Great Plains Metals Corp. press release
Sienna Continues to Cut High Grades on Domo Area
TSXV - TSX Venture Exchange · Gold · Copper · Molybdenum · Rare Earth Elements · Uranium · Canada
CALGARY, Sept. 21 /CNW/ - Sienna Gold Inc. (SGP.V TSX Venture Exchange) announces the latest assay results from the Igor Concession. The Domo 4, 5 and 6 areas comprise approximately 228 meters of tunnels in mantos, feeder vein structures and breccias. The workings are located immediately to the northwest of the Domo 3 area which results were previously announced. These assays are from 249 samples taken from the three Domo workings. Based on exploration to date at the Igor property it is known that high concentrations of gold and silver are found in areas of tight anticlinal folding which is characteristic of the Domo zone. The Domo 4 results indicate that the small veinlets which occur throughout the Chimu - Santa sandstone transition zone host rocks are mineralized as is shown on the table below in which the manto results are lower than the host rock assays.
Latest Assay Results
The assay results have been divided into manto material and host rock material with average grades as shown.
<< Domo Weighted Maximum Weighted Maximum Weighted No. Area Average Au Average Ag Average Samples Au g/t Assay Ag g/t Assay Au + Ag g/t g/t Equivalent g/t(x)
Domo Manto 2.9 31.8 62 1,089 4.1 50 4 Host Rock 8.7 50.4 547 11,319 19.6 48 Total g/t 5.7 299 11.7 98
Domo Manto 16.6 71.8 75 477 18.1 21 5 Host Rock 8.0 52.1 48 318 9.0 62 Total g/t 10.0 54 11.1 83
Domo Manto 6.9 44.6 128 891 9.5 61 6 Host Rock 2.4 13.0 36 157 3.1 7 Total g/t 6.5 120 8.9 68 (x) This calculation assumes 100% recovery of both gold(US$550/oz) and silver (US$11/oz) >>
The Domo mineralization was emplaced by an epithermal, high sulfidation system which infilled numerous stockwork fractures and favourable bedding planes in transition zone sandstones along the axis of an anticlinal fault. This is confirmed by the presence of vuggy silica and hydrothermal breccias as well as late stage to post-mineralization pebble dykes. The three mantos are approximately 1 meter thick and formed in subparallel shale beds which trapped the hydrothermal fluids during mineralization sequences. The host rocks are composed of Chimu - Santa transition sandstones. The Domo zone extends over an area of approximately 700 meters by 100 meters and the samples were taken from channel rings every 6 meters along the tunnels as described below. These results suggest that the mineralization in the Domo manto region may be continuous between the Domo 1 and Domo 7 workings (previously reported) which are located towards the mapped extremities of the mineralized area. The assay results continue to indicate a polymetallic source for the mineralization. Many of the assays are anomalous in base metal elements with 18 of the results reporting lead values in excess of 1 percent. It is likely that the Domo mineralization is sourced from a deep porphyry-type intrusion, as per the geological model for the Igor Prospect. The porphyry intrusive model for the mineralization at the property was discussed in the company's August 16, 2006 press release.
Following is a listing of the most significant sample assays received:
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Sampling Methodology
The samples were taken by first exposing fresh rock in a 15 centimetre wide by 2 centimetre deep channel forming a ring in the walls and roof perpendicular to the axis of the tunnel and located every 6 meters along the tunnel. Continuous samples within specific lithologies were then chipped from the full width of the channel and collected for analysis. Where the rock was too hard for a full width sample, a narrower sample was taken from within the prepared channel zone ensuring that samples from the full width of the channel were obtained.
Assaying Methodology
The samples were analyzed by SGS Laboratories in Lima by inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis for silver and 33 other elements and a 30 gram fire assay technique for the gold analysis. Samples which exceeded the detection limits were re-assayed using a gravimetric fire assay technique. The specific procedures used by the lab can be found in the company's 43-101 report on the Igor Concession.
This press release has been reviewed and approved by Murray Lytle, P.Eng. who is the company's Qualified Person.
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.
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