Case spodumene pegmatite swarm is located 80 km east of Cochrane and 100 km north of Kirkland Lake, NE Ontario. It is accessible year-round by road via the Translimit Road which connects Ontario and Quebec.
Case pegmatite swarm consists of five dykes exposed on surface (Breaks et al., 2006, OFR6195; MNDM assessment reports: 32E04SW2002, 2000; 32E04SW2003, 2001; 32E04SW2004, 2001; 2.47355, 2011):
- North Dyke – 12 m thick and > 100 m strike length
- Main Dyke (also known as Central Dyke) – 35 m thick and > 350 m strike length
- South Dyke – 10 m thick and > 250 m strike length
- East Dyke – 19 m wide and > 1200 m strike length
- Northeast Dyke – 10 m wide and > 75 m length
All of the known Case pegmatite dykes are open along strike, as the current strike length only represents surface exposure and doesn’t represent the total length of the pegmatite dykes. Thus there is potential to increase the strike length of each mineralized dyke.
The North, Main and South dykes are hosted by the Case granodiorite batholith and they strike at 60 to 70° and dip 40 to 60°. The East and Northeast Dykes are hosted by fine-grained biotite-garnet metasedimentary rocks. The East Dyke is steeply dipping and has a E-W strike. The Northeast Dyke has a shallow dip and trend in a northeast-southwest direction. The Northeast Dyke consists of northern and southern exposures and numerous dykelets.
Both the North and Main Dykes have spodumene-rich zones (muscovite-K-feldspar-quartz-green spodumene-albite) (Breaks et al., 2006, OFR6195). The spodumene in the North Dyke is very coarse-grained with blades up to 5 by 70 cm. The spodumene in the Main Dyke is abundant, very coarse-grained and green and white in colour. Horne’s sampling in 1999 located the Northeast Dyke and noted that it hosted very coarse-grained spodumene and a grab sample contained > 500 ppm Li and > 100 ppm Ta (MNDM assessment report: 32E04SW2002, 2000). It is recommended that follow up geological mapping of this dyke be completed.
Spodumene is absent in the beryl-type South Dyke and the potassic pegmatite East Dyke (MNDM assessment report: 32E04SW2004, 2001). The East Dyke consists mostly of grey, very coarse-grained K-feldspar, quartz and minor muscovite, quartz pods and aplite bands.
The Case Property contains multiple dykes exposed on the surface which suggests that additional blind pegmatite dykes could be present on the Property similar to the pegmatite dyke swarms at Whabouchi, Separation Rapids and Georgia Lake pegmatite fields. Platinova’s 2001 drill program only drilled 7 holes to a maximum depth of 84.71 m, so there is a potential to find additional pegmatite dykes at depth while still being suitable for open pit mining.
In September 1999, Joseph Horne of Cardinal Exploration Services completed 4500 m2 mechanical stripping and selected power washing on the North, Main and South Dykes (MNDM assessment report 32E04SW2002). Joseph Horne’s regional prospecting in October 1999 lead to the discovery of the Northeast dyke with very coarse-grained spodumene and > 500 ppm Li and > 100 ppm Ta. In November 1999, he collected two plugger hole sample series normal to the strike across the North Dyke.
In summer 2001, Platinova A/S completed 7 drill holes totaling 508.76 m on the Case property to investigate the Ta/Nb contents of the pegmatite dykes. These holes were drilled on 5 sections across Main and North Case Pegmatite Dykes on claim 1213780 (MNDM assessment report: 32E04SW2003, 2001). Platinova also completed geological mapping at 1:200 scale on a 10 m grid and sampling of 6 channels totaling 113.1 m on North, Main and South Dykes.
Assay highlight from Platinova’s channel sampling on the Main Dyke:
- SC-3, sample 23549, 12,700 ppm Li, 186 ppm Cs, 1,330 ppm Rb, >100 ppm Be and 376 ppm Ta.
In September 2010, Fieldex Exploration Inc. resampled Platinova’s 7 drill holes (Fieldex press release dated Sept. 13, 2010). The assay highlights include:
- DDH-1 from 23.80 to 33.00 m with 1.98 % Li2O over 9.20 m
- DDH-4 from 43.32 to 47.72 m with 1.49 % Li2O over 4.40 m
- DDH-5 from 43.00 to 57.07 m with 1.35 % Li2O over 14.07 m
Power Metals 2017 sampling
Platinova’s 7 drill holes were relogged and resampled by Caracle Creek January 2017.
Case pegmatite assays has 45 assays out of a total of 234 drill core assays with > 0.43 % Li2O cut off which represents 19% of the total assays. Some of the assay highlights on the Main Dyke spodumene zone include:
- DDH-1 from 22.70 to 33.00 m with 1.98 % Li2O over 10.30 m
- DDH-5 from 46.57 to 56.00 m with 1.37 % Li2O over 9.43 m
- DDH-5 from 45.00 to 45.95 m with 3.24 % Li2O over 0.95 m.