The Escape Lake Intrusion and magma conduit appears to be a twin structure to the Current Lake Intrusion and magma conduit on the Thunder Bay North Project (Figure 1).
Figure 1: 3D Oblique View of the Thunder Bay North Escape Lake and Current Lake Magma Conduit System
Table 1: Thunder Bay North Project – Grade Summary
Note: See section "Input Parameters for Resource Calculation" below.
Table 2: Thunder Bay North Project – Contained Metals
Table 3: Current Lake Deposit – Grade Summary
Table 4: Current Lake Deposit – Contained Metals
Table 5: Escape Lake Deposit – Grade Summary
Table 6: Escape Lake Deposit – Contained Metal
Input Parameters for Resource Calculation
Mining Cutoff Grade
The cutoff value used for the mineral resource is US$77/tonne (CA$101/tonne) insitu contained value, 1.58g/tonne Palladium Equivalent (PdEq) (US$77 / (US$1,516.82/31.10305)) or 2.65g/tonne Platinum Equivalent (US$77 / (US$902.38/31.10305)). The cutoff value is calculated based on estimations as follows: direct mining operating cost, onsite milling operating cost, tailings management facility operating cost, indirect operating cost, general and administration (G&A) cost, onsite milling metal recoveries, offsite smelting metal recoveries, and smelter metal payable percentages. A total estimated operating cost of CA$66.91/tonne of mill feed is comprised of;
Onsite estimated mill metal recoveries, offsite estimated smelting metal recoveries and estimated smelter payable percentages used for mineral resource cutoff grade calculations are summarized in Table 7. For resource cutoff calculation purposes, a mining recovery of 100.0% and 0.0% mining dilution were applied. The applicable metal prices are summarized in Table 8.
Table 7: Contained Metals Parameters of Mineral Resource Cutoff Grade Calculations
Note: Values taken from Panoramic Resources “AMEC Technical Report dated 6 October 2010”.
Nordmin examined and modelled the mineralization within the Current Lake and Escape Lake deposits for the purpose of grade concentration and isolation of composites, while including lithological, geochemical, and structural correlations between rock types that are influencing the mineralization at each respective deposit.
Domain wireframes were modelled for seven grade elements, including combined Platinum (“Pt”) and Palladium (“Pd”), Gold (“Au”), Silver (“Ag”), Copper (“Cu”), Nickel (“Ni”), Cobalt (“Co”), and Rhodium (“Rh”). Each domain was built using geology, mineralization, and grade bin for a combination of Background grade (“BG”), Low Grade (“LG”), Medium Grade (“MG”), and High Grade (“HG”). Background grades were isolated through applying the overall conduit wireframe. The criteria include:
Current Lake Deposit
Escape Lake Deposit
Wireframes were initially created on 10 m to 20 m plan sections and adjusted on vertical section views to edit and smooth each wireframe where required. When not cut off by drilling, the wireframes terminate at the contact of the conduit or due to lack of drilling, whichever was most appropriate. No wireframe overlapping exists within a given domain, but all domains are independent of each other.
The use of explicit modelling allows for mineralization in context with the deposit geology and associated geochemistry to be considered. It is Nordmin’s opinion that the explicit modelling approach minimizes risks compared to using implicit modelling for each deposit.
Compositing of samples is a technique used to give each sample a relatively equal length to reduce the potential for bias due to uneven sample lengths; it prevents the potential loss of sample data and reduces the potential for grade bias due to the possible creation of short and potentially high-grade composites that are generally formed along the zone contacts when using a fixed length.
The raw sample data was found to have a relatively narrow range of sample lengths. Samples captured within all zones were composited to 1.0 m regular intervals based on the observed modal distribution of sample lengths, which supports a 5.0 m x 5.0 m x 5.0 m block model (with sub-blocking). An option to use a slightly variable composite length was chosen to allow for backstitching shorter composites that are located along the edges of the composited interval. All composite samples were generated within each mineral lens with no overlaps along boundaries. The composite samples were validated statistically to ensure there was no loss of data or change to the mean grade of each sample population.
Block Model Resource Estimation
A “soft boundary” was used for the application of composites for all mineralized domains except for the background domains, as follows:
A series of upfront test modelling was completed to define an estimation methodology to meet the following criteria:
Multiple test scenarios were evaluated to determine the optimum processes and parameters to use to achieve the stated criteria. Each scenario was based on Natural Neighbour (NN), Inverse Distance Squared (ID2), Inverse Distance Cubed (ID3), and Ordinary Kriging (OK) spatial interpolation and weighted averaging methods.
All test scenarios were evaluated based on global statistical comparisons, visual comparisons of composite samples versus block grades, and the assessment of overall smoothing. Based on results of the testing, it was determined that the final resource estimation methodology would constrain the mineralization by using hard wireframe boundaries to control the spread of high to grade and low to grade mineralization. OK was selected as the best representative interpolation method.
Equivalency formulas were calculated and used for reporting purposes. The derivation of the equivalency formulas is based on accepted industry practices. All equivalencies are reported as in-situ grades and are calculated using the trailing average commodity price deck referenced in Table 8.
Platinum equivalency (“Pt Eq”) and Palladium Equivalency (“Pd Eq”) was calculated for each deposit through the following formulas, using components from platinum (“Pt”), palladium (“Pd”), gold (“Au”), silver (“Ag”), copper (“Cu”), nickel (“Ni”), cobalt (“Co”), and rhodium (“Rh”):
Table 8: Commodity Prices Used in Resource Calculation
Note: 3-year trailing average except Cobalt is 2-year trailing average.
The Mineral Resource estimate was independently prepared under the supervision of Mr. Glen Kuntz, P.Geo. (Ontario) of Nordmin Engineering Ltd., a "Qualified Person" under National Instrument 43-101 Standards of Disclosure for Mineral Projects. Verification included a site visit to inspect drilling, logging, density measurement procedures and sampling procedures, and a review of the control sample results used to assess laboratory assay quality. In addition, a random selection of the drill hole database results was compared with original records.
By providing your e-mail address, you are consenting to receive press releases, quarterly and annual reports, presentations and other information concerning Clean Air Metals Inc. and its affiliates and partners.