million tonnes averaging 18.4% Zn, 8.6% Pb, 1.6% Cu, 112 g/t Ag & 1.7 g/t Au. Lucky Strike was the largest of five ore bodies comprising the Buchans mine that ultimately processed a total of 16.2 million tonnes averaging 14.51% Zn, 1.33% Cu, 7.56% Pb, 126 g/t Ag & 1.37 g/t Au before it was closed in 1984.
Minco's 2015 programme was undertaken to follow up of favourable results from drilling in 2014 and tested several mineralized stratigraphic horizons to explore for new high-grade massive sulphide deposits to depths of 300 metres. Highlights included the intersection of widespread ore clast mineralization comprised of massive sulphide fragments hosted by volcanic breccias within a deeper stratigraphic horizon known as the "Ore Clast" horizon. This horizon is located below the Lucky Strike mine horizon and the lesser explored Engine House horizon.
All eight 2015 Minco holes designed to test the Ore Clast horizon intersected mineralized felsic volcanic breccia ranging from 1 to 23 metres in thickness, and containing massive sulphide and sulphide-rich clasts measuring up to 15 centimetres in diameter. Intercepts include 0.5 metres averaging 13.32% combined base metals (i.e., Cu%+Pb%+Zn%) as 1.80% Cu, 5.20% Pb, 6.32% Zn, 53.3 g/t Ag, and 0.18 g/t Au in hole H-15-3493, as well as 1.0 metre averaging 6.16% combined base metals as 0.35% Cu, 1.72% Pb, 4.10% Zn, 63.4 g/t Ag, and 0.27 g/t Au in hole H-15-3497.
In light of these positive results, Minco expanded its programme of re-logging historic drill holes to assess potential for new high-grade discoveries within the Ore Clast horizon, below depths of previous mining. During 2015, Minco re- logged 156 historic surface and underground drill holes (13,418 m) southwest of the former Lucky Strike mine. This re- logging work focused in on a small high-grade massive sulphide deposit known as the West Orebody deposit, with reported base metal grades similar to Lucky Strike.
The West Orebody deposit was discovered by Asarco in 1940 at a depth of 300 m and consisted of a cluster of small but high-grade massive sulphide lenses. This deposit was mined during the mid-1940's and is believed to have produced less than 100,000 tonnes of ore. While production records and other details are scanty, the deposit has not been a focus of exploration since the 1940s, when the deposit was last drilled by short underground holes and a few widely-spaced surface holes and underground drilling tended not to test the lateral extents of the ore horizon more than 50 metres beyond the developed orebody.
Re-logging and reinterpretation of archived drill cores by Minco now suggests the West Orebody mineralization occurs near the intersection of the Lucky Strike Horizon and the stratigraphically deeper, Ore Clast Horizon. It is further interpreted that the Ore Clast horizon is in part a structural feature or rift fault that was active during formation of the Lucky Strike and West Orebody deposits, and may have acted as a control structure or mineralized trend for high-grade massive sulphides. Minco has planned a five hole 2,000 metres drilling program to explore the West Orebody deposit. The Company is seeking CDN$100,000 in grants from the government's Junior Company Exploration Assistance program, a government-funded exploration incentive program that provides matching funds of up to CDN$100,000 to support mineral exploration programs in Newfoundland.
The Company's ongoing re-logging program at Buchans is currently assessing potential targets in the vicinity of the West Orebody and Lucky Strike deposits for discovery of additional high-grade ore near the Company's Lundberg deposit. This program is expected to dominate field activities in Buchans for the remainder of 2016 and is being undertaken with a goal of discovering additional high-grade ore that could contribute to the development of a combined open pit and underground mining operation at Lundberg.
Minco's Lundberg deposit is the most advanced undeveloped deposit in the district and consists of a large lower grade resource being evaluated for open pit mine development. The deposit hosts Indicated resources of 23. 4 million tonnes grading 1.41% Zn, 0.60% Pb, 0.35% Cu, 5.31 g/t Ag and 0.07 g/t Au, and Inferred resources of 4.3 million tonnes averaging 1.29% Zn, 0.54% Pb, 0.27% Cu, 4.47 g/t Ag and 0.08 g/t Au (see Minco press release dated March 4, 2013 for more complete disclosure).
METALLURGICAL STUDIES - CENTRAL NEWFOUNDLAND BASE METAL PROJECTS
In December 2015, through its wholly owned subsidiary Buchans Minerals Corporation ("Buchans Minerals), Minco entered into a collaboration agreement with Canadian Zinc Corporation (TSX:CZN) ("Canadian Zinc") to undertake a research programme to complete physical and metallurgical bench scale studies on seven volcanogenic massive sulphide ("VMS") deposits located in central Newfoundland and to share research data on their respective central Newfoundland Cu-Pb-Zn-Ag-Ag deposits. The agreement covers seven VMS deposits located in central Newfoundland, including three deposits held by Buchans Minerals (Bobbys Pond-100% Minco, Daniels Pond-100% Minco and Tulks Hill-49% Minco) and four deposits held by Canadian Zinc (Lemarchant, Boomerang-Domino, Tulks East, and Long Lake).
Minco's Daniels Pond hosts an Indicated Mineral Resource estimate of 1.16 million tonnes grading 4.44% zinc, 2.12% lead, 0.31% copper, 87.79 g/t silver and 0.60 g/t gold, as well as an additional Inferred resource totaling 445,000 tonnes grading 3.88% Zn, 1.74% Pb, 0.27% Cu, 81.63 g/t Ag and 0.52 g/t Au (see Buchans Minerals press release dated March 13, 2008 for full disclosure). Bobbys Pond hosts an Indicated Mineral Resource of 1.10 million tonnes grading 4.61% zinc, 0.44% lead, 0.86% copper, 16.6 g/t silver and 0.2 g/t gold plus an additional Inferred Mineral Resource of 1.18 million tonnes grading 3.75% zinc, 0.27% lead, 0.95% copper, 10.95 g/t silver and 0.06 g/t gold (RPA, July 2008; see Minco press release dated July 31, 2013 for complete disclosure). The 49% Minco-owned Tulks Hill deposit (51% Prominex Resource Corp) hosts Indicated Mineral Resources totaling 431,000 tonnes averaging 3.97% zinc, 1.61% lead, 0.89% copper, 35.09 g/t silver and 1.17 g/t gold (see Buchans Minerals press release dated July 24, 2008 for complete disclosure).
The total cost of the research project is estimated at $735,000, with Buchans Minerals and Canadian Zinc each contributing up to $100,000. The Research & Development Corporation of Newfoundland and Labrador is providing funding of $535,000 for the research project through the GeoEXPLORE Industry-led R & D Technology Development and Demonstration Program.
The objective of the program is to evaluate the technical and economic viability of developing some combination of these deposits by utilizing a central milling facility. The evaluation is focused on metallurgical aspects of the deposits to determine if the deposits benefit from pre-concentration before trucking and milling, simultaneously or sequentially, through a central mill.
In December of 2015, Minco completed a seven (7) hole, 781 metre, drilling programme at its Daniels Pond and Bobbys Pond deposits to collect fresh rock samples for metallurgical testing including grindability characterization, acid generation assessment, bench scale flotation testing and bench scale Dense Media Separation ("DMS") pre- concentration testing. Minco also collected a smaller representative sample from the Tulks Hill deposit from archived drill core for bench scale DMS testing.
To date the program has completed DMS tests on all the deposits and is now in the process of completing flotation tests to determine the estimated metal recoveries. Thibault & Associates Inc. ("Thibault"), an independent process chemical engineering firm, was engaged to carry out the bench scale studies to be followed by the development of a process simulation and order of magnitude cost assessment model on the deposits. Twelve DMS samples and five metallurgical samples were submitted to Thibault for testing. The samples were selected to represent as closely as possible the characteristics of the mineralization making up each resource. Highlights to date of the DMS and metallurgical testing include:
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Preconcentration of the ore by DMS (prior to flotation) was determined to be technically viable for semi-massive and stringer sulphide samples from the Boomerang-Domino, Lemarchant, Long Lake, Bobbys Pond and Daniels Pond deposits.
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Initial flotation tests indicate the deposits are amenable to a common flotation flowsheet with the sequential Cu-Pb- Zn flotation flowsheet providing the best overall performance for all four deposits tested. Further development of the sequential flotation by bench scale testing is in progress.
DMS Testing (completed)
The bench scale DMS testing was designed to assess the amenability of mineralized samples from the deposits to physical upgrading (pre-concentration) at each site as a potential means of reducing transportation costs from mine site to the milling facility and to maximize head grade to reduce downstream processing costs.
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Six samples identified as semi-massive sulphide or footwall stringer mineralization achieved a technically viable grade and recovery of base metals using bench scale separation tests.
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The remaining six samples identified as massive sulphide and/or barite mineralization were not significantly improved through DMS bench scale tests.