Northgate Minerals Intersects Highest Grade-Thickness Interval of 3.37 Grams per Tonne Gold and 0.95% Copper Over 60 Metres at its Kemess Underground Project
Eleven Drill Holes Intersect Significant Gold-Copper Mineralization
VANCOUVER, Sept. 15 /CNW/ - Northgate Minerals Corporation (TSX: NGX, NYSE Amex: NXG) is pleased to announce initial results from its infill diamond drilling program at its Kemess Underground Project ("Kemess UG"), located approximately five kilometres ("km") north of the existing Kemess South mine in north-central British Columbia.
Drilling Highlights
- Results from eleven new drill holes have encountered significant
gold-copper mineralization, exceeding previous resource block
estimates in the block cave zone by 22% for gold and 20% for copper.
- Hole KN-10-03 intersected 60 metres ("m") of 3.37 grams per tonne
("g/t") gold and 0.95% copper within a broader interval of 205 m,
which returned 1.28 g/t gold and 0.36% copper.
Hole KN-10-03 has returned the highest grade intercept in the
entire Kemess property.
- Hole KN-10-05 intersected 52 m of 2.38 g/t gold and 0.74% copper
within a broader interval of 273.3 m, which returned 0.98 g/t gold
and 0.381% copper.
- Hole KN-10-12 intersected 66 m of 1.71 g/t gold and 0.64% copper
within a broader interval of 196 m, which returned 1.12 g/t gold and
0.411% copper.
- Hole KN-10-10 intersected 92 m of 1.11 g/t gold and 0.59% copper
within a broader interval of 232 m, which returned 0.63 g/t gold and
0.391% copper.
- Hole KN-10-07A intersected 84.9 m of 1.26 g/t gold and 0.56% copper
within a broader interval of 272.3 m, which returned 0.59 g/t gold
and 0.295% copper.
Ken Stowe, President and Chief Executive Officer, remarked, "With half of the results in hand, the 2010 Kemess Underground infill program has already exceeded expectations by providing the best intercept in the resource database with hole KN-10-03. This result, supported by 2010 holes 05, 12, 10, 07A and three previous holes, demonstrates that a compact continuous higher grade zone exists in the north-eastern sector of the resource currently being considered for a bulk underground mining operation. Of particular significance is the fact that the 2010 results are consistently exceeding previous resource block estimates by 22% for gold and 20% for copper. We look forward to receiving the results from the remaining 2010 holes and incorporating them in a new underground resource to be completed in early 2011."
Overview of the Kemess Underground Project and 2010 Exploration Program
The Kemess UG diamond drill program was initiated in order to more precisely define the grade and geometry of the 70+ million tonne higher grade core of the Kemess North deposit within which previous drilling had defined a resource in excess of 1.4 million ounces of gold and 500 million pounds of copper.
This program was also designed to determine the geotechnical characteristics of the higher grade core and assess the potential for a large scale underground block cave operation using the Kemess South infrastructure, including the existing permitted tailings capacity in the Kemess South pit that could accommodate tailings produced from the block cave operation.
The 2010 diamond drill program at Kemess UG is now almost complete and final program results will be reported when assays from the remaining holes have been received.
Figure 1: Plan Showing Collar Locations of the First Eleven Holes Drilled
in 2010 Relative to Potential Block Cave Outline
www.northgateminerals.com/Theme/Northgate/files/Releases/KUG_Sep10Fig1.gif
2010 Drilling Results
Table 1 below summarizes intersections encountered to date during the 2010 drilling campaign. Intervals have been selected initially based on their position relative to a block cave mining outline designed from scoping study work completed earlier in 2010.
Table 1: Assay Results from 2010 Diamond Drill Holes
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Hole From (m) To (m) Interval (m) Gold (g/t) Copper %
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KN-10-01A 330.7 559.0 228.3 0.555 0.278
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including 447.0 489.0 42.0 0.883 0.389
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KN-10-02 461.3 607.3 146.0 0.633 0.307
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including 536.3 561.1 24.8 1.391 0.519
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KN-10-03 260.0 465.0 205.0 1.458 0.410
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including 312.0 372.0 60.0 3.365 0.955
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KN-10-04 248.0 609.0 361.0 0.366 0.208
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including 370.0 454.0 84.0 0.558 0.303
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KN-10-05 195.0 468.0 273.0 0.976 0.381
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including 326.0 436.1 110.1 1.779 0.601
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including 332.0 384.0 52.0 2.381 0.735
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including 360.0 378.0 18.0 3.377 1.007
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KN-10-07A 194.8 468.0 268.2 0.638 0.306
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including 312.1 397.0 84.9 1.257 0.563
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including 375.0 397.0 22.0 1.960 0.698
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KN-10-08 310.2 555.0 244.8 0.51 0.34
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including 425.0 470.0 45.0 0.95 0.52
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KN-10-09A 253.0 536.0 283.0 0.548 0.262
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including 374.0 454.0 80.0 1.105 0.514
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including 378.0 406.0 28.0 1.240 0.601
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including 430.0 454.0 24.0 1.258 0.468
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KN-10-10 274.0 506.0 232.0 0.634 0.391
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including 374.0 466.0 92.0 1.107 0.587
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including 414.0 432.0 18.0 1.553 0.910
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KN-10-12 320.0 516.0 196.0 0.862 0.355
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including 419.0 485.0 66.0 1.714 0.640
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including 433.0 485.0 52.0 1.786 0.682
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including 457.0 485.0 28.0 2.208 0.686
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KN-10-14 327.0 595.5 268.5 0.390 0.236
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including 430.0 491.0 61.0 0.571 0.302
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2010 Results Compared to 2005 Open Pit Resource
Comparison of 2010 results to date against the previous 2005 Kemess North resource shows that the assay results from the current program are, on average, 22% higher for gold and 20% higher for copper than predicted by an average of resource blocks captured by a 20 x 20 m prism centered on the drill hole trace.
Table 2: 2010 Diamond Drill Results Compared to 2005 Resource Model
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2005
2010 DDH Block Model Difference
From To Width Gold Copper Gold Copper (%)
Hole No. (m) (m) (m) g/t % g/t % Gold Copper
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KN-10-01A 330.7 559.0 228.3 0.555 0.278 0.548 0.286 1% -3%
KN-10-02 461.3 607.3 146.0 0.633 0.307 0.401 0.203 58% 51%
KN-10-03 260.0 465.0 205.0 1.458 0.41 0.744 0.237 96% 73%
KN-10-04 248.0 609.0 361.0 0.366 0.208 0.373 0.244 -2% -15%
KN-10-05 195.0 468.0 273.0 0.976 0.381 0.819 0.323 19% 18%
KN-10-07A 194.8 468.0 273.3 0.638 0.306 0.529 0.236 21% 30%
KN-10-08 310.2 555.0 244.8 0.506 0.343 0.517 0.279 -2% 23%
KN-10-09A 253.0 536.0 283.0 0.548 0.262 0.472 0.21 16% 25%
KN-10-10 274.0 506.0 232.0 0.634 0.391 0.554 0.323 14% 21%
KN-10-12 320.0 516.0 196.0 0.862 0.355 1.015 0.384 -15% -8%
KN-10-14 343.0 388.0 45.0 0.43 0.207 0.321 0.196 34% 6%
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Mean Difference 22% 20%
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An explanation of this difference is that the 2005 resource model is based on interpolation from wider spaced drilling that was unconstrained with respect to important grade domains existing within the resource. The net effect is to over-estimate low grade regions and under-estimate high grade regions. Future resource estimation will account for this.
The eastern tier of holes contains the highest grade-thicknesses in the history of drilling at Kemess and are fault bound to the east. Previous exploration east across this structure has been successful in identifying three zones of similar gold-copper mineralization in the Kemess East area (see Figure 2).
Figure 2: Plan Showing Potential Block Cave Outline Relative to Other
Gold Copper Mineralization at Kemess East
www.northgateminerals.com/Theme/Northgate/files/Releases/KUG_Sep10Fig2.gif
Other Block Caving Exploration Targets within the Kemess Camp
The 2010 exploration program at Kemess targeted the Kemess North deposit, but there are several other currently known areas of higher grade mineralization immediately east of the the deposit (see figure 2) that are only sparsely drilled and will make attractive exploration targets for future years.
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Ora Zone
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Hole From (m) To (m) Interval (m) Gold (g/t) Copper %
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KH-07-04 839.0 1296.3 457.3 0.37 0.39
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including 1105.0 1241.0 136.0 0.49 0.43
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including 1193.0 1241.0 48.0 0.62 0.45
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KH-07-10 912.5 1194.0 281.5 0.36 0.38
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including 1126.0 1145.4 19.4 0.56 0.51
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KH-07-24(*) 1195.1 1348.0 152.9 0.62 0.53
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including 1271.0 1329.0 58.0 0.73 0.58
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including 1295.0 1321.0 26.0 0.81 0.60
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(*) Hole terminated prematurely
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Offset Zone
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Hole From (m) To (m) Interval (m) Gold (g/t) Copper %
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KH-05-24 902.5 1029.6 127.1 0.35 0.235
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KN-05-27 1080.0 1206.0 126.0 0.24 0.318
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KN-05-28 914.0 1046.0 132.0 0.41 0.277
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Altus Zone
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Hole From (m) To (m) Interval (m) Gold (g/t) Copper %
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KH-07-05 142.0 258.2 116.2 0.24 0.330
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including 240.0 258.2 18.2 0.37 0.450
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Appendix 1: 2010 Diamond Drill Hole Collar Locations
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Eleva- Azi- Total
Hole No. Mine E Mine N NAD83E NAD83N tion muth Dip Depth Comment
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KN-10-01 10560 16182 636503 6326501 1681 255 -70 620 Abandoned
KN-10-01A 10560 16182 636504 6326502 1681 262 -75 602
KN-10-02 10513 16005 636462 6326324 1705 257 -72 642
KN-10-03 10706 16394 636642 6326718 1578 252 -71 504
KN-10-04 10402 16298 636341 6326612 1712 253 -69 633
KN-10-05 10714 16343 636651 6326668 1587 253 -71 561
KN-10-07 10599 16370 636536 6326691 1606 248 -70 339 Abandoned
KN-10-07A 10599 16370 636536 6326691 1606 248 -70 532
KN-10-08 10494 16244 636435 6326562 1685 176 -76 612
KN-10-09 10493 16246 636434 6326563 1685 000 -75 120.5 Abandoned
KN-10-09A 10494 16246 636435 6326564 1685 003 -74 620
KN-10-10 10735 16256 636676 6326582 1616 247 -66 575
KN-10-12 10604 16140 636549 6326461 1681 358 -59 624
KN-10-14 10264 16146 636209 6326456 1786 332 -67 714
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Quality Control - Analyses and Sample Location
Details of quality assurance/quality control procedures for sample analysis and drill hole survey methodology are reported in detail in the Canadian National Instrument 43-101 Standards of Disclosure for Mineral Projects ("NI 43-101") compliant Technical Report filed on SEDAR (www.sedar.com) on May 6 2005. All 2010 drill holes have had their down hole surveys completed by non-magnetic based instruments such as gyroscope or DeviFlex.
Qualified Persons
The program design, implementation, quality assurance/quality control and interpretation of the results are under the control of Northgate's geological staff, which includes a number of individuals who are qualified persons as defined under NI 43-101. Carl Edmunds, PGeo, Northgate's Exploration Manager, has reviewed the geologic contents of this release.
Note to Investors:
The terms "Qualified Person", "Mineral Reserve", "Proven Mineral Reserve", "Probable Mineral Reserve", "Mineral Resource", "Measured Mineral Resource", "Indicated Mineral Resource", and "Inferred Mineral Resource" used in this news release are defined in accordance with NI 43-101.
Northgate Minerals Corporation is a gold and copper producer with mining operations, development projects and exploration properties in Canada and Australia. Our vision is to be the leading intermediate gold producer by identifying, acquiring, developing and operating profitable, long-life mining properties.
Cautionary Note Regarding Forward-Looking Statements and Information:
This Northgate press release contains "forward-looking information", as such term is defined in applicable Canadian securities legislation and "forward-looking statements" within the meaning of the United States Private Securities Litigation Reform Act of 1995, concerning Northgate's future financial or operating performance and other statements that express management's expectations or estimates of future developments, circumstances or results. Generally, forward-looking information can be identified by the use of forward-looking terminology such as "expects", "believes", "anticipates", "budget", "scheduled", "estimates", "forecasts", "intends", "plans" and variations of such words and phrases, or by statements that certain actions, events or results "may", "will", "could", "would" or "might" "be taken", "occur" or "be achieved". Forward-looking information is based on a number of assumptions and estimates that, while considered reasonable by management based on the business and markets in which Northgate operates, are inherently subject to significant operational, economic and competitive uncertainties and contingencies. Northgate cautions that forward-looking information involves known and unknown risks, uncertainties and other factors that may cause Northgate's actual results, performance or achievements to be materially different from those expressed or implied by such information, including, but not limited to gold and copper price volatility; fluctuations in foreign exchange rates and interest rates; the impact of any hedging activities; discrepancies between actual and estimated production, between actual and estimated reserves and resources or between actual and estimated metallurgical recoveries; costs of production; capital expenditure requirements; the costs and timing of construction and development of new deposits; and the success of exploration and permitting activities. In addition, the factors described or referred to in the section entitled "Risk Factors" in Northgate's Annual Information Form for the year ended December 31, 2009 or under the heading "Risks and Uncertainties" in Northgate's 2009 Annual Report, both of which are available on the SEDAR website at www.sedar.com, should be reviewed in conjunction with the information found in this press release. Although Northgate has attempted to identify important factors that could cause actual results, performance or achievements to differ materially from those contained in forward-looking information, there can be other factors that cause results, performance or achievements not to be as anticipated, estimated or intended. There can be no assurance that such information will prove to be accurate or that management's expectations or estimates of future developments, circumstances or results will materialize. Accordingly, readers should not place undue reliance on forward-looking information. The forward-looking information in this press release is made as of the date of this press release, and Northgate disclaims any intention or obligation to update or revise such information, except as required by applicable law.
Cautionary Note to US Investors Regarding Mineral Reporting Standards:
Northgate prepares its disclosure in accordance with the requirements of securities laws in effect in Canada, which differ from the requirements of U.S. securities laws. Terms relating to mineral resources in this press release are defined in accordance with National Instrument 43-101-Standards of Disclosure for Mineral Projects under the guidelines set out in the Canadian Institute of Mining, Metallurgy, and Petroleum Standards on Mineral Resources and Mineral Reserves. The Securities and Exchange Commission (the "SEC") permits mining companies, in their filings with the SEC, to disclose only those mineral deposits that a company can economically and legally extract or produce. The Company uses certain terms, such as, "measured mineral resources" "indicated mineral resources", "inferred mineral resources" and "probable mineral reserves", that the SEC does not recognize (these terms may be used in this press release and are included in the Company's public filings which have been filed with securities commissions or similar authorities in Canada).
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