CALGARY, Sept. 25 /CNW/ - Sienna Gold Inc. (SGP.V TSX Venture Exchange)
("Sienna" or the "Company") is pleased to present an update on the IGOR
project as reported by Dr. Warren Pratt.
The company today makes available a detailed geological report on the
IGOR concession by Dr. Pratt, the Company's principal geological consultant.
The report is not a 43-101 report and contains no new information on the
company's gold resources at Igor, which were the subject of an earlier 43-101
compliant report and news release.
This report summarizes exploration at Igor, controlled by the Company.
Igor is a gold and copper target in the Libertad province of northern Perz. Of
about 3000 geochemical surface samples gathered at Igor, over 45% contains
1 gram/tonne gold or more.
The report is based on field visits by the author to Igor, first as an
independent consultant and later as a Director. These visits emphasized the
potential for a porphyry system at Igor, responsible for driving the
polymetallic and gold (Au) mineralization of the whole district.
The report discusses 4 styles of mineralization at Igor. They comprise:
1) polymetallic, gold-rich mantos, which are best developed in the Domo Zone;
2) fault and breccia-related gold and polymetallics in the Tesoros zone;
3) oxidised gold in sandstone and porphyry at Callanquitas; and 4) a deeper
copper-gold porphyry, underlying the Igor Anticline. The porphyry was
intersected in drill holes that are over 2 km apart, giving the Igor porphyry
great size potential .
Drilling prior to November 2006 focused on the vein and manto gold
potential of Igor. Metallurgical work, comprising cyanide leach tests, was
carried out and 43-101 compliant resources were published in early 2008.
Subsequent drilling targeted near-surface oxidised gold and deep copper
porphyry targets, successfully identifying both. All drilling at Igor has been
with HQ and NQ diameter diamond drill core. A rigorous QC/QA procedure was
also put in place for work after November 2006, with blanks, standards and
check assays of both drill core and surface samples.
In his report, Dr. Pratt interprets the mantos in the anticline hinge and
the Tesoros Zone as mineralized structures on the periphery of, and above, a
porphyry copper-gold deposit. The high zinc/lead/silver/arsenic/antimony
values in the mantos are consistent with such a setting. Also, the strong
sericite, quartz and pyrite alteration of porphyritic dacites is interpreted
as hydrothermal alteration on the flanks of, or above, a porphyry system. This
interpretation is supported by the occurrence of pebble dykes.
The author draws attention to the similarities between Igor and the Cerro
Corona copper-gold porphyry mine (Gold Fields) and the El Galeno
copper/molybdenum/gold porphyry, recently sold to China Minmetals Non-Ferrous
Metals Co and Jiangxi Copper Company Ltd. Both of these projects are located
north of Igor, in Cajamarca.
El Galeno has Measured and Indicated Resources of 803 Mt at 0.63%
copper-equivalent. It is hosted by sills, dykes and stocks of Miocene porphyry
emplaced into Cretaceous sandstones and resembles a laccolith. It is important
to emphasize that the pattern of mineralization around complex intrusions,
such as El Galeno, differs significantly from the classic porphyry model of a
cylindrical stock (Lowell, and Guilbert, 1970). Likewise, Igor is probably
controlled by sills and dykes.
An oxidised gold resource of 19.4 Mt at a grade of 0.65 grams per tonne
of gold (plus a sulphide resource of 21 Mt at 0.93 grams per tonne of gold)
sits on one flank of the El Galeno porphyry and is hosted by Cretaceous
sandstones (Hilo Rico). Recent drilling at Igor has identified the potential
for a similar oxidised gold resource, hosted by Cretaceous sandstones and
porphyry intrusives in the Callanquitas area.
Significant lead/zinc/silver mineralization has been discovered recently
in the hanging wall of a thrust fault at Hilo Rico (El Galeno) and is an
extension to the oxidised gold resource. The high grade lead/zinc zone at
Tesoros, which post datesporphyry mineralization, may reflect a similar
mineralized extension at Igor.
The current drill program intends to demonstrate the copper/gold grades,
the size of the potential deposit, and how it is spatially located at the Igor
To review the entire report please visit our web site at
www.siennagold.com. It is also filed on SEDAR.
This press release has been reviewed and approved by Murray Lytle,
P.Eng., 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.
For further information:
For further information: John Rucci, President, (403) 508-2061 or by