Atna Announces Significant Increase in Gold Resource at Pinson

GOLDEN, Colo., Feb. 6, 2012 /CNW/ - Atna Resources Ltd. ("Atna" or the "Company") (TSX: ATN / OTCBB: ATNAF) is pleased to report the newly updated resource estimate at the Pinson Mine near Winnemucca, Nevada. This estimate incorporates all available data relating to Atna's property position at Pinson, including:

  • All Pinson Mining Company's drill results generated between 2006 and 2008.
  • Open pit drill information not previously incorporated in NI 43-101 Technical Studies.
  • All prior data relating to the high grade underground mineralization at Pinson.

This study adds a significant open pit mineral resource to the already extensive high-grade underground mineral resource previously reported for Pinson. Total resource by underground and open pit scenarios are as follows:



Resource Summary (imperial)

Resource Summary (metric)

Underground

Tons

(x 1,000)

oz/ton Au

Contained

Ounces Gold

Tonnes

(x 1,000)

g/t Au

Measured

1,619.1

0.355

575,000

1,468.8

12.18

Indicated

1,300.7

0.383

498,000

1,180.0

13.13

M & I-Total

2,919.8

0.368

1,073,000

2,648.8

12.60

Inferred

2,236.2

0.378

845,900

2,028.6

12.97







Open Pit

Resource Summary (imperial)

Resource Summary (metric)

Measured

21,158.9

0.035

732,000

19,195.0

1.19

Indicated

4,307.4

0.058

249,600

3,907.6

1.04

M & I-Total

25,466.3

0.039

981,700

23,102.6

1.32

Inferred

824.4

0.034

28,300

747.9

1.18

Imperial cut-off = 0.20 oz/ton Au Underground & 0.01 oz/ton Au Open Pit

Metric cut-off = 6.34 g/tonne Au Underground, 0.34 g/tonne Au Open Pit

Rounding may cause columns to not add or multiply precisely




Further detail of the mineral resource estimates are listed by zone and cutoff grade in the appended tables.

"This study demonstrates previously known high-grade underground mineral potential at Pinson and adds a significant open-pit mineral resource. We believe Pinson continues to have further exploration opportunity and are excited by the prospect of Pinson becoming Atna's major gold producer," states James Hesketh, President & CEO.

Atna plans to start commercial underground mine production in the fourth quarter 2012. Underground mine design work is presently underway utilizing the resource model developed in this study. The contract miner at Pinson is currently driving a secondary access and Atna anticipates the mining of bulk metallurgical samples over the next quarter. Atna will begin feasibility study work to develop the open pit potential at Pinson in the coming months as underground production ramps up.

Combined measured and indicated resources estimates for the high grade underground zones were largely unchanged from prior estimates released by Atna in 2007, although inferred resources were reduced. This was due to factors that included the use of more conservative interpolation parameters based on a larger data set, the inclusion of additional data which changed geologic interpretations in local areas, and interaction with open-pit resource estimation.

To estimate the mineral resource; geologic, structural and mineral domains were constructed using available geologic data. This information was modeled using geostatistical methods to estimate gold grades and develop a three-dimensional block model. Structure and stratigraphy of the Pinson area was defined by combining subsurface data with surface geology to create three dimensional structural and stratigraphic models. Each of the CX Fault, CX-West Fault, Range Front Fault, Adams Peak Shear Zone, Otto Stope, Linehole North Fault, SOS Fault, SOS Dike, SOS Cross Fault and two CX Fault Splays, and the South and Mag pit areas were individually modeled. The Block model was divided into five statistically related zones to accommodate statistical search parameters appropriate for individual mineral styles. These were reported as the Mag and South pit zones, the Ogee/CX-West, Range Front and CX zones.

In order to define open-pit versus underground resources, the Mag and South pit resource zones were defined utilizing a pit optimizing tool, pit slopes of 45 degrees and costs based on Briggs Mine actual costs that assume heap leach gold recovery. Gold recovery was guided by previous heap leach operating experience at Pinson, where gold recovery was defined by the ratio of cyanide soluble gold assay to total gold assay.

Pinson is presently permitted for underground mining under a small miner's permit. Applications will be made in the near future to administratively amend this permit to allow full scale underground operations. High-grade ore mined at Pinson will be transported to nearby third party plants for processing. Additional permitting, which may require the completion of an environmental impact study, will be required to support open pit mining and heap leach recovery operations at Pinson. Pinson historically produced almost one million ounces of gold through open pit mining and heap leach and oxide mill recovery.

The resource estimate was prepared for Atna by Gustavson Associates, LLC of Colorado, a leading global mining consulting firm consisting of geologists and engineers, under the supervision of Donald E. Hulse, P.E. a Qualified Person as defined in NI 43-101.

This press release was prepared under the supervision and review of William Stanley, V.P. Exploration of Atna, a Registered Member of the Society for Mining, Metallurgy, and Exploration, a Licensed Geologist and Qualified Person, as defined in NI 43-101, who has verified the authenticity and validity of the technical information contained within this news release.

For additional information on Atna Resources and the Pinson Mine, please visit our website at www.atna.com.

This press release contains certain "forward-looking statements," as defined in the United States Private Securities Litigation Reform Act of 1995, and within the meaning of Canadian securities legislation relating to potential mineral resource, reserve or production at the Pinson Mine. Forward-looking statements are statements that are not historical fact. They are based on the beliefs, estimates and opinions of the Company's management on the date the statements are made and they involve a number of risks and uncertainties. Consequently, there can be no assurances that such statements will prove to be accurate and actual results and future events could differ materially from those anticipated in such statements. The Company undertakes no obligation to update these forward-looking statements if management's beliefs, estimates or opinions, or other factors, should change, unless required by law. Factors that could cause future results to differ materially from those anticipated in these forward-looking statements include: gold deposit modeling, development and future production at the Pinson Mine, the Company might encounter problems such as the significant depreciation of metals prices; accidents and other risks associated with mine development and production operations; the risk that the Company will encounter unanticipated geological factors; the Company's need for and ability to obtain additional financing; the possibility that the Company may not be able to secure permitting and other governmental clearances necessary to carry out the Company's exploration and development programs; and the other risk factors discussed in greater detail in the Company's various filings on SEDAR (www.sedar.com) with Canadian securities regulators and its filings with the U.S. Securities and Exchange Commission, including the Company's 2010 Form 20-F dated March 23, 2011.

Cautionary Note to U.S. Investors --- The United States Securities and Exchange Commission permits U.S. mining companies, in their filings with the SEC, to disclose only those mineral deposits that a company can economically and legally extract or produce. We use certain terms in this report, such as "measured," "indicated," "inferred," and "resources," that the SEC guidelines strictly prohibit U.S. registered companies from including in their filings with the SEC.

FOR FURTHER INFORMATION, CONTACT:

James Hesketh, President and CEO - (303) 278-8464
Valerie Kimball, Investor Relations - toll free (877) 692-8182
www.atna.com


Underground Mineral Resources (Imperial)

Cutoff

Measured

Indicated

Measured + Indicated

Inferred

Gold

Tons

Gold

Ounces

Tons

Gold

Ounces

Tons

Gold

Ounces

Tons

Gold

Ounces

opt


opt

Au


opt

Au


opt

Au


opt

Au

0.100

3,037,200

0.257

781,700

2,516,000

0.266

668,400

5,553,300

0.261

1,450,100

4,204,900

0.269

1,129,500

0.150

2,244,000

0.304

683,100

1,719,700

0.332

570,900

3,963,700

0.316

1,254,000

3,013,500

0.326

982,800

0.200

1,619,100

0.355

575,000

1,300,700

0.383

498,000

2,919,800

0.368

1,073,000

2,236,200

0.378

845,900

0.250

1,171,900

0.405

474,900

934,300

0.444

415,000

2,106,200

0.423

889,900

1,722,800

0.424

730,600

0.300

828,700

0.459

380,700

606,600

0.534

324,000

1,435,300

0.491

704,700

1,253,500

0.480

601,200

0.500

206,100

0.715

147,300

291,500

0.701

204,200

497,600

0.706

351,600

481,600

0.617

297,100

Underground Mineral Resources (Metric)

Cutoff

Measured

Indicated

Measured + Indicated

Inferred

Gold

Tonnes

Gold

Ounces

Tonnes

Gold

Ounces

Tonnes

Gold

Ounces

Tonnes

Gold

Ounces

g/t


g/t

Au


g/t

Au


g/t

Au


g/t

Au

3.43

2,755,300

8.82

781,700

2,282,500

9.11

668,400

5,037,800

8.95

1,450,100

3,814,600

9.21

1,129,500

5.14

2,035,700

10.44

683,100

1,560,100

11.38

570,900

3,595,800

10.85

1,254,000

2,733,800

11.18

982,800

6.86

1,468,800

12.18

575,000

1,180,000

13.13

498,000

2,648,800

12.60

1,073,000

2,028,600

12.97

845,900

8.57

1,063,100

13.89

474,900

847,500

15.23

415,000

1,910,700

14.49

889,900

1,562,900

14.54

730,600

10.29

751,800

15.75

380,700

550,300

18.31

324,000

1,302,100

16.83

704,700

1,137,100

16.44

601,200

17.14

187,000

24.51

147,300

264,500

24.02

204,200

451,400

24.22

351,600

436,900

21.15

297,100





Underground Mineral Resource by Area, 0.20 oz/ton Au cut-off (Imperial)


Measured

Indicated

Measured + Indicated


Inferred


Zone

Tons

Gold

Contained

Tons

Gold

Contained

Tons

Gold

Contained

Tons

Gold

Contained



opt

ounces Au


opt

ounces Au


opt

ounces Au


opt

ounces Au

Ogee/CX-West

398,000

0.405

161,100

385,700

0.402

155,200

783,700

0.404

316,300

433,700

0.324

140,400

Range Front

459,700

0.325

149,300

363,500

0.345

125,400

823,100

0.334

274,700

447,200

0.319

142,800

Adams Peak

415,100

0.341

141,600

129,200

0.287

37,100

544,300

0.328

178,700

79,100

0.292

23,100

Otto Stope

29,700

0.523

15,500

122,800

0.400

49,100

152,400

0.424

64,600

290,500

0.361

105,000

Linehole North

2,200

0.245

500

121,200

0.633

76,700

123,400

0.626

77,200

760,400

0.489

372,000

CX Fault & splays

314,400

0.340

107,000

178,500

0.306

54,600

492,900

0.328

161,600

225,400

0.278

62,600

Summary

1,619,100

0.355

575,000

1,300,700

0.383

498,000

2,919,800

0.368

1,073,000

2,236,200

0.378

845,900














Underground Mineral Resource by Area, 6.86 g/t Au cut-off (Metric)


Measured

Indicated

Measured + Indicated

Inferred

Zone

Tonnes

Gold

Contained

Tonnes

Gold

Contained

Tonnes

Gold

Contained

Tonnes

Gold

Contained



g/t

ounces Au


g/t

ounces Au


g/t

ounces Au


g/t

ounces Au

Ogee/CX-West

361,100

13.88

161,100

349,900

13.79

155,200

711,000

13.84

316,300

393,400

11.10

140,400

Range Front

417,000

11.13

149,300

329,700

11.83

125,400

746,700

11.44

274,700

405,700

10.95

142,800

Adams Peak

376,600

11.69

141,600

117,200

9.84

37,100

493,800

11.25

178,700

71,700

10.02

23,100

Otto Stope

26,900

17.93

15,500

111,400

13.72

49,100

138,300

14.54

64,600

263,500

12.39

105,000

Linehole North

2,000

8.40

500

109,900

21.70

76,700

111,900

21.46

77,200

689,800

16.77

372,000

CX Fault & splays

285,200

11.67

107,000

161,900

10.48

54,600

447,200

11.24

161,600

204,500

9.52

62,600

Summary

1,468,800

12.18

575,000

1,180,000

13.13

498,000

2,648,800

12.60

1,073,000

2,028,600

12.97

845,900





Open Pit Mineral Resources (Imperial)










Cutoff


Measured



Indicated



Measured + Indicated


Inferred


Gold

Tons

Gold

Contained

Tons

Gold

Contained

Tons

Gold

Contained

Tons

Gold

Contained

opt


opt

ounces Au


opt

ounces Au


opt

ounces Au


opt

ounces Au

0.005

26,291,100

0.029

770,700

5,123,000

0.050

255,600

31,414,100

0.033

1,026,300

1,035,200

0.029

29,900

0.010

21,158,900

0.035

732,000

4,307,400

0.058

249,600

25,466,300

0.039

981,700

824,400

0.034

28,300

0.015

16,999,400

0.040

681,000

3,652,700

0.066

241,500

20,652,100

0.045

922,600

659,000

0.040

26,200

0.020

13,988,700

0.045

628,500

3,198,500

0.073

233,800

17,187,300

0.050

862,200

531,600

0.045

24,100

0.025

11,474,200

0.050

572,200

2,837,000

0.080

225,700

14,311,200

0.056

797,900

426,800

0.051

21,700

0.030

9,338,900

0.055

513,500

2,495,100

0.087

216,200

11,834,000

0.062

729,700

356,800

0.055

19,800














Open Pit Mineral Resources (Metric)

Cutoff

Measured

Indicated

Measured + Indicated

Inferred

Gold

Tonnes

Gold

Contained

Tonnes

Gold

Contained

Tonnes

Gold

Contained

Tonnes

Gold

Contained

g/t


g/t

ounces Au


g/t

ounces Au


g/t

ounces Au


g/t

ounces Au

0.17

23,850,900

1.01

770,700

4,647,500

1.71

255,600

28,498,400

1.12

1,026,300

939,100

0.99

29,900

0.34

19,195,000

1.19

732,000

3,907,600

1.99

249,600

23,102,600

1.32

981,700

747,900

1.18

28,300

0.51

15,421,600

1.37

681,000

3,313,700

2.27

241,500

18,735,300

1.53

922,600

597,800

1.37

26,200

0.69

12,690,300

1.54

628,500

2,901,700

2.51

233,800

15,592,000

1.72

862,200

482,200

1.55

24,100

0.86

10,409,200

1.71

572,200

2,573,600

2.73

225,700

12,982,900

1.91

797,900

387,200

1.74

21,700

1.03

8,472,100

1.89

513,500

2,263,500

2.97

216,200

10,735,600

2.11

729,700

323,700

1.90

19,800





Open Pit Mineral Resource by Area, 0.010 oz/ton Au cut-off (Imperial)


Measured

Indicated

Measured + Indicated

Inferred

Zone

Tons

Gold

Contained

Tons

Gold

Contained

Tons

Gold

Contained

Tons

Gold

Contained



opt

ounces Au


opt

ounces Au


opt

ounces Au


opt

ounces Au

Mag Pit

20,631,000

0.034

711,100

2,703,800

0.074

200,900

23,334,800

0.039

912,000

533,000

0.038

20,300

South Zone

527,900

0.040

21,000

1,603,600

0.030

48,800

2,131,500

0.033

69,700

291,400

0.028

8,000

Summary

21,158,900

0.035

732,000

4,307,400

0.058

249,600

25,466,300

0.039

981,700

824,400

0.034

28,300














Open Pit Mineral Resource by Area, 0.34 g/t Au cut-off (Metric)


Measured

Indicated

Measured + Indicated

Inferred

Zone

Tonnes

Gold

Contained

Tonnes

Gold

Contained

Tonnes

Gold

Contained

Tonnes

Gold

Contained



g/t

ounces Au


g/t

ounces Au


g/t

ounces Au


g/t

ounces Au

Mag Pit

18,716,100

1.18

711,100

2,452,900

2.55

200,900

21,169,000

1.34

912,000

483,500

1.31

20,300

South Zone

478,900

1.36

21,000

1,454,800

1.04

48,800

1,933,600

1.12

69,700

264,400

0.94

8,000

Summary

19,195,000

1.19

732,000

3,907,600

1.99

249,600

23,102,600

1.32

981,700

747,900

1.18

28,300




SOURCE Atna Resources Ltd.

For further information:

http://www.atna.com

Profil de l'entreprise

Atna Resources Ltd.

Renseignements sur cet organisme


FORFAITS PERSONNALISÉS

Jetez un coup d’œil sur nos forfaits personnalisés ou créez le vôtre selon vos besoins de communication particuliers.

Commencez dès aujourd'hui .

ADHÉSION À CNW

Remplissez un formulaire d'adhésion à CNW ou communiquez avec nous au 1-877-269-7890.

RENSEIGNEZ-VOUS SUR LES SERVICES DE CNW

Demandez plus d'informations sur les produits et services de CNW ou communiquez avec nous au 1‑877-269-7890.