CALGARY, Feb. 13 /CNW/ - Sienna Gold Inc. (SGP.V TSX Venture Exchange) announces the results of its resource estimation for the Domo and Tesoros mineralized zones at the Igor prospect. The basis for the estimate are the 9 holes drilled in the Domo zone, the 14 holes drilled in the Tesoros zone and the surface and underground samples taken from the many artisan workings in both zones. This estimate does not include any results from current drilling which is testing other targets. The NI 43-101 report for this resource estimate has been filed and is available on SEDAR.
The Company has also completed a preliminary metallurgical evaluation of the mineral resource and a number of different process strategies were evaluated. These results are also contained in the filed NI 43-101 report.
The results of the resource estimation are as follows:
Indicated Resource Estimate Summary
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Avg. Grades (gpt) Ounces
Tonnes ---------------------------------------------
Gold Silver Gold Silver Gold Equ.
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Tesoros Indicated 490,700 3.9 138 61,500 2,177,300 84,860
Domo Indicated 208,000 5.3 120 35,400 802,600 44,000
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Total Indicated 698,700 4.3 133 97,000 2,979,800 128,900
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Inferred Resource Estimate Summary
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Avg. Grades (gpt) Ounces
Tonnes ---------------------------------------------
Gold Silver Gold Silver Gold Equ.
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Tesoros Inferred 87,900 1.6 300 4,500 847,900 13,600
Domo Inferred 252,000 5.5 175 44,600 1,418,000 59,700
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Total Inferred 339,900 4.5 207 49,100 2,265,900 73,300
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Gold equivalent ounces = gold ounces + ((silver ounces x 50%
recovery) x $15/ounce / $700 per ounce)
The cut-off grade used in the analysis was 0.5 grams per tonne and the silver cut-off grade was 15 grams per tonne. An average specific gravity of 2.25 was used to calculate the tonnage of the mineralization. Laboratory testing to determine the specific gravity of a representative sampling of the cores will allow much of this indicated resource estimate to move to the measured category. A $485,000 exploration program has been proposed to move the inferred resources to the measured category as well.
Although this estimate can only be considered a geological resource it is worth pointing out that both mineralized zones outcrop at the surface and are covered by little or no overburden. All of the calculated resources are within 40 meters of the surface and would be easily accessible by open pit mining. When a feasibility study is completed which appropriately assesses both dilution and mining losses then the geological resources may pass to a mining reserve. It is emphasized that the preceding tables are an estimate of resources and not reserves.
Metallurgical recoveries of gold and silver using standard cyanide leach technology recovery were 77% and 52% respectively. A process using alkaline pre-activation at an elevated temperature achieved recoveries of 92% for gold and 94% for silver. More work will be done to choose the appropriate metallurgical process. For the purpose of this resource estimate an equivalent gold calculation has been made using the worst case metallurgical conditions.
The Company is currently drilling on the Igor concession and has completed three of 9 scheduled holes. The first was a 350 meter wildcat hole from the top of the Domo to understand the underlying geology. The second hole was a deepening of the lower a Tesoros hole (7B) (outside the calculated resource area) which was drilled originally in 2006. The first samples of this hole were delivered to ALS Chemex on February 8, 2008. The third hole is located in the Pampa de Igor between the Tesoros and Callanquitas zones. Over 100 meters of porphyry material was encountered beginning from surface and samples should be delivered to the lab by the third week in February. Dr. Warren Pratt will be visiting the project on February 15, 2008 and a decision on additional drill holes for the Pampa de Igor zone will be taken then. For the moment the drill has been moved to the Callanquitas zone where drilling commenced February 8, 2008.
The Callanquitas zone is considered the most prospective area of this drill program and it is anticipated that a gold/silver breccia zone will be encountered. The Company's geologic model also places the bulk of the mineralized porphyry in this area and the current drill program will either confirm or alter this view.
This press release has been reviewed and approved by Randy Henkle, P.Geol. and Murray Lytle, P.Eng. who are the company's Qualified Persons for this resource estimate.
The TSX Venture Exchange has neither approved nor disapproved of the
information contained herein.
Statements in this press release regarding the Company's business which are not historical facts are "forward-looking statements" that involve risks and uncertainties, such as estimates and statements that describe the Company's future plans, objectives or goals, including words to the effect that the Company or management expects a stated condition or result to occur. Since forward-looking statements address future events and conditions, by their very nature, they involve inherent risks and uncertainties. Actual results in each case could differ materially from those currently anticipated in such statements.
ContactsJohn RucciPresident
(403) 508-2061 or by e-mail rucci@telus.net
