- Published: 23 March 2017
- Written by Editor
First Mining releases 43-101 Cameron resource estimate
OPEN-PIT AND UNDERGROUND MINERAL RESOURCE ESTIMATES AT CAMERON, EFFECTIVE JAN. 17, 2017
Mineral resource classification Open-pit constraint Gold cut-off Tonnes Gold Gold
(Au g/t) g/t (ounces)
Measured mineral resource Within $1,350 open-pit shell 0.55 2,670,000 2.66 228,000
Indicated mineral resource Within $1,350 open-pit shell 0.55 820,000 1.74 46,000
Measured + indicated 3,490,000 2.45 274,000
Mineral resource classification Underground constraint Gold cut-off Tonnes Gold Gold
(Au g/t) g/t (ounces)
Measured mineral resource Below $1,350 open-pit shell 2.00 690,000 3.09 69,000
Indicated mineral resource Below $1,350 open-pit shell 2.00 1,350,000 2.80 121,000
Measured + indicated 2,040,000 2.90 190,000
Total measured + indicated 5,530,000 2.61 464,000
Mineral resource classification Open-pit constraint Gold cut-off Tonnes Gold Gold
(Au g/t) g/t (ounces)
Inferred mineral resource Within $1,350 open-pit shell 0.55 35,000 2.45 3,000
Mineral resource classification Underground constraint Gold cut-off Tonnes Gold Gold
(Au g/t) g/t (ounces)
Inferred mineral resource Below $1,350 open-pit shell 2.00 6,500,000 2.54 530,000
Total inferred 6,535,000 2.54 533,000
The mineral resource estimate is classified as measured, indicated and inferred mineral resources.
The 2014 CIM (Canadian Institute of Mining, Metallurgy and Petroleum) definition standards were
followed for classification of mineral resources.
The mineral resource has been estimated using a gold price of $1,350 (U.S.) per ounce.
The mineral resource was estimated using a block model. Three-dimensional wire frames were generated
using geological information. The ordinary kriging estimation method was used to interpolate
grades into blocks. Blocks were subblocked to more accurately reflect the volume of the wire frames.
Mineral resources that are not mineral reserves do not have demonstrated economic viability. There
is currently insufficient exploration to define these inferred mineral resources as indicated or
measured mineral resources, and it is uncertain if further exploration will result in upgrading
them to an indicated or measured mineral resource category.
Numbers may not add due to rounding.
The Cameron gold deposit is a shear-hosted gold deposit within a structurally complex belt of arcuate greenstones and felsic intrusive bodies. The regional controls are well documented in terms of the major structural elements and their interactions. The local geology has been mapped at the surface in trenches and outcrops and also in underground drift development. There has been extensive drilling coverage of the deposit from surface and underground, and the information used in developing the estimate is exclusively from high-quality diamond drilling samples and logging.
Gold is associated with disseminated pyrite with high sulphide concentration generally corresponding with higher gold grades. The mineralization is open at depth and along strike to the northwest with potential to expand the mineral resource in these directions.
The mineral resource estimate for Cameron has been updated using an additional 30,000 samples, which, combined with the relogging of approximately 771 diamond holes (103,000 metres), has increased the confidence of the geological and mineralization interpretations. The definition of grade domains and continuity is considered to be robust and with greater confidence at a more local scale than previous estimates due to the much greater number of samples.
The interpretation of the deposit-scale geological model was done in a collaborative manner, with the Cameron site geological team (which was responsible for the relogging of the drilling) involved in the interpretation of sectional and wire frame interpretations of the geology and mineralization. These interpretations were used by Optiro as a guide to compile the 3-D geological model using Leapfrog Geo 3-D software. The geological modelling process was iterative with discussions and amendments made to validate the definition of the lithological and structural elements into an integrated model.
With respect to the tonnage and metal risk, the volumetric controls of thickness and extent of the mineralized domains are considered to be robust and well constrained by the geological interpretations. The density assignment is based on the results of 1,202 measurements that were grouped by lithology. The average values assigned are considered to be representative of the lithologies present.
A kriging neighbourhood analysis (KNA) was undertaken to determine the optimal block size, to test for the optimal search ellipse orientation and dimensions, and to test the minimum and maximum numbers of samples to be used for grade estimation. This analysis used the variogram limits and an iterative series of estimates with varying block size, search and sample number, using kriging efficiency (KE) and slope of regression (slope) values to provide a metric of estimation performance.
Discrete areas that represent well-sampled areas (four to 15 metres of centred sampling), moderately (15 to 50 metres of centred sampling) and poorly (more than 50 metres of sampling) were identified for each of the significant lodes (FW1, MID, Main and HW). The contrast in available sample density makes selection of the parent cell size and search strategy an exercise in compromise between efficiency in undertaking the estimate, reliability of the estimate and reflecting the known geology.
The mineral resources have been reported using two Au cut-off grades. The parts of the deposit considered amenable to open-pit mining methods have been reported using a 0.55-gram-per-tonne-cut-off grade applied within a constraining Whittle open-pit shell down to a depth of 235 metres below natural surface. Below this, the deposit has been reported at a 2.00-gram-per-tonne-cut-off grade, which is considered to be appropriate for underground mining using the long-hole open-stoping method. A gold price of $1,350 (U.S.) and metallurgical recovery of 91.5 per cent has been used. The limits for the optimization process and assumptions for open-pit and underground mining are included in the attached Cameron open-pit and underground limits table.
CAMERON OPEN-PIT AND UNDERGROUND LIMITS Limits Open pit Underground Mining cost U.S.$/t $2.00 $55.50 Milling cost U.S.$/t $20.00 $20.00 G&A cost U.S.$/t 2.50 2.50 Overall cost U.S.$/t 24.50 78.00 Au met. recovery % 91.5% 91.5% Au price U.S.$/oz 1,350 1,350 Cut-off Au g/t 0.55 2.00
Qualified persons
Dr. Chris Osterman, PGeo, chief executive officer of First Mining, is a qualified person as defined by National Instrument 43-101 and has reviewed and approved, and accepts responsibility for, the technical information contained within this press release. Mark Drabble, MAIG, MAusIMM, and Kahan Cervoj, MAIG, MAusIMM, principal consultants with Optiro Pty. Ltd., are the authors of the technical report, and each of them is an independent qualified person within the meaning of NI 43-101.
Neither Mr. Drabble, Mr. Cervoj nor any associates employed by Optiro in the preparation of the technical report have any beneficial interest in First Mining. These consultants are not insiders, associates or affiliates of First Mining. The results of this technical report are not dependent upon any prior agreements concerning the conclusions to be reached, nor are there any undisclosed understandings concerning any future business dealings between First Mining and the consultants. The consultants are paid a fee for their work in accordance with normal professional consulting practices.
About the Cameron project
The Cameron gold project was acquired by First Mining from Chalice on June 9, 2016. The project, which covers an area of over 44,853 hectares (110,835 acres), is located in Northwestern Ontario, approximately 75 kilometres southeast of Kenora and approximately 30 kilometres southeast of the township of Pickle Lake.
About First Mining Finance Corp.
First Mining is a mineral property holding company whose principal business activity is to acquire high-quality mineral assets with a focus in the Americas. The company currently holds a portfolio of 25 mineral assets in Canada, Mexico and the United States with a focus on gold. Ultimately, the goal is to continue to increase its portfolio of mineral assets through acquisitions that are expected to be composed of gold, silver, copper, lead, zinc and nickel.
