Indirect
Atlantic Mining NS Inc, wholly owned subsidiary of St Barbara Limited, has 100% ownership of the tenements over 15 Mile (EL05889, EL52901 and EL10406).



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Deposit type

  • Vein / narrow vein


The 15 Mile (previously Fifteen Mile Stream) Project consists of Egerton-Maclean, Plenty, Hudson and 149 Deposits.

Individual mining operations, including mining at Fifteen Mile Stream, have focussed on quartz-vein hosted gold deposits within the Goldenville Formation, typically associated with the limbs and hinges of anticlines. This setting is often referred to as ‘Meguma style’ gold mineralization and a number of workers have drawn parallels with a similar style of gold mineralization in the Victorian Goldfields of eastern Australia (e.g. Christie et al, 1999) .

At Fifteen Mile Stream, the highest gold grades are typically associated with beddingparallel tabular quartz veins. However, the host rock material between quartz veins also carries significant gold grades. It is the quartz vein hosted gold mineralization augmented by disseminated style mineralization that forms the basis of a geological model associated with the ongoing exploration and development of the Fifteen Mile Stream gold deposit.

Mineralization at Fifteen Mile Stream is focused in the hinge of a regional anticline and generally conforms to a saddle-reef style model where veins and related alteration occur in bedding-parallel structures resulting from folding. Fold related strain is focused within the softer meta-mudstone units thus mineralization is generally controlled by stratigraphy, with bedding-parallel quartz veins and related alteration mainly confined to meta-mudstone intervals. True saddle-reef quartz veins do not occur within any of the mineralized zones. However a thick bedding-parallel quartz vein referred to as the ‘Big Bull Vein’ in the centre of the district is interpreted as a saddle-reef vein.

Gold mineralization within the FMS is largely hosted by bedding-parallel quartz veins that are buckled and folded with the enclosing sedimentary beds. Two main vein styles include massive milky white veins and laminated veins, the latter typically smoky in colour and characterized by vein-parallel inclusions. Weak wall rock alteration spatially associated with the veins includes carbonitization and, locally, sericitization. Associated sulphide mineralization includes arsenopyrite, pyrite and pyrrhotite with the pyrrhotite frequently hosting minor chalcopyrite. Arsenopyrite modally comprises trace amounts of around three percent and occurs as equant, subhedral grains 1-5mm in diameter.

Gold occurs as coarse (>1mm) grains in quartz veins and locally as finer (<1mm) grains in wall rock. Coarse gold in veins is commonly found at vein-wall rock boundaries and with sulphide minerals.

Anomalous gold values in the range of 0.1 to 4.0 gpt Au were frequently returned for intervals without any quartz veins or visible gold and the nature of this mineralization is not well understood. However, high gravity recovery for similar mineralization at the Beaver Dam and Touquoy deposits suggest the gold occurs as free gold, possibly associated with sulphide minerals.

Mineralization in the Hudson Zone is confined to the Egerton-McLean stratigraphy and is similar in character to that noted in the Egerton-McLean Zone i.e. coarse gold in veins and finer free gold in altered wall rock. The Fifteen Mile Stream Anticline in the Hudson Zone is overturned as in the Egerton-McLean Zone. However the fold in the Hudson area is tight with a narrow, angular hinge and lacks the complex decametre folds that characterized the Egerton-McLean Zone. The lack of folding in the hinge area results in a smaller mineralized zone due to the lack of repetition.

Historic drilling in the 149 East Zone documented a few auriferous intervals. Recent drilling in this area in late 2009 by Acadian (Graves, 2010) intersected a wide interval of predominantly green banded meta-mudstone similar in appearance to the Orient Mudstone in the hinge of the anticline. The core lacks abundant veining and alteration typically associated with mineralization in the Egerton McLean Zone. The historic mineralized intervals appear to be represented by minor dark meta mudstone in the recent drill holes. Notably, a grain of gold was present within the green banded mudstone in the absence of veins or alter-ation. As in the Hudson Zone the fold in this area is tight, relatively horizontal and does not show evidence of significant fold repetition.

The Plenty Zone occurs on the south limb of the Fifteen Mile Stream Anticline approximately 400 m southwest of the Egerton-McLean area. The mineralized zone is controlled by stratigraphy and bedding-parallel quartz veins that are steeply dipping. Gold was reported to occur in quartz veins and argillite (meta-mudstone) (Morris, 1986).



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CommodityUnitsAvg. AnnualLOM
Gold koz 56600
All production numbers are expressed as metal in doré.

Operational metrics

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* According to 2023 study.

Production Costs

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* According to 2023 study / presentation.

Operating Costs

OP mining costs ($/t mined) CAD 4.12 *  
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* According to 2023 study.

Project Costs

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