The Knife Lake Project is interpreted to be a remobilized VMS deposit. The stratabound mineralized zone is approximately 15 m thick and contains copper, silver, zinc and cobalt mineralization which dips 30° to 45° eastward over a strike-length of 4,500 m, with an average horizontal width of approximately 300 m. Over 400 diamond drill-holes have been completed in and around the current property boundaries, with much of the drill core stored under cover and in very good condition.
1968: Knife Lake mineralization discovered by Straus Exploration 130km NNW of Flin Flon
1968-1972: Extensive drilling completed totaling 87 holes (8,484m), mining lease established
1989: CopperQuest formed, completes extensive geophysics, 24 holes (1,829m)
1996: Leader Mining acquires leases from CopperQuest and completes positive preliminary metallurgical work
1996-1998: Leader Mining completes delineation drilling: 317 holes completed (30,866m)
1997: Leader publishes non NI 43-101 geological reserves of the Knife Lake Deposit, reporting a drill-indicated resource of 20.3 million tonnes grading 0.6% Cu, 0.1 g/t Au, 3.0 g/t Ag, 0.06% Co and 0.11% Zn
1999-2002: Metal prices collapse and exploration budgets are cut during bear mining market
2003: Leader Mining issued Cease Trade Order which remained in place for over 3 years
2009: Ursa Major International acquires Knife Lake lease and surrounding claims
2010-2014: Ursa Major International name change to Minnova Gold and focuses on gold projects; very little exploration carried out on Knife Lake Project
2017: Knife Lake mining lease lapses and area becomes open for staking
2018: Eagle Plains, a prospect generator, stakes area of expired lease and acquires additional tenure as well as access to existing drill-core; seeks to farm out property as part of business model
2018-2019: Eagle Plains and Rockridge enter into option to acquire 100% interest of large, 85,197 ha, property package and TerraLogic contracted to carry out the exploration programs going forward
Knife Lake Deposit Map:
The deposit is hosted by felsic to intermediate volcanic and volcaniclastic rocks which have been metamorphosed to upper amphibolite facies. The deposit is typical of VMS mineralogy which has been significantly modified and partially remobilized during the emplacement of granitic rocks. The mineralization straddles the boundary between two rock units and occurs on both limbs of an overturned fold.
The Knife Lake area saw extensive exploration from the late 1960’s to the 1990’s with the last documented work program completed in 2001. Drilling has outlined a series of stratabound mineralized lenses which are controlled by complex geological structures. In the copper mineralized zone, significant thickening of the mineralization occurs near the central portion of the deposit. Sulphides and rare native copper are visible in outcrop. Massive sulphides consist of 25% to 60% pyrrhotite and 0.2% to 10% chalcopyrite mineralization. Pyrite is present as irregular disseminations and masses. Locally, up to 8% sphalerite (zinc mineralization) is present.
|Table 1- Significant Drill Intercepts-Knife Lake Project*|
|Hole ID||Width (m)||From (m)||To (m)||Cu (%)||Au (ppb)||Ag (ppm)||Co (ppm)||Zn (ppm)|
* Intercepts in the above table refer to an actual drilled thickness in metres and may not represent the true thickness of the intercept
The first documented work in the Knife Lake showing area occurred between 1969-1973, consisting of ground and airborne geophysical surveys and extensive soil geochemical sampling. The discovery drill-hole, collared in September 1969, returned 2.37% Cu over 4.48 m from 19.96-24.44 m, including 3.5% Cu over 2.5 m from 20.27-22.77 m. A total of 96 diamond drill holes (8,232 m) were completed between 1969-1971 and in 1973 Straus Exploration announced a maiden resource on the Knife Lake Deposit.
Hudson Bay Exploration and Development Company Ltd. later carried out a regional Airborne EM geophysical survey in the Knife Lake – Scimitar Lake area followed up by geological mapping, prospecting, ground geophysics, and diamond drilling. The property was subsequently optioned to Copperquest Incorporated in 1989, who carried out further geophysical and geochemical surveys and optioned the property to Leader Mining International in 1996. Between 1996 and 2001, Leader flew various airborne geophysical surveys in the area, including electromagnetic (“EM”), magnetic, and gravity surveys. This was followed up with stripping and trenching of the outcropping deposit area. Ground TEM, magnetic, ground IP/Resistivity and VLF-EM surveys were completed over and adjacent to the main deposit area.
Between 1996 and 1998, Leader completed 315 diamond drill holes, outlining a broad zone of mineralization occurring at less than 100 meters depth (AF 63M-0006, Report 10). Late in 1998, Leader published a historical estimate for the deposit, reporting a drill-indicated resource of 20.3 million tonnes grading 0.6% Cu, 0.1 g/t Au, 3.0 g/t Ag, 0.06% Co and 0.11% Zn. Within the historical estimate, there is a higher grade zone containing 11.0 million tonnes grading 0.95% Cu. (SMDI 0406). Rockridge Resources’ management considers these estimates to be historical in nature and cautions that a Qualified Person has not done sufficient work to classify the historical estimates as current mineral resources or mineral reserves in accordance with National Instrument 43-101. These estimates do not comply with current definitions prescribed by National Instrument 43-101 or the Canadian Institute of Mining, and are disclosed only as indications of the presence of mineralization and are considered a target estimate to help guide additional work. The historical models and data sets used to prepare these historical estimates are not available to Rockridge, nor are any more recent resource estimates or drill information on the Property.
In 1997, Leader International shipped a 2.4 tonne bulk sample of mineralized material excavated from the surface outcrop of the Knife Lake deposit to Lakefield Research Limited for metallurgical test-work. Lakefield concluded that the copper metallurgy was straightforward. Following a simple flowsheet, greater than 90% copper recovery was achieved at a concentrate grade of 28% Cu. Gold recovery in the copper concentrate was 80%. The cobalt recovery in the copper cleaner concentrate was 13%, with 28% of the cobalt present in cleaner tailing products. Another 48% of the cobalt was present in the sulphide concentrate.
A 357kV powerline has recently been completed to within 16 km of the Knife Lake Deposit area, greatly enhancing the project’s infrastructure.
The Company is planning for diamond drilling programs in 2019 with an initial drill program underway. Drill permits are in place and further details of the drill program are forthcoming.
Under the terms of the Agreement, which is subject to TSX Venture Exchange (the “Exchange”) approval, Rockridge may acquire a 100% interest in the Knife Lake Project by making cash payments to Eagle Plains Resources totaling CDN $150,000, issue up to 5,250,000 common shares of Rockridge, and incur exploration expenditures of up to CDN $3,250,000, over a four year period as follows: