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Canada

Kitsault Valley Project

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Overview

Mine TypeUnderground
 Archived Information
Commodities
  • Gold
  • Silver
  • Copper
  • Lead
Mining Method
  • Longhole open stoping
Backfill type ... Lock
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SnapshotThe Kitsault Valley Project contains the Dolly Varden property with silver resources, the newly acquired Homestake Ridge property with gold, silver, copper and lead resources, and the Big Bulk property, a copper-gold porphyry system.

The former owner of the Homestake Ridge project completed a previous Preliminary Economic Assessment on the project with robust economics. This historic NI 43-101 compliant technical report is dated May 29, 2020.

Dolly Varden has published a technical report and updated mineral resource estimate for the combined Kitsault Valley project with an effective date of 28 September 2022.

The final holes of Dolly Varden Silver's 2024 drill programme at its Kitsault Valley project have returned high grade results. The company is working towards a future resource update and preliminary economic assessment.

Owners

SourceSource
CompanyInterestOwnership
Dolly Varden Silver Corp. 100 % Indirect
Dolly Varden Silver Corp. owns 100% of the Kitsault Valley project.

Deposit type

  • Epithermal
  • Stratabound
  • Vein / narrow vein
  • VMS

Summary:

The Kitsault Valley Project contains the Dolly Varden property and the Homestake Ridge.

Dolly Varden Deposits
Exhalative stratiform silica-sulphide-rich mineralization containing variable amounts of quartz, chalcedony, barite, carbonate, jasper, galena, sphalerite, ruby silver, and other silver bearing minerals. This mineralization is observed in the Dolly Varden Torbrit (DVT) horizon at North Star and Torbrit.

Exhalative stratiform pyrite, sphalerite, galena, chert, carbonate-rich mineralization at the Sault prospect and in the upper portion of the Trout Horizon. Stratabound, infill and replacement Ag-sulphosalt-rich mineralization in the lower portion of the Trout Horizon.

Quartz-silica, carbonate and variably barite-rich epithermal Ag mineralization containing low to moderate amounts of galena, sphalerite and pyrite accompanied by lesser tetrahedrite, pyrargyrite, argentite/acanthite and local native silver. Colloform to crustiform banded chalcedony, quartz and bladed carbonate or barite textures are common. Hydrothermal brecciation, sealed by later gangue and sulphide, and cut by late-stage veining is present in parts. Epithermal mineralization occurs as structurally hosted veins and fissure fills at Wolf, Kitsol and Dolly Varden. At Torbrit mineralization consists of a combination of Ba-rich semi-conformable pod-like stratabound infills, with sheet-like veining, and in close proximity to reworked debris-style mineralization, and local stratiform lenses of thin-bedded barite and sinter-like silica-rich exhalate.

Quartz-sericite-pyrite altered zones containing Cu-Ag- (+/-) Au mineralization in quartz-sulphide stockwork, hydrothermal breccias and veins. This mineralization contains chalcopyrite, sphalerite, galena and minor sulphosalt and tends to be enriched in Cu relative to Pb and Zn, while hosting elevated Ag (+/- Au). As/Sb ratios are higher than in the epithermal or stratiform types. Pervasive quartzsericite-pyrite alteration is observed at the Gold Belt prospect and sericite-pyrite (with lesser quartz) alteration bounds the North Star deposit. Potassium feldspar alteration is observed within the Red Point mineralized zones.

Homestake Deposits
Diverse mineralization styles on the Homestake Ridge include stratabound sulphide zones, stratabound silica-rich zones, sulphide veins, and disseminated or stockwork sulphides.

Mineralization displays characteristics of both epithermal gold and VMS deposition. Stratabound and vein (or replacement) mineralization is present that contains values in Ag, As, Au, Cu, Hg, Pb, Sb and Zn. The property geology is considered to be favourable for the discovery of “Subaqueous Hot Spring Au-Ag” or “Low Sulphidation Epithermal Au-Ag” type deposits.

The main zones of the Homestake Ridge deposit are the Homestake Main, Homestake Silver, and Silver Reef. The Homestake Main is the more copper-rich of the zones, with both gold-rich and silver-rich variants and an apparent trend of increasing copper grade with depth. The Homestake Silver zone is primarily silver with elevated lead values, and South Reef is essentially high-grade gold, with minor copper and lead.

The Homestake deposits are commonly vertically zoned from a base metal poor Au-Ag-rich top to an Ag-rich base metal zone over a vertical range of 250 m to 350 m. The silver-galena-sphalerite veins of the Homestake Silver Zone exhibit many of these features.

Homestake Main Deposit
The Homestake Main deposit consists of a series of silica to silica-carbonate-chlorite altered lenses and hydrothermal breccias, which have a northwest strike and dip moderately northeast at slightly steeper than the topographic dip-slope. Gold and silver mineralization occurs with pyrite, chalcopyrite, and lesser galena and sphalerite in stronger areas of silica alteration or hydrothermal brecciation within zones of sericite-pyrite altered feldspar-hornblende phyric volcanic rocks. Only along the southwestern flank of the Homestake Main deposit does lower grade gold mineralization penetrate up into the overlying package of basinal filling volcano-sedimentary and andesitic rocks which comprise the “hanging wall” sequence. Native gold along with pyrargyrite and acanthite have been observed hosted within quartz veins and quartz-carbonate hydrothermal breccias in drill core.

The Homestake Main deposit as currently known is about 700 m long and has been traced downdip by drilling for a distance of approximately 500 m. At the surface, the northwestern extent of the mineralization is obscured by a glacier; while to the southeast surface geochemistry indicates that the zone continues towards the Homestake Silver deposit 700 m to the southeast. Widths of the Homestake Main Zone vary up to about 60 m (approximate true width) and are defined by assay grades due to the diffuse nature of the mineralization.

Grades for gold typically range from 0.1 g/t Au to 2 g/t Au with some intercepts measuring into the hundreds of grams per tonne and averaged at 7.75 g/t Au. Silver grades are generally in the 1.0 g/t Ag to 100 g/t Ag range but can be as high as hundreds and even thousands of grams per tonne. The average silver grade in the HM is 68.6 g/t Ag. Copper grades vary from parts per million to several percent, with mean grades observed to increase significantly with depth.

Homestake Silver Deposit
Homestake Silver Deposit is located 300 m to the southeast of the Homestake Main zone, the Homestake Silver deposit is comprised of a series of northwest trending, vertically to sub-vertically dipping hydrothermal breccias. Mineralization occurs as galena, sphalerite and silver in contrast to the gold enriched chalcopyrite seen the Homestake Main deposit. Modelling indicates that the Homestake Silver deposit can be traced over 700 m strike and 550 m down dip.

The Homestake Silver zone comprises a cluster of parallel structurally controlled zones, striking approximately 140° with near-vertical dips. The individual sub-zones in the Homestake Silver zone are narrower than the Homestake Main zones on average, with true thickness rarely exciding three metres. The Homestake Silver zone has been traced by drilling for a total vertical extent of approximately 600 m, along a strike length measuring just under 800 m.

Silver grades at Homestake Silver average 154 g/t Ag, approximately double that of the HM (68.6 g/t Ag) and 26 times that of SR (5.8 g/t Ag). Gold grades at Homestake Silver typically range up to several g/t Au and averaged 3.5 g/t Au in the samples contained within the interpreted zone boundaries. Copper content is comparatively low, however, geochemically significant, and generally measures between 10 ppm Cu and 500 ppm Cu. There are elevated levels of lead and zinc, typically measuring in the 10 ppm to 1,000 ppm range, with some intercepts assaying as high as several percent lead and/or zinc.

South Reef Zone
The South Reef deposit is located approximately 800 m to the south-southwest of the Homestake Silver deposit. Gold mineralization is variably associated with strong quartz-chlorite alteration, pyrite and minor base metal sulphides interspersed with intervals of sericite and pyrite alteration in two en-echelon, northwest-trending sub-vertical mineral zones that can be traced with drilling for over 250 m strike-length and 250 m dip. Several base-metal enriched intercepts are identified up-section from the gold-enriched zone but have yet to be fully defined by drilling.

The South Reef zone is comprised of two narrow sub-parallel tabular bodies which strike at approximately 120° to 130° and dip 70°NE to 80°NE. To date, only twelve holes have intersected significant mineralization, as such characterization of the structure and grades is preliminary. The zones measure one metre to three metres in thickness and have been traced for approximately 300 m vertically and 400 m along strike. Silver grades at South Reef average 5.8 g/t Ag in the vein samples.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

Milling equipment has not been reported.

Processing

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Production

CommodityProductUnitsAvg. AnnualLOM
Gold Metal in conc./ doré koz 509
Silver Metal in conc./ doré koz 6,930
Copper Metal in concentrate M lbs 7.3
Copper Concentrate kt 11
Lead Metal in concentrate M lbs 4
Lead Concentrate kt 6
Gold Equivalent Metal in conc./ doré koz 45590

Operational metrics

Metrics
Daily ore mining rate  ....  Subscribe
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Ore tonnes mined, LOM  ....  Subscribe
* According to 2020 study.

Production Costs

CommodityUnitsAverage
All-in sustaining costs (AISC) Gold USD  ....  Subscribe
Assumed price Lead USD  ....  Subscribe
Assumed price Copper USD  ....  Subscribe
Assumed price Silver USD  ....  Subscribe
Assumed price Gold USD  ....  Subscribe
* According to 2020 study / presentation.

Operating Costs

CurrencyAverage
UG mining costs ($/t mined) USD  ....  Subscribe
Processing costs ($/t milled) USD  ....  Subscribe
G&A ($/t milled) USD  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe
* According to 2020 study.

Project Costs

MetricsUnitsLOM Total
Initial CapEx $M USD  ......  Subscribe
Sustaining CapEx $M USD  ......  Subscribe
Closure costs $M USD  ......  Subscribe
UG OpEx $M USD  ......  Subscribe
Processing OpEx $M USD 71.9
G&A costs $M USD 48
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Income Taxes $M USD  ......  Subscribe
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Gross revenue (LOM) $M USD  ......  Subscribe
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After-tax Cash Flow (LOM) $M USD  ......  Subscribe
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Pre-tax NPV @ 7% $M USD  ......  Subscribe
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After-tax NPV @ 5% $M USD  ......  Subscribe
After-tax NPV @ 7% $M USD  ......  Subscribe
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Required Heavy Mobile Equipment

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Personnel

Mine Management

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Aerial view:

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