[ 1 ] Values for the Pt, Pd and Au components of TPM are shown in Table 5 and Table 6. [ 2 ] All tonnages are reported as short tons.
Significant Increase in the TMM Global Resource
The study includes three mineral resources in close proximity to one another within the Twin Metals Minnesota Project referred to as the Maturi, Birch Lake and Spruce Road Deposits:
- Using a base case 0.3% Cu cut-off, the Maturi Deposit** contains 1065 million tons of Indicated Mineral Resources grading 0.59% copper, 0.19% nickel, 0.60 parts per million TPM (TPM = Pt + Pd + Au), plus an additional 542 million tons of Inferred Mineral Resources grading 0.51% copper, 0.17% nickel, 0.53 parts per million TPM. (Maturi Deposit tonnages do not include 139 million tons of mineralized material excluded from the underground resource in a safety pillar)
- Using a base case 0.3% Cu cut-off, the Birch Lake Deposit** contains 99.7 million tons of Indicated Mineral Resources grading 0.52% copper, 0.16% nickel, 0.86 parts per million TPM, plus an additional 239.2 million tons of Inferred Mineral Resources grading 0.46% copper, 0.15% nickel, 0.64 parts per million TPM
- Using a base case 0.3% Cu cut-off, the Spruce Road Deposit** contains 480 million tons of Inferred Mineral Resources grading 0.43% copper, 0.16% nickel.*
* Note - The Spruce Road resource was estimated using Inco legacy assay data. Platinum, palladium, and gold were not assayed by Inco, and the core is not available for re-assay.** Note - These mineral resource estimates include 100% of the estimated resource in each deposit, and include mineral resources acquired as a part of TMM's acquisition of Franconia Minerals Corporation in 2011. Franconia's principal assets are a 70% interest in the Birch Lake, 'old' Maturi and Spruce Road deposits in northeastern Minnesota through the Birch Lake Joint Venture. Franconia announced in November, 2010 its intention to increase its ownership at the Birch Lake Joint Venture to 82%; see Franconia 's company profile at http://www.SEDAR.com for Technical Reports. TMM's ownership of the resource will be factored by these percentages where applicable. Higher Grade core delineated in the Maturi Deposit - Potential Earlier Economic Mining Opportunities The current Maturi Deposit resource estimate is based on a refined geological model. One geological subunit within the Maturi Deposit, known as the S3, hosts a higher-grade area that is a subset of the base case mineral resource estimate that may have potential as an early start-up area. AMEC estimated that the S3 Subunit in the Maturi Deposit, using a 0.5% Cu cut-off, contains 622 million tons grading 0.69% Cu, 0.22% Ni and 0.76 ppm TPM of Indicated Mineral Resources and 198 million tons grading 0.65% Cu, 0.21% Ni and 0.82 ppm TPM in the Inferred category. This material is a higher grade sub-set of the global resources estimated for Maturi. Within the Maturi Deposit, the bulk of mineralization is hosted by two subunits of the Basal Mineralized Zone (BMZ). The S2 and S3 subunits are stratiform, with the S3 subunit overlying the S2 subunit. Both subunits are laterally extensive, and are present over the vast majority of the deposit footprint. Within the Indicated Mineral Resource areal footprint, the S3 subunit ranges in vertical thickness from 0 to 355 feet, averaging 108 feet thick (0 to 276 feet, average 91 feet true thickness) and within the Indicated Mineral Resource areal footprint, the S2 subunit ranges in vertical thickness from 0 to 423 feet, averaging 72 feet thick (0 to 329 feet, averaging 59 feet true thickness). Table 1 shows tabulation range of sensitivity cases at different copper cut-off grades for the S3 Subunit of the Maturi Deposit. The base case subset estimate at a 0.3% Cu cut-off grade for the unit is shown in bold, and the 0.5% Cu cut-off grade sensitivity case subset is indicated in italics. Table 1 - Maturi Deposit S3 Subunit Sensitivity case Indicated and Inferred Mineral Resources
Maturi Deposit- S3 Subunit Indicated Mineral Resource Cu% Million Cu Ni Pt Pd Au TPM cut-off Tons % % ppm ppm ppm ppm 0.2 643 0.68 0.22 0.20 0.45 0.11 0.75 0.3 643 0.68 0.22 0.20 0.45 0.11 0.75 0.4 641 0.68 0.22 0.20 0.45 0.11 0.75 0.5 622 0.69 0.22 0.20 0.45 0.11 0.76 0.6 500 0.72 0.23 0.21 0.47 0.11 0.78 Inferred Mineral Resource Cu% Million Cu Ni Pt Pd Au TPM cut-off Tons % % ppm ppm ppm ppm 0.2 234 0.62 0.20 0.21 0.46 0.10 0.77 0.3 232 0.62 0.20 0.21 0.47 0.10 0.78 0.4 225 0.63 0.20 0.21 0.47 0.10 0.78 0.5 198 0.65 0.21 0.22 0.50 0.11 0.82 0.6 129 0.70 0.22 0.25 0.55 0.12 0.92Significant Increase in Contained Metals from June 2012: Contained metals in the new resources are shown in Table 2: