Dia Bras Drilling Programme Discovers More Wide Mineralized Zones With High Grades of Silver at Its Promontorio Mine, Cusi Property
TORONTO, ONTARIO -- (Marketwire) -- 02/29/12 -- Dia Bras Exploration Inc. (TSX VENTURE: DIB) ('Dia Bras' or the 'Company') is pleased to report that continued drilling from the surface at its Promontorio mine ('Figure 1: Cusi Project Map View') has discovered more wide zones of disseminated silver mineralization. Additionally, the Company has provided an update on its pilot mining operations at the Cusi property for December 2011 and January 2012.
The Company completed five new drill holes in the disseminated zone of the Promontorio mine and is planning an additional 13 holes, all of which will be drilled from underground workings. These holes are also in a zone of silicified rhyodacite that contains disseminated argentite and narrow veinlets of argentite, as described in the press release of September 14, 2011. It is a sulphide-poor interval with minor quartz veinlets and is a type of mineralization at Cusi that indicates the potential for underground bulk mining.
'We continue to discover broad zones of silver mineralization, as indicated especially by drill hole 151 that cut 109 m of 157 g/t silver.' stated Daniel Tellechea, President and CEO of Dia Bras Exploration. 'These results combined with our previous results confirm the extensions of a high-grade disseminated silver deposit which should justify a significant increase in silver production as we expand development and mining at the Cusi property.'
The Figure 1: Cusi Project Map View is available at the following address: http://media3.marketwire.com/docs/dia-fig1.jpg.
Significant results from the five holes plus three holes from 2007 are presented in 'Table 1: Summary of Cusi Drill Results', below (see also 'Figure 2: Promontorio Area 2N Cross Section').
Table 1: Summary of Cusi Drill Results
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Hole Number From (m) To (m) Core Au g/t Ag g/t Pb % Zn %
Length
(m)
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DC07B101B(i) 98.0 113.0 15.0 0.013 1,021.3 0.19 0.08
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And 116.0 119.0 3.0 0.035 427.3 0.64 0.06
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And 147.5 150.5 3.0 0.015 199.0 0.24 0.45
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DC07B132(ii) 162.5 174.5 12.0 0.161 333.5 0.17 0.19
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DC07B151(iii) 113.0 222.0 109.0 0.022 157.3 0.11 0.14
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Incl. 153.0 159.0 6.0 0.052 693.0 0.15 0.19
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Incl. 181.5 196.5 15.0 0.075 527.7 0.21 0.19
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And 232.1 229.0 16.9 0.024 254.2 0.49 0.46
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Incl. 241.7 246.0 4.3 0.071 847.5 1.37 1.13
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DC11B380 102.4 191.15 88.75 0.007 55.4 0.08 0.12
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Incl. 102.4 111.5 9.1 0.006 138.5 0.15 0.17
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Incl. 153.4 156.75 3.35 0.016 191.0 0.18 0.16
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Incl. 183.5 191.15 7.65 0.017 94.9 0.11 0.14
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DC11B384 225.9 242.75 16.85 0.192 200.6 1.84 2.46
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DC11B390 99.85 166.8 66.95 0.014 114.8 0.08 0.16
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Incl. 150.3 157.05 6.75 0.031 635.4 0.26 0.46
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DC11B395 124.5 135.7 11.2 0.007 71.9 0.05 0.11
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And 335.8 343.7 7.9 0.75 227.5 0.88 1.36
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DC11B405 132.8 144.3 11.5 0.007 58.4 0.06 0.13
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(i) Partial results published June 19, 2007
(ii) Partial results published December 13, 2007
(iii) Partial results published January 30, 2008
Note: Lower grade portions of drill results previously released were not included in the original release but the Company now believes these portions are potentially mineable as part of an underground, bulk mining programme. Furthermore, the true widths are not known because the Company requires more drill holes in this broad zone of disseminated silver mineralization before determining them. The Company's geologists infer, however, that given their current understanding of the zone, these core widths are probably close to true widths.
The Figure 2: Promontorio Area 2N Cross Section is available at the following address: http://media3.marketwire.com/docs/dia-fig2.jpg.
Cusi Pilot Mining Update:
As part of its pilot-mining programme, the Company has been sending mineralized rock from the Santa Eduwiges mine and, more recently, from its Promontorio mine to its 100% owned Malpaso mill, which is located only 35 km by road from the mine. Pilot mining provides important information on metallurgy, recovery rates, mining and milling costs, etc., that are essential in determining the economic viability of a project.
During the month of December, 2011, for example, the Malpaso mill processed 2,953 tonnes of rock averaging 203 g/t silver ('Ag'), 0.92% lead ('Pb') and 0.88% zinc ('Zn'), which illustrates the silver-rich nature of the Cusi mineralization. Recovery of silver averages 80-85% due to a combination of flotation and cyanide vat-leach methods. The Company produces silver-rich lead concentrate and silver dore.
During January, 2012, 300 tonnes of rock averaging 200 g/t Ag from Level 9 of the Promontorio disseminated zone were delivered to the Malpaso mill. The Company is programming increased mining of the silver-rich Promontorio disseminated zone for the second quarter of this year.
Method of Analysis
Samples were prepared at the ALS Chemex lab facility in Chihuahua, Mexico, and analyzed by ICP and AA methods at their facilities in Vancouver, Canada. Diamond drill samples sent for analysis consisted of half NQ-size and BQ-size diamond core split on site, prepared by the ALS Chemex sample preparation laboratory in Chihuahua, Mexico, and assayed for Au by 50 g fire assay with AA finish, and for Ag by AA on 50 g split sample at the ALS Chemex North Vancouver Laboratory. Assays for Pb, Zn and Cu are analyzed by Induction Coupled Plasma (ICP) at ALS Chemex.
Quality Control
The quality assurance-quality control (QA-QC) of Dia Bras has been described in detail in both RPA's NI 43-101 reports of December 2006 at Cusi and October 2005 for Bolivar.
The technical content of this news release has been approved by Thomas L. Robyn, Ph.D., CPG, RPG, a Qualified Person as defined in NI 43-101.
About Dia Bras
Dia Bras Exploration is a Canadian exploration & mining company focused on precious and base metals in Chihuahua State, other areas of northern Mexico, and most recently at its Yauricocha silver-lead-zinc-copper-gold mine in Peru. The Company is accelerating exploration at the Yauricocha property as well as pursuing the development and exploration of its most advanced Mexican assets - the Bolivar Property (copper-zinc-silver) and the Cusi Property (silver-lead) and is exploring in Mexico several precious metal targets such as La Sidra gold project at the Bolivar Property, Las Coloradas silver project at Melchor Ocampo (Zacatecas State), the Bacerac silver project (Sonora State), and the La Verde gold project at the Batopilas Property (Chihuahua State). Dia Bras is also exploring base metal projects in Mexico such as the Corralitos intrusion-hosted molybdenum deposit (Chihuahua State).
The Company's shares trade on the TSX Venture Exchange under the symbol 'DIB'. For further information on Dia Bras Exploration Inc. visit www.diabras.com .
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.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release.
Contacts:
Dia Bras Exploration Inc.
Daniel Tellechea
President & CEO
1 (866) 493-9646
Dia Bras Exploration Inc.
Matt Morrish
Director, Investor Relations
1 (866) 493-9646
www.diabras.com