Dr. Donald Robinson reports
EASTMAIN RELEASES UPDATED MINERAL RESOURCE STATEMENT
Eastmain Resources Inc. has released an updated mineral resource statement for its wholly owned Eau Claire gold deposit, part of the Clearwater project, located within the James Bay region of Quebec. This new mineral resource statement demonstrates that Eau Claire is one of the highest-grade open-pit prospects, with potential for economic extraction, in North America. In addition, there remains excellent exploration potential to further expand the size and improve the grade of this pit-constrained mineral resource, both at depth and along strike.
The mineral resource statement, as prepared by SRK Consulting (Canada) Inc., is presented in the Mineral resource statement table. SRK considers that portions of the Eau Claire gold deposit are amenable for open-pit extraction, while other (deeper) parts of the deposit could be extracted using an underground mining method. With the completion of the mineral resource estimate, Eastmain intends to initiate a preliminary economic assessment, overseen by Serge Bureau, MSc, PEng, technical adviser, mining development group, for Eastmain.
Highlights:
- Open-pit measured and indicated gold resources increased by 53 per cent to
885,000 ounces of contained gold while maintaining an exceptional grade
of 4.05 grams per tonne gold.
- Open-pit inferred gold resources contain 110,000 ounces of contained
gold at a grade of 3.12 grams per tonne gold.
- Closely spaced composite surface channel sample grades are 81 per cent higher,
at 13.2 grams per tonne, than measured open-pit gold resources, suggesting that
additional drilling and sampling have excellent potential to increase
contained gold ounces significantly.
- Increased geological and geostatistical confidence in the continuity of
high-grade gold mineralization, as a result of approximately 70,000
metres of drilling completed entirely in the upper one-third of the deposit,
demonstrates Eau Claire's potential for economic extraction.
Definition drilling since the last mineral resource estimate focused entirely on increasing both the quality and quantity of gold resources within the upper one-third of the Eau Claire gold deposit, resulting in the expansion of measured and indicated open-pit mineral resources by 53 per cent to 885,000 ounces of contained gold within 6.8 million tonnes at a grade of 4.05 grams per tonne gold.
"We are extremely pleased with this new mineral resource statement," stated Dr. Don Robinson, president and chief executive officer. "The company has significantly upgraded inferred open pit mineral resources to measured and indicated mineral resource categories in the upper portion of the deposit, where internal scoping studies indicate that the driving catalyst for potential future economic extraction is the viability of the open pit."
Resource potential
Potential to improve resource grades
Based on Eastmain's work to date, which clearly shows an increase in grade with increased drilling or sample density, there is substantial potential to continue to increase both grade and tonnage of the open-pit and underground mineral resources at Eau Claire.
Open-pit gold resource grades systematically increase with the amount of drilling completed -- from 3.12 grams per tonne gold in the inferred category, where drill spacing in the third dimension exceeds 25 metres; to 4.05 grams per tonne gold in the measured and indicated category, where drill hole spacing provides greater confidence at 25 metres; and to 7.29 grams per tonne gold (8.71 grams per tonne gold uncapped) defined as measured mineral resources, where there is the greatest confidence due to more closely spaced drilling. Furthermore, the mean grade calculated from 486 composite surface channel samples in the 450 West zone, at 13.2 grams per tonne gold, is 81 per cent higher than the measured mineral resource grade.
Refined geological model
Drilling completed at Eau Claire since 2012 has significantly improved confidence in the geological and the geostatistical continuity of gold mineralization between sample points within the upper portions of the deposit. Three generations of gold mineralization have been defined within the 450 West zone. It has become apparent that where two or more gold-bearing structures intersect, a marked increase in grade and/or thickness results. The company's new 3-D modelling of the deposit, based on these drill results, has not only provided insight into the geological controls of mineralization at Eau Claire, but may also provide a predictive method of interpreting where these sweet spots may occur.
Deposit and regional-scale exploration potential
There is excellent potential to add to open-pit and underground measured and indicated mineral resources with additional drilling below and lateral to the conceptual pit shell, used to constrain the open pit resources. There is also significant potential for additional discoveries within the Eau Claire belt, where anomalous gold-bearing rock samples have been defined along a key mineralized corridor for over 7.5 kilometres.
Historical wide-spaced drilling, completed prior to 2006, has defined a large footprint of inferred mineral resources, mainly within the lower two-thirds of the deposit, extending for 500 metres east of the conceptual pit shell and to a vertical depth of 900 metres, where no recent drilling has been completed. The new geologically constrained block model mineral resource estimate delivers very similar underground inferred mineral resource tonnages as the previous estimate. However, with the change in resource estimation methodology, where geostatistical confidence is less certain, due to wide drill hole spacing, inferred gold resource grade and therefore the number of contained inferred gold ounces has decreased. As such, a number of gold-bearing quartz-tourmaline veins were modelled as vein swarms by SRK, resulting in a dilution of grade for these intervals. Further drilling is required to improve geological confidence and geostatistical continuity of quartz-tourmaline veins and gold-tellurium mineralization contributing to these inferred mineral resources, particularly at depth.
Eau Claire is a very complex high-grade gold deposit with an abundant tellurium byproduct. There is approximately 36,000 kilograms of tellurium contained in the measured and indicated open-pit mineral resources at a grade of 5.38 grams per tonne tellurium, which is slightly higher than the average gold grade. This rare metal, which is in relatively short supply, has a very strong correlation to gold at Eau Claire and may contribute to the future economics of the deposit. The value of tellurium was not considered in SRK's preparation of the mineral resource statement.
2015 program recommendations
In addition to commencing work on a preliminary economic assessment, a $2-million exploration program has been allocated for the Clearwater project for 2015. This proposal includes definition drilling below and lateral to the conceptual pit shell at the Eau Claire gold deposit, part of the Clearwater project, to expand open-pit and underground mineral resources. It also comprises surface exploration along the Eau Claire gold belt in search of a second gold deposit on the property.
Updated mineral resource statement
The mineral resource statement is based on results from an additional 183 drill holes (72,859 metres) and 189 channel samples (940 metres) completed since the last mineral resource estimate (see the company's news release in October, 2012).
MINERAL RESOURCE STATEMENT (1, 2), EAU CLAIRE GOLD DEPOSIT, QUEBEC
SRK CONSULTING (CANADA), APRIL 27, 2015
Category Tonnage Grade Contained metal
Gold Tellurium Gold Tellurium
(000 t) Au (g/t) Te (g/t) Au (oz) Te (kg)
Open-pit (2) mineral
resources
Measured 970 7.29 10.18 227,000 9,900
Indicated 5,827 3.51 4.58 658,000 26,700
----- ---- ----- ------- ------
Measured and indicated 6,797 4.05 5.38 885,000 36,600
Inferred 1,098 3.12 3.63 110,000 4,000
Underground (2) mineral
resources
Measured - - - - -
Indicated 428 4.78 6.07 66,000 2,600
----- ---- ----- ------- ------
Measured and indicated 428 4.78 6.07 66,000 2,600
Inferred 3,974 4.09 3.12 523,000 12,400
Combined mineral
resources
Measured 970 7.29 10.18 227,000 9,900
Indicated 6,255 3.60 4.68 724,000 29,300
----- ---- ----- ------- ------
Measured and indicated 7,225 4.09 5.42 951,000 39,200
Inferred 5,072 3.88 3.23 633,000 16,400
Notes:
(1) Mineral resources are not mineral reserves and as such have not
demonstrated economic viability. All figures are rounded to reflect the
relative accuracy of the estimate. Composites have been capped where
appropriate.
(2) Open-pit mineral resources are reported at a cut-off grade of 0.5 g/t
gold within a conceptual pit shell and underground mineral resources are
reported at a cut-off grade of 2.5 g/t gold outside the conceptual pit
shell. Cut-off grades are based on a gold price of $1,300 (U.S.) per ounce,
a foreign exchange of 90 U.S. cents to $1 and a gold recovery of 95 per
cent. The value of tellurium has not been considered.
Mineral resource estimation methodology
The current mineral resource model was prepared by SRK using a geostatistical block modelling approach. This model is constrained by a revised interpretation of Eau Claire deposit geology in the form of three-dimensional wireframes for geology and gold mineralization constructed by SRK, with the assistance of Eastmain's new geological interpretation and their understanding of the Eau Claire gold deposit.
The resource database comprises 111,541 assay records, used in conjunction with interpreted geology to construct various domains throughout the deposit. The block model includes 144 quartz-tourmaline vein domains, defined by individual veins and their associated alteration intervals; and 73 vein swarm domains, defined as wider zones of intermittent quartz-tourmaline veining and associated alteration, where drilling density is insufficient to model individual veins with confidence. Gold mineralization found within lithological units outside of these modelled domains (wireframes) was also considered.
Gold and tellurium grades were assigned to block model cells, using ordinary kriging, informed from capped gold and tellurium composite data. After validation, block estimates were classified into measured, indicated and inferred resource categories based on geological confidence, geostatistical continuity and the density of the informing data.
SRK considers that a portion of the gold and tellurium mineralization found at the Eau Claire gold deposit is amenable to open-pit extraction, while deeper portions located outside a conceptual pit shell could be amenable for underground extraction. SRK used a Whittle pit optimizer to evaluate those portions of the block model which could reasonably be expected to be mined by open-pit methods.
Mineral resources have been estimated in conformity with CIM Mineral Resource and Mineral Reserves Estimation Best Practices Guidelines (November, 2003) and are classified according to the CIM Definition Standards for Mineral Resources and Mineral Reserves (May, 2014) guidelines. The mineral resource statement is reported in accordance with Canadian Securities Administrators' National Instrument 43-101.
Mineral resource sensitivity studies
Eau Claire mineral resources are sensitive to the selection of reporting assumptions. To illustrate this sensitivity, classified global quantities and grade estimates for the open-pit and underground portions of the block model at various cut-off grades, with and without capping, are presented in the Sensitivity of block model table. The reader is cautioned that the figures presented should not be misconstrued as a mineral resource statement. The reported quantities and grade estimates are only presented as a sensitivity of the resource model to the selection of a reporting cut-off grade and to capping.
SENSITIVITY OF BLOCK MODEL QUANTITY AND GRADE ESTIMATES(i)
TO CUT-OFF GRADE AND CAPPING
Cut-off grade (g/t Au) Quantity (Mt) Grade Contained metal
Au Te Au Te
(g/t) (ppm) (oz) (kg)
Open-pit material
measured and indicated capped
0.3 9.2 3.08 4.15 915,000 38,300
0.4 7.7 3.62 4.83 898,000 37,300
0.5 6.8 4.05 5.38 885,000 36,600
1.0 4.9 5.38 7.06 842,000 34,300
1.5 4.1 6.16 8.03 812,000 32,900
2.0 3.6 6.77 8.79 784,000 31,600
Inferred capped
0.3 1.7 2.14 2.50 118,000 4,300
0.4 1.3 2.69 3.13 113,000 4,100
0.5 1.1 3.12 3.63 110,000 4,000
1.0 0.6 4.80 5.73 100,000 3,700
1.5 0.5 5.61 6.83 96,000 3,600
2.0 0.5 6.14 7.52 92,000 3,500
Underground material
Measured and indicated capped
1.0 1.4 2.57 3.17 112,000 4,300
2.0 0.6 4.01 5.02 79,000 3,100
2.5 0.4 4.78 6.07 66,000 2,600
3.0 0.3 5.56 7.01 56,000 2,200
4.0 0.2 6.99 8.76 42,000 1,600
5.0 0.1 8.45 10.78 32,000 1,300
Inferred capped
1.0 13.6 2.29 1.93 1,001,000 26,200
2.0 5.6 3.56 2.74 637,000 15,300
2.5 4.0 4.09 3.12 523,000 12,400
3.0 3.0 4.54 3.48 436,000 10,400
4.0 1.6 5.48 4.38 281,000 7,000
5.0 0.6 7.00 6.35 146,000 4,100
Open-pit material
Measured and indicated uncapped
0.3 9.2 3.39 4.56 1,003,000 42,000
0.4 7.7 3.98 5.32 987,000 41,000
0.5 6.8 4.46 5.93 973,000 40,300
1.0 4.9 5.95 7.83 930,000 38,100
1.5 4.1 6.82 8.93 901,000 36,700
2.0 3.6 7.50 9.78 873,000 35,400
Inferred uncapped
0.3 1.8 2.23 2.60 131,000 4,700
0.4 1.4 2.77 3.21 127,000 4,600
0.5 1.2 3.20 3.71 123,000 4,500
1.0 0.7 4.80 5.76 113,000 4,200
1.5 0.6 5.71 6.98 107,000 4,100
2.0 0.5 6.39 7.90 102,000 3,900
Underground material
Measured and indicated uncapped
1.0 1.4 2.74 3.29 120,000 4,500
2.0 0.6 4.34 5.22 87,000 3,200
2.5 0.4 5.23 6.35 73,000 2,800
3.0 0.3 6.13 7.38 63,000 2,400
4.0 0.2 7.72 9.25 50,000 1,900
5.0 0.1 9.25 11.47 41,000 1,600
Inferred uncapped
1.0 14.4 2.33 1.85 1,077,000 26,600
2.0 5.8 3.69 2.67 687,000 15,500
2.5 4.1 4.27 3.05 568,000 12,600
3.0 3.1 4.77 3.42 480,000 10,700
4.0 1.8 5.71 4.20 333,000 7,600
5.0 0.9 7.10 5.55 199,000 4,800
(i) The reader is cautioned that the figures presented in this table should
not be misconstrued as a mineral resource statement. The reported quantities
and grades estimates are only presented as a sensitivity of the estimates to
the selection of cut-off grade and capping levels.
Qualified persons
The geological model was constructed by Dr. Jean-Francois Ravenelle, PGeo. The mineral resource statement was prepared by Dominic Chartier, PGeo, with the assistance of Dr. Jean-Francois Couture, PGeo. Dr. Ravenelle, Mr. Chartier and Dr. Couture are full-time employees of SRK and qualified persons under National Instrument 43-101 and are independent of the company. They have reviewed and approved the information contained in this news release.
Dr. Donald J. Robinson, PGeo, president and chief executive officer of Eastmain, reviewed and approved the technical data presented in this press release. Dr. Robinson who has sufficient experience relevant to the style of mineralization under consideration is a qualified person as defined by National Instrument 43-101.
Drill program and sampling protocol is managed by Eastmain under the supervision of Dr. Robinson. Diamond drill holes are HQ sized and core recovery to date exceeds 98 per cent. Drill core is logged, photographed and then cut in half by rock saw, with half-core samples securely shipped to ALS Chemex Laboratories of Sudbury on a weekly basis. Sample lengths are generally 0.5 metre for vein and alteration material, whereas adjacent non-mineralized and unaltered rock is sampled at one-metre intervals. For quality assurance/quality control purposes, in addition to lab blanks and standards, the company inserts alternating blanks and standards every 25 samples. Standards are purchased from Analytical Solutions of Toronto. Gold analyses reported for this release were performed by standard fire-assay using a 50-gram split with an inductively coupled plasma finish. A second 50-gram split was assayed using atomic absorption spectroscopy finish for samples containing greater than 500 parts per billion gold and a further assay was performed using, a gravimetric finish for samples containing greater than five grams per tonne gold. Certain samples containing visible gold were also analyzed using a metallic screen procedure. All samples were also analyzed for a multielement suite using an aqua regia digestion with ICP-AES finish.
Conference call today: Monday, April 27, 2015, at 10 a.m. ET
Toll-free: 1-888-231-8191
Local and international: 647-427-7450
Speakers:
Dr. Don Robinson, president and chief executive officer, Serge Bureau, technical adviser, mining development group
Conference call replay
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Local: 1-416-849-0833
Password: 33612421
Please note the conference call replay will be available until May 11, 2015.
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