Dolly Varden Silver: 2013 Drilling Program Shows High-Grade Silver Mineralization Occurs at Multiple Stratigraphic Horizons at Torbrit Mine
VANCOUVER, BRITISH COLUMBIA–(Marketwired – Nov. 25, 2013) – Dolly Varden Silver Corporation (TSX VENTURE:DV)(OTCBB:DOLLF) (the “Company” or “Dolly Varden“), on November 8th, released the final assay results for its 2013 drill program (14 holes for 3,063m) over the historic Torbrit mine at the 8,800 hectare Dolly Varden property (the “Property”), in Northwestern BC. In the 1950s, the Torbrit mine produced in excess of 576 tonnes (18.5 million troy ounces) of silver at an average recovered grade of 466 g/t Ag (13.6 oz. /ton Ag).
Paul McGuigan, P.Geo., Vice President of Exploration, comments on the Torbrit mine exploration:
“Ongoing interpretation of Dolly Varden’s recent drill results indicates that the DVT exhalite horizon is comprised of at least two mineralized horizons and that most of the historic production at the Torbrit “Main Zone” was sourced from the lowermost horizon. The 2013 exploration has resulted in the discovery of a separate mineralized horizon, stratigraphically above the historically mined areas. This upper horizon (the Torbrit “Upper Zone”) is comprised of mixed stockwork, VMS & exhalite mineralization. Drill intersections from the “Upper Zone” contain similar silver grades and thicknesses to the past production from the lower horizon. Furthermore, the very highest grade intersections are interpreted to cut the Torbrit Main Zone and Upper Zone at a high angle, and are interpreted as discrete panels of the highest grade silver.”
Please follow link to see plan and sections of this summer’s drill program.
FAVOURABLE CORRELATION WITH ESKAY CREEK SETTING
Company integration of all the geological, geochemical, geophysical and structural information confirms that the structural framework, and mineralization styles of the Dolly Varden deposits favorably correlate with the setting of the Eskay Creek Au-Ag VMS deposit. This compilation demonstrates that precious-metal-rich exhalite and VMS mineralization occurs within two important stratigraphic units on the Property, each unit containing multiple drilling targets for a 2014 program:
- DVT Horizon: at the base of the Eskay rift assemblage, where the newly understood Torbrit geology makes the base of the Eskay rift prospective for similar silver-rich mineral deposits at other locales on the Property, both adjacent and stacked, within and above the DVT horizon, and
- Eskay analogous – Contact Horizon: lying about 300 m above the DVT Horizon, where a major regional contact occurs between felsic volcanics and overlying sediments. Current and historical sampling and analyses show a strong potential for an Eskay Creek type Au-rich VMS.
The Company’s conclusions are supported by recent geological publications, including observation by Dunne & Pinsent (2002), BC Geological Survey Branch that stated “the Dolly Varden deposits may be the silver-rich equivalents of the precious metal-rich Eskay Creek deposit”. The very high grade Eskay Creek deposit that is located 120 kilometers to the northwest of Dolly Varden, produced 3.6 million ounces of gold and 180 million ounces of silver between 1995 and 2007.
A Schematic Time stratigraphic diagram, illustrating the relationship between the prospective horizons, is available on the Company website.
MULTIPLE STAGES OF SILVER MINERALIZATION COMPOSE THE TORBRIT DEPOSIT
As previously disclosed by the Company, a NW-striking, normal fault (the “Northwest Fault” – a growth fault) disrupted the DVT horizon during its time of formation, placing the DVT horizon up to 150m lower on its east side, over time. Importantly:
- The steeply east-dipping Northwest Fault served as a linear feeder for the upwelling of multiple stages of mineralizing hydrothermal fluids and for venting of fluids onto the seafloor of the DVT horizon. Underground structural geological mapping in the Torbrit documented faulting and mineralization within a key sub-basin that defines the highest widths and grades within the Torbrit mine and DVT Horizon.
- 2013 Torbrit underground geological mapping and sampling shows the silver mineralization was introduced in multiple stages. Mid- and late-stage mineralization introduce much greater concentrations of native silver into the Torbrit structure, and onto the sea-floor, in successively repeating and overlapping events, adding significantly to the total silver grade.
- Drilling in 2013 has begun to define the distribution of these overlapping silver mineralizing stages. The veins, breccia and VMS of the later stages are mappable and, in 2013 drilling, yield core intervals of up to 17m of moderate- to high-grade silver.
DISCUSSION OF SIGNIFICANT NEW INTERPRETATIONS:
The Company continued with a balanced mineral exploration effort on the Property in 2013. Field crews mapped and sampled mineral showings and key lithologies across the entire Iskut River formation on the Property. Iskut River formation is the current Geological Survey of Canada nomenclature in the region for volcanic and sedimentary formations that fill the multiple sub-basins of the Eskay Rift. Combined with the new mapping at the Torbrit and the Dolly Varden mines, the following very significant conclusions can be supported:
- DVT Horizon exhalite is located at the base of the volcanic units of the Iskut River formation.
- An upper horizon, analogous to the Eskay – Contact Horizon geology is prospective for Eskay-type Au-Ag VMS, and lies about 300 to 400m above the DVT, at a major regional contact between felsic volcanics and overlying sediments. The Contact Horizon remains largely untested.
- At the Dolly Varden mine, high-grade silver mineralization occurs in veins and stockworks that cut the basal volcanic unit and crosses almost the entire vertical range of the unit.
- At the Wolf, and now Torbrit, fault and graben-related silver-rich veins and stockworks are feeders for Eskay-type VMS and exhalite. In the case of Wolf, the “Contact Horizon” with sediments is mineralized by a local vent that overlies the linear vein and stockwork system. At Torbrit, our 2013 diamond drilling shows that the VMS-exhalite is vented and deposited on the seafloor next to an active fault and graben system. Several “stacked” stratabound VMS and exhalite lenses occur over a range of up to 250m vertically, adjacent to the fault system.
QA/QC and Qualified Person (QP) Pursuant to Canadian National Instrument 43-101
Quality control procedures consisted of insertion of blanks, duplicates and standards. All analytical results reported herein have passed the Company’s ongoing QA/QC review. All drill core and rock samples for analysis were subject to metallic screen assay procedures, employing a large, one kilogram, pulverized sub-sample of each interval.
Paul McGuigan, P. Geo., Vice President – Exploration of Dolly Varden Silver Corp., who serves as a Qualified Person under National Instrument 43-101, supervised and approves the preparation of the scientific and technical information disclosed in this news release. Information regarding data verification, surveys and investigations, quality assurance program and quality control measures and a summary of analytical and testing procedures are provided on the Company’s website.
Certain of the statements and information in this press release constitute “forward-looking statements” or “forward-looking information”. Any statements or information that express or involve discussions with respect to predictions, expectations, beliefs, plans, projections, objectives, assumptions or future events or performance (often, but not always, using words or phrases such as “expects”, “anticipates”, “believes”, “plans”, “estimates”, “intends”, “targets”, “goals”, “forecasts”, “objectives”, “potential” or variations thereof or stating that certain actions, events or results “may”, “could”, “would”, “might” or “will” be taken, occur or be achieved, or the negative of any of these terms and similar expressions) are not statements of historical fact and may be forward-looking statements or information. Forward looking statements or information relates to, among other things, the Company’s exploration plans for the Dolly Varden silver property and the Company’s expectations with respect to the geological features of mineralization on its properties.
Forward-looking statements or information are subject to a variety of known and unknown risks, uncertainties and other factors that could cause actual events or results to differ from those reflected in the forward-looking statements or information, including, without limitation, the speculative nature of exploration and the stages of the Company’s properties; and that expected geological, mineral or metallurgical expectations or models may not prove to be correct. This list is not exhaustive of the factors that may affect any of the Company’s forward-looking statements or information. Although the Company has attempted to identify important factors that could cause actual results to differ materially, there may be other factors that cause results not to be as anticipated, estimated, described or intended. Accordingly, readers should not place undue reliance on forward-looking statements or information.
The Company’s forward-looking statements and information are based on the assumptions, beliefs, expectations and opinions of management as of the date of this press release, and other than as required by applicable securities laws, the Company does not assume any obligation to update forward-looking statements and information if circumstances or management’s assumptions, beliefs, expectations or opinions should change, or changes in any other events affecting such statements or information. For the reasons set forth above, investors should not place undue reliance on forward-looking statements and information.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release.
Vanguard Shareholder Solutions
Martin Gagel, MBA, CFA Vice President
604-608-0824 or 877-608-0829
Dolly Varden Silver Corporation
Ron Nichols, P. Eng. CEO and President
1-778-383-3083 or Toll Free: 1-855-381-3530