Dia Bras Exploration Inc.

Dia Bras Exploration Inc.

November 01, 2005 11:29 ET

Dia Bras Receives First NI 43-101 Report on the Bolivar Cu-Zn Project, Resource Evaluation Moves Into Measured and Indicated

MONTREAL, QUEBEC--(CCNMatthews - Nov. 1, 2005) - Dia Bras Exploration (TSX VENTURE:DIB) is pleased to announce Mineral Resources for the Bolivar deposit. The Company has received a technical report for the Bolivar Cu-Zn Project, titled "Technical Report on the Bolivar Cu-Zn Project, State of Chihuahua, Mexico", dated October 25, 2005. The report was prepared by Hryar Agnerian, M.Sc. (Applied), P.Geo, from Roscoe Postle Associates (RPA) independent Qualified Persons under NI 43-101 standards.

The complete technical report is available under Dia Bras Exploration on the SEDAR website at www.sedar.com and on Dia Bras' website at www.diabras.com.

The Mineral Resources of the Bolivar deposit are contained predominantly within two mineralized zones, the north trending Rosario Trend and the east trending Fernandez Trend. Both of these trends have been partly outlined by diamond drill holes as well as by underground development.

RPA has estimated the Mineral Resources of the Bolivar deposit using the database from the 133 drill holes which Dia Bras has provided. These drill holes have been completed during 2004.

The Mineral Resources estimate for Bolivar deposit used a cut-off grade based on the approximate average prices for copper and zinc, production cost and expected recovery in the resource model. RPA has used an over-all recovery of approximately 75% for copper and 80% for zinc. This is based on the five month production record (February to June 2005) at the Malpaso mill. RPA has used the production costs as determined by Dia Bras for underground mining at Bolivar. These costs are reported to be similar to other copper-zinc operations of similar scale in Mexico. At a copper price of around US$1.60 /lb. Cu and US$0.58 /lb. Zn, the cut-off grade for the Bolivar deposit resource estimate is calculated as 1.0% Cu and 6% Zn (3.4% Cu Equivalent). RPA recommends that this cut-off grade be used to report Mineral Resources. The Mineral Resources on the Bolivar Deposit are summarized in the following table:

Bolivar Deposit
Trend Category Tonnes % Cu % Zn g/t Ag g/t Au
Rosario Measured 26,700 1.34 7.81 31.15 0.08
Rosario Indicated 325,000 2.48 9.48 49.65 0.25
Rosario Inferred 17,000 2.42 10.27 15.96 0.03
Fernandez Indicated 24,900 3.18 1.78 211.67 2.69
Subtotal Indicated 359,900 2.61 8.79 63.46 0.41
Subtotal Inferred 17,000 2.44 10.26 15.83 0.03

1. CIM Definitions were followed for the resource estimate.
2. Mineral Resources are estimated at a cutoff grade of 1% Cu and 6%
Zn, an average copper price of US$1.60 per lb and an average zinc
price of US$0.58 per lb, and a minimum width of 2.4 m for a
mineralized zone.
3. Density of mineralized rock is 3.42 t/m3

Exploration Potential

The Bolivar Mine is a past producer of copper-zinc and on-going exploration by Dia Bras continues to extend known zones of copper, zinc, silver and gold mineralization along strike of the Rosario Trend as well as the Fernandez Trend, near the Bolivar Adit. Recent drilling and prospecting around the Bolivar mine area have discovered new target areas within zones of skarn-type hydrothermal alteration. Such a new zone located 125 metres west of the Bolivar shaft returned 1.34% Cu, 1.16% Zn, 47 g/t Ag over 26 meters and 0,78% Cu, 0.44% Zn and 17 g/t Ag over 34 meters in DIA-41 and DIA-44 respectively. A similar zone, cut by DIA-127 and DIA-128 collared 600 meters south of the shaft, returned 1.14% Cu, 0.06% Zn, 61.35 g/t Ag and 3.08 g/t Au over 4 meters.

Rosoe Postel & Associates recommends a systematic exploration program including drilling as well as a scoping study to assess the economic potential of the Bolivar deposit. Drill results will be issued as they become available.

Dia Bras has already initiated such a program and has three drill rigs, two on surface and one underground, testing all the mineralized structures continuously.

About Dia Bras

Dia Bras is a Canadian mining and exploration Company focused on precious and base metals in the State of Chihuahua, northern Mexico. The Company continues exploration and the active development of its two key projects - Bolivar and Promontorio - in the world-renowned Sierra Madre mineral belt. The Company trades on the TSX Venture Exchange, under the symbol "DIB".

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Forward-looking statements: Except for statements of historical fact, all statements in this news release, without limitation, regarding new projects, acquisitions, future plans and objectives are forward-looking statements which involve risks and uncertainties. There can be no assurance that such statements will prove to be accurate; actual results and future events could differ materially from those anticipated in such statements.

The TSX Venture Exchange does not accept responsibility for the adequacy or accuracy of this press release.

Contact Information

  • Dia Bras Exploration
    Rejean Gosselin
    (514) 866-6001 ext. 241
    CHF Investor Relations
    Linda Armstrong
    Vice President
    (416) 868-1079, ext 229