DOLLY VARDEN PROJECT
Dolly Varden Silver Corporation owns 100% of the Dolly Varden Mines historic silver property. The current favourable price of silver has renewed investor interest in this most historic of the silver mines in the Northwestern BC region. The property is best considered an advanced exploration stage property with well understood targets. Mine restarts will require the discovery of additional silver mineral resources and the confirmation of historic mineral resources that were known at the cessation of mining in 1959.
Geological work commissioned in the period 1979 to 1990 established the common geological characteristics of the major silver deposits and occurrences in the upper Kitsault Valley. The rock formations and the style of the mineralization and alteration on the Dolly Varden property share strong similarities to the nearby Eskay Creek deposit, which is an exceptionally rich gold and silver deposit, located 100 km north of the Dolly Varden Property.
- 8,800 hectares (88 km2)
- 100% owned
- Four historically active mines
- Under-explored sectors – only 3% of property explored in detail
- Well understood targets
- 20 M Ag historic production
- Region with world-class projects
- Catalysts for higher valuation
- Northwestern BC region capturing new interest
The Way Forward – Targeted Exploration Programs
Validation and expansion of historical resource estimates
Identification of new Eskay type deposits:
- four targets
- Mineralization zones of 5-20m true widths
- Potential for high grade silver at depth
- Focus on Wolf and Torbrit zone
- New deposit identification:
- Largest alteration trend in district: 5km strike length on Property
- Potential for gold-silver VMS at depth beneath intense Red Point alteration zone.
The technical information in this website has been approved by Robert van Egmond, P.Geo., Chief Geologist of Dolly Varden and a Qualified Person.
The geology underlying the Dolly Varden property consists of volcano-sedimentary rocks belonging mostly to the lower and middle Jurassic Hazelton Group. These include intermediate volcanic and volcaniclastic rocks of the Betty Creek Formation and bimodal volcanic and sedimentary rocks of the Salmon River Formation.
The principal silver-base metal deposits of the Kitsault River valley have been interpreted as vein mineralization by early workers. Devlin (1986) reinterpreted the main deposits to be volcanic exhalative in origin. Deposits of this type are formed as sub-aqueous hot-spring type deposits on the seafloor, as products of hydrothermal solutions that have vented from sub-seafloor fracture and fault systems. Furthermore, the silver deposits of the upper Kitsault valley are mapped with important geological similarities to the Eskay Creek deposit, providing an analog for exploration on the Property.
The most prominent mineralized zone on the Property is an aerially extensive horizon of chemical sediment (“exhalative”) mineralization, known as the Dolly Varden-Torbrit Horizon (the “DVTH”) that extends from the Dolly Varden mine, on the west, passing though the North Star underground workings and continuing into the Torbrit mine, on the east. The DVTH exhalative body forms an almost continuous sheet, ranging in true thickness from 3 to 38 m, which extends from the Dolly Varden West zone to Moose-Lamb. Syn-depositional as well as post-dispositional faults have created a number of basins that divide the DVTH into offset blocks.
Separate from the DVTH body, the Red Point zone (on the western fringe of the upper Kitsault Valley) and the Wolf (on the eastern side of the valley) each have geological similarities to the targeted hydrothermal vein and sub-aqueous hot spring geology but are interpreted to share a position higher in the volcanic stratigraphy than the DVT horizon.
The Dolly Varden Mines properties comprise 8,800 hectares (88 km2) located in the Stewart Complex, which is host to both base and precious metal deposits, including the prolific Eskay Creek Mine. Over 220 M oz Ag and over 7 M oz Au has been produced by the Hazelton Group Arc Assemblage. High sulphidation VMS occurs in the youngest hazelton group rocks. The property hosts four historically active mines, with unexplored sectors.
The Dolly Varden Mines are a rich part of British Columbia’s mining history. In 1910 the Dolly Varden Mine was discovered by four prospectors of Scandinavian descent. The name ‘Dolly Varden’ hails from a heroine of Dickens’ novel, “Barnaby Rudge”, as foretold in a dream to a relative of one of the discoverers. The dream was indeed gilded with a silver lining.
The Dolly Varden Mine properties have produced assays of ore as high as 2200 ounces (over 72 kilograms) of silver per ton. The mines have historic production of 20 M oz Ag.
However, the initial discoverers were not to profit from their hard earned discovery. The Dolly Varden properties were sold to ambitious Chicago financiers in 1915. The mines’ new owners undertook to build a railway. Taylor Engineering Company was contracted to build the ‘Dolly Varden Mines Railway’; the last narrow guage railway built in B.C. The railway ran for just 16 miles, enabling the mining company to transport equipment and supplies to the mine site. It also facilitated the transport of the rich ore to the tidewater in Alice Arm for shipping to the smelter.
In 1918 differences arose between Dolly Varden Mines and the Taylor Engineering Company, resulting in the bankruptcy of the Taylor Company. A decision was reached by the Government of B.C., with the mine properties being turned over to Taylor. The previous owners were reimbursed for their investment in the Dolly Varden Mines.
In 1919, the newly established Taylor Mining Company took over both the Dolly Varden Mine and the railroad. The Torbrit deposit was located and explored while the neighbouring Dolly Varden mine was in production. Dolly Varden produced 1.305 million ounces silver from 36,000 tons at an average grade of 35.66 oz/ton silver (1,109 g/t Ag) from 1919 to 1921 (Herbert Hoover financed the operation prior to becoming US President).
Taylor lost control of the property in 1922 due to market conditions. In 1920, silver had dropped to less than $1.00 per ounce. The high costs associated with bringing the mine into production forced Taylor to forfeit title to the properties to George Wingfield’s interests. Goldfield Consolidated Mines Company took control in 1922, and reorganized into Northern Mining Properties, Limited, later renamed Dolly Varden Properties, Limited.
From 1923 to 1927 the Dolly Varden Mines Railway was utilized for logging operations. In 1929 the properties were optioned to Britannia Mining and Smelting Company, who conducted some development work, which was halted when the Great Depression hit. In the mid-1940s, the railway was replaced by a road. Subsequently, Torbrit Silver Mines Limited bought the property in 1946 and built and operated a 350 tonne-per day, hydroelectric-powered mill and flotation concentrator plant. The claims were later acquired by Victor Spence and associates and held by his interests until the 1950s. Torbrit Mine produced 18,706,847 million ounces of silver and 10.8 million pounds of lead from 1949-1959, from 1,377,632 tons at an average grade of 13.58 oz/ton Ag (466.3 g/t Ag) and 0.38% lead.
The Dolly Varden mine produced a small tonnage of high-grade silver ore that was direct shipped without beneficiation to base metal smelters, mainly to the nearby Granby Mines Anyox Copper smelter. The other deposit in the area to see production was the Torbrit, which comprises one of the potential deposits on the properties today. Production was in the form of a high-grade silver-lead concentrate and silver bullion.Taken together, about 20 million ounces of silver were produced from the mines on the Dolly Varden property, between 1919 and 1959.
Many of the significant properties in the upper Kitsault were assembled by Dolly Varden Mines Ltd., which was incorporated in 1960. Successive ownership changed ended in 1976, when Dolly Varden Mines Ltd. was put up for sale, and purchased by Dolly Varden Resources Limited. Subsequently, the company was amalgamated with three other companies holding land in the upper Kitsault valley under the name of Dolly Varden Minerals Inc. in 1979. From 1980 thru 1985 Dolly Varden Minerals, Inc. led by Fred Christianson, acquired and held title to the Dolly Varden Mines and later named Dolly Varden Resources. In 2011, Dolly Varden Silver Ltd. acquired Dolly Varden property from a private company. The Company went public under the name Dolly Varden Silver Corporation in 2012.
Geological work commissioned in the period 1979 to 1990 established the common geological characteristics of the major silver deposits and occurrences in the upper Kitsault valley. The rock formations and the style of mineralization and alteration on the Dolly Varden property share strong similarities to the Eskay Creek deposit, which is an exceptionally prolific gold and silver rich deposit, located 100 km north of the Dolly Varden property.
The property hosts two past producing deposits with production of 20 million ounces of Silver. The Dolly Varden Mine produced 1.5 million ounces at an average grade of 35.7 ounces per ton in the early 1920’s, and the Torbrit mine which produced 18.5 million ounces of silver at an average recovered grade of 13.58 ounces per ton from 1949 to 1959.
SOURCES OF HISTORICAL INFORMATION
Dolly Varden Mine: Skerl (1964) and Mann (1974) Dolly Varden Mine staff. Remaining resource blocks are in proximity to mined out stopes and downplunge extensions of mined out areas.
North Star Mine: Thompson & Pearson (1981) Derry Michener & Booth. Minimum mining width of 5 ft. No prior mining.
Torbrit Mine: Leigh & Thompson (1983) Derry Michener & Booth. Comprised of 18 zones. Most zones are in the hanging wall of the glory hole and mined out stopes of the 1959 operation.
Wolf No. 1 Zone: Thompson & Pearson (1981) Derry Michener & Booth. No prior mining. Tested by two levels of underground adits.
Wolf No. 2 Zone: Thompson & Pearson (1981) Derry Michener & Booth. No prior mining. Tested by three levels of underground adits.
Wolf No. 3 Zone: Thompson & Pearson (1981) Derry Michener & Booth. No prior mining.
Dolly Varden Silver Corporation 2011 through 2013
For the first several years of Dolly Varden Silver’s ownership of the property, field work focused on understanding the historic mines and testing mineralization within and adjacent to them. In 2011 the Company drilled 4,607 meters in 21 core holes at the Wolf Deposit, gaining assay highlights of 595 g/t silver over 15.2 meters in an epithermal vein and 384 g/t silver over 5.45 meters in a VMS layer. 2012’s drilling targeted the Dolly Varden mine, with underground rehabilitation, sampling and surveying plus 1,603 meters of drilling. Assay highlights from the Dolly Varden mine were 5.3 meters grading 536 g/t silver. Work in 2013 focused on the historic Torbrit mine with underground rehabilitation, surveying and sampling, in addition to 3,064 meters of drilling in 14 holes. Nearly all holes at Torbrit intersected significant VMS mineralization ranging in thickness from 9.3 meters to 89.1 meters. One assay highlight was 17.1 meters grading 509 g/t silver.
Exploration guidelines on the Property target an Eskay Creek type deposit that is a striking example of a class of high-sulphidation VMS deposits that form near sub-aqueous hot-spring vents where base and precious metal-rich hydrothermal fluids exhale onto the seafloor under shallow depths of seawater. At the Eskay Creek deposit, stratiform (bedded) layers of precious metal-rich chemical sediments and massive sulphides accumulate near vent areas and become the source for clastic sulphide debris in adjacent areas. The bedrock in the vent areas are underlain by precious metal rich feeder veins, stockwork veins and strong alteration.
The above diagrams (drawn at the same scale) show the size comparison of the key stratigraphic units and associated footwall alteration – feeder system as mapped at the Eskay Creek Deposit to the same stratigraphy and same style of alteration that has been mapped on the Dolly Varden Property.
Eskay Creek Exploration Model
A Schematic diagram, modified from Hannington, 1996, demonstrates the geological and spatial characteristics of the Precious Metal Rich VMS deposits with the key features as mapped at Dolly shown on the model. The DVT Exhalite which hosts the Silver deposits at Dolly Varden – North Star – Torbrit are correlated with the Barite-Silica Cap, and the Redpoint Feeder Zone correlates with the footwall stockwork alteration feeder zone.
Updated Mineral Resources Estimate – May 8th, 2019
*Mineral Resources are not Mineral Reserves. Mineral resources which are not mineral reserves do not have demonstrated economic viability. There has been insufficient exploration to define the inferred resource as an indicated or measured mineral resource, and it is uncertain if further exploration will result in upgrading the resource to a measured resource category. There is no guarantee that any part of the mineral resource discussed herein will be converted into a mineral reserve in the future.
**A 150 g/t silver lower cut-off was chosen to reflect conceptual underground mining and processing cut-off grade.
***Contained ounces may not add due to rounding.
****The resource estimation work reported herein was completed by Mr. Steven Nicholls, BASc., MAIG, with APEX Geoscience Ltd. (“APEX”) under the direct supervision of Mr. Andrew J. Turner, P.Geol., also with APEX. Both are independent geological consultants and Qualified Persons as defined by National Instrument 43-101.
*****An updated Technical Report, consistent with National Instrument 43-101, will be filed on www.sedar.ca within 45 days.