PALMER COPPER-ZINC-SILVER-GOLD PROJECT
Defining high-grade, low-capex type targets within
a multi-deposit, district-scale environment.
High Grade - Accessible - Growing
- Advanced stage exploration project in Southeast Alaska with road access and located only 60 km from a deep-sea port.
- Hosts a NI 43-101 compliant 4.677 million tonne indicated (11.67 ZnEq. or 3.84% CuEq.) and 5.338 million tonne inferred (9.90% ZnEq. or 3.26% CuEq.) resource estimate (detailed grades tabulated below; see news release dated September 27, 2018 ) - open to expansion
- Joint Venture partnership between Constantine (51%) and Dowa Metals & Mining Co., Ltd. (49%) - Constantine as operator.
- Large property with numerous underexplored base metal prospects that define more than 15 kilometers of favorable mineral trends - hallmarks of a major (+30 Mt) massive sulphide system and opportunity for discovery of multiple deposits.
- Hosted by the same Late Triassic volcanogenic massive sulphide (VMS) belt as the high-grade producing Greens Creek mine, and the giant 298 Mt Windy Craggy copper deposit - a world class environment.
Resource Estimate - All Zones Open To Expansion
An updated mineral resource estimate has been initiated that will incorporate drilling and analytical data acquired since the resource was last updated early 2015. In addition to significant new South Wall drill results (e.g. 2.5% Copper and 7.4% Zinc over 45.4 meters in hole CMR17-82) the resource estimation will also include evaluation of the new AG Zone discovery. Results of metallurgical test work currently underway also be incorporated in the estimation, including assessing the viability of barite as a marketable commodity, and potential optimization of copper and zinc recoveries. Upon completion of the updated resource, a Preliminary Economic Assessment (PEA) study will be initiated.
In September 2018, independent consultant James N. Gray of Advantage Geoservices Ltd. was commissioned to prepare an updated resource estimate for the RW and South Wall Zones of the Palmer project, in order to include all drilling completed to the end of 2017.The update represented the first Indicated Resource for Palmer, accounting for 47% of the total resource (4.677MT Indicated grading 11.67% ZnEq. or 3.84 CuEq & 5.338MT Inferred grading 9.90% ZnEq. or 3.26% CuEq.). This was the first resource to report barite mineralization for the Palmer deposit, highlighting the opportunity for barite to contribute value as an industrial mineral co-product. A separate maiden resource for the nearby AG Zone discovery has been scheduled for late 2018 to include recent drill results that have significantly expanded the extent of this new area of mineralization first identified in 2017.
The 2018 43-101 Technical Report is available here
- Steep geometry of thick, continuous zones of massive sulphide coupled with the potential to access by short lateral drifts at lower elevations makes for potential lower cost mining
- Very good response to conventional metallurgy, with high metal recoveries produced at moderate grind sizes. Initial locked cycle flotation tests yielded good quality, smeltable copper and zinc concentrates.
- The Company has completed preliminary environment baseline studies maintains annual monitoring programs.
2018 exploration and development plans include:
- 10,000 meters diamond drilling starting in June. Objectives of the drill program are:
- Systematically define and expand the South Wall & RW Zone resources
- Expand the AG Zone, a new silver-gold-zinc rich discovery made in 2017
- Test new regional prospects derived from historical sampling and supported by 2017 airborne EM-Mag survey
- Property-wide geological mapping and prospecting
- Updated mineral resource estimate
- Updated Cu/Zn metallurgical studies and preliminary scoping barite metallurgical program
- Initiation of preliminary economic assessment study
- Ongoing engineering and environmental studies and permitting
- Advance plans to initiate permitting underground exploration development
- Additional access road construction
- Ongoing community engagement and environmental management of our activities
Existing access road and laydown constructed in 2014, South Wall in distance.
Location And Property Information
The Palmer Property is located in the Alaska panhandle and lies less than two kilometres from the Haines Highway, which links the deep-sea port of Haines, Alaska, a terminal of the Alaska Marine Highway system, with British Columbia, Yukon, and the Alaska Highway. The Property consists of a contiguous block of land consisting of 340 federal unpatented lode mining claims, which cover an area of approximately 6765 acres (~2738 hectares or 27 km2) and 63 state mineral claims that cover an area of approximately 9200 acres (~3680 hectares or 37 km2).
In 2014, Constantine was the successful applicant in a competitive lease process for the 'Haines Block' offered by the Alaska Mental Health Trust Authority, a state corporation within Alaska (see news release dated September 9, 2014). The Trust owns the subsurface mineral estate of the Haines Block, and for a small subset of the block, located adjacent to the Palmer property, land is held fee simple for which the Trust owns both the surface and subsurface estate. The lease was finalized and signed with an effective date of September 1, 2014, thereby consolidating a district-scale property position totaling approximately 82,000 acres, inclusive of the Palmer state and federal claims.
- Excellent infrastructure including expanding hydro power capacity, road access, and port providing access to hungry Asian smelting markets
- Politically stable jurisdiction with established permitting process - active hard rock mines in the region include Greens Creek and Kensington
- Located in an area of active resource development; logging and placer mining within two kilometers of the Property
Geology And Expansion Potential
The Palmer Project is a volcanogenic massive sulphide (VMS) type deposit that is located within the same belt of rocks that is host to the Greens Creek and Windy Craggy VMS deposits - both widely recognized to be world class systems. For both grade and size, there is no better VMS belt to explore. As a deposit class, VMS are attractive for being polymetallic (multi-metal) and having high dollar value per tonne.
The Palmer project is located in the Alexander Terrane, with mineralization hosted within marine sedimentary and volcanic rocks of Triassic age. These rocks correlate with host rocks of the giant Windy Craggy deposit (297 million tonnes at 1.4% Cu, 0.07% Co, 0.2 g/t Au, and 3.8 g/t Ag), and the high-grade Greens Creek deposit with probable reserves of 8.24 million tons grading 12.1 opt Ag, 0.092 opt Au, 9.3% Zn and 3.5% Pb (Dec 2010) and an estimated global resource of 24.2 million tons grading 19.2 opt Ag, 0.15 opt Au, 13.9% Zn, and 5.1% Pb.
The numerous showings and prospects on the Palmer property occur along two mineralized trends over a combined strike length of at least 9 miles. Repetition of the principal mineralized horizons by folding is interpreted to account for the distribution of at least 25 separate base metal and/or barite occurrences) across the property. Recent work has established the existence of more than one stratigraphically stacked mineralized horizon.
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Notable prospect areas include Glacier Creek (South Wall and RW zones), Mount Henry Clay, Cap, Nunatak, Hanging Glacier, the Gullies, Boundary and Red Creek. The showings/occurrences are associated with interpreted exhalative horizons in a thick sequence of basalt flows with interbeds of sediments, andesite flows and tuffs and fragmental and massive rhyolites. Extensive pyrite-sericite schists and siliceous rocks provide a common link to the showings suggesting the presence of a very large extensive mineralized system.
The Glacier Creek prospect has received the most attention. Mineralization at Glacier Creek occurs on both limbs of a large-scale south-overturned anticline that is cored by a south-directed reverse fault with modest offset. Two major stratiform horizons, the RW and Main horizons, have been identified on the shallowly to moderately dipping upright limb of the anticline. Highlight drill intersections of the RW horizon include 3.79% copper and 7.24% zinc over 14.0 meters in hole CMR07-07, and 10.86% zinc, 0.13% lead, 0.23% copper, 0.13 g/t gold and 44.4 g/t silver over 5.12 meters in hole CMR06-01. Three separate, stratigraphically stacked zones (South Wall zones I, II, and III) have been identified on the steeply dipping to overturned limb of the anticline. Highlight intersections include drill hole CMR08-14 that contains an interval of 15.2 meters of 5.1% copper, 1.79% zinc, 0.29 g/t gold and 20.5 g/t silver within a larger interval of 46.4 meters of 2.92% copper and 2.98% zinc. Both the RW and South Wall zones are open down dip and along strike.
At the Mount Henry Clay (MHC) prospect, abundant high-grade baritic massive and semi-massive sulfide boulders occur near the limits of a perched or stranded glacier. The average grade of a large number of the boulders is: 19.3% zinc, 1% copper, 0.4% lead, 38.2 g/t silver, 0.22 g/t gold, and 20.6% barium. Although the source of the boulders has not been determined, the area remains attractive for discovery.
Silver-and barite-rich stratiform mineralization at the Cap prospect (134 g/t Ag over 23 m) remains virtually untested at depth and laterally, and other occurrences on the property have also yielded excellent precious-metal values (e.g., 11.84 oz/ton Ag and 0.092 oz/ton Au in a bulk sample of baritic semi-massive sulfide from Nunatak, and up to 198.9 g/t silver, 1.58 g/t gold, 14.1% zinc, 2.3% lead, and 0.36% copper from massive sulfide at the HG prospect).
Detailed geology and mineralization information for each of the prospects is available in the 2018 43-101 Technical Report
Base-metal sulfides and barite were first discovered in the vicinity of the RW and South Wall Zones (Glacier Creek prospect area) in 1969 by local prospector Merrill Palmer.
Palmer staked the discoveries and continued to prospect the area in subsequent years. In the early years following discovery, exploration focused on the economic potential of barite. Tests showed the baritic material to be suitable for production of drilling mud concentrates, although none of the prospects were developed. Many of the baritic units exposed in the area are highly oxidized and leached of sulphides, a feature of major exploration significance that was not fully appreciated until recently. It was drilling down dip of these surface showings beyond the influence of oxidation that led to Constantine’s RW and South Wall discovery intersections - 38 years after the original surface discovery.
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In 1979, Anaconda Copper Company drilled the first three diamond drillholes on the Property, totaling 801 m, in the Glacier Creek Prospect area. All holes failed to intersect the main mineralized barite-base metal horizons, although one hole (GC-2) did intersect the narrow, distal expression of South Wall Zone III.
It was not until the exploration successes at Windy Craggy and Greens Creek were realized in the early 1980s that the base metal potential at Palmer was fully understood. In 1983, high-grade massive sulphide boulders up to 1.8 m (6 ft) in diameter and grading up to 33% Zn and 2.5% Cu were discovered at the toe of a small ice sheet near Mount Henry Clay. Twenty-six samples of various boulders collected by the U.S. Bureau of Mines returned an average grade of 19.3% Zn, 1.0% Cu, 0.4% Pb, 38.2 g/t Ag, 0.22 g/t Au, and 20.6% Ba, and their discovery led to four successive drill programs (Bear Creek Mining (Kennecott) 1984 and 1985; Granges Exploration Inc 1989; and Rubicon Minerals Corporation 1999, with a total of thirteen holes and 2958 m of core being drilled. None of the programs were successful in locating the source of the boulders, and the prospect remains an attractive exploration target.
In the mid to late 1980’s Newmont Exploration Ltd. pursued the precious metal potential at the Palmer Property, with particular attention being given to the Cap and Nunatak prospects. At the Cap prospect, massive pyritic barite and baritic breccia was drilled in 1988 and 1998, with the best intercept of four holes being 134 g/t Ag over 23.2 m. At the Nunatak prospect, a 91 kg (200 lb) bulk sample divided into thirteen separate samples returned an arithmetic average grade of 11.84 oz/ton Ag and 0.092 oz/ton Au.
In the early 1990s, retreating ice exposed an outcrop of massive sulphide in the Glacier Creek prospect area that became known as the Little Jarvis occurrence. Chip samples by Kennecott from the Little Jarvis occurrence yield up to 13.0% Zn, 7.0% Cu, 0.02 oz/ton Au, and 7.0 oz/ton Ag over 4.6 m (15 ft), although chip sampling at the same locality by Rubicon Minerals Corp. in 1998 yielded somewhat lower grades: 10.8 % Zn, 0. 27% Cu, 0.17 ppm (0.005 oz/ton) Au, and 44.2 ppm (1.29 oz/ton) Ag over 3.05 m (10 ft). The interpretation that the Little Jarvis occurrence was correlative with the Upper Main occurrence on the other side of the mountain to the southeast, led to Rubicon Minerals’ drill hole discovery of the RW zone in 1999. Rubicon intersected semi-massive to massive sulphide in four holes ranging from 2.5 m to 6.3 m in width and established down dip continuity of more than 200 m; however, due to deteriorating market conditions at the time Rubicon did not follow up on their initial discovery.
Constantine Metal Resources Ltd. was formed in 2006 with the purpose of exploring the Palmer property. The first of three holes drilled by Constantine in 2006 intersected 5.12 m grading 10.86% zinc and 44.4 g/t silver, and demonstrated the presence of massive sulphide 300 m east of Rubicon’s initial RW zone discovery holes.
In late 2007, Constantine intersected high-grade copper and zinc mineralization over a width of 14 meters at the RW zone (CMR07-07). The drill was then moved over 400 meters to the east, where discovery hole CMR07-09 intersected 24.2 meters of massive sulphide at what is now referred to as the South Wall zone. In 2008, Constantine followed up on the initial South Wall discovery with hole CMR08-11, which intersected 46.85 meters of massive sulphide, followed by a second 23.2 meter massive sulphide zone, followed by a third 12.59 meter massive sulphide zone. The cumulative width of the three stratigraphically ‘stacked’ zones in this drill hole is 82.64 meters.