Dia Bras intersects disseminated silver mineralization in new zone and approves aggressive exploration/development programme for its Cusi Silver Property

TSX Venture Exchange - DIB
Bolsa de Valores de Lima - DIB

TORONTO, March 30, 2012 /PRNewswire/ - Dia Bras Exploration Inc. (TSX-V:DIB) (BVL: DIB) ("Dia Bras" or the "Company") is pleased to announce that its board has approved a new exploration/development budget of $7 million primarily to drill the Promontorio, Santa Eduwiges and La India silver deposits in light of recent positive exploration results in these three areas.

Daniel Tellechea, President and CEO of the Company, commented: "There have been important new discoveries of disseminated silver mineralization with attractive silver grades, first in the Promontorio Area and more recently at the Santa Eduwiges area that warrant an aggressive drilling campaign to explore the potential extensions of these disseminated silver areas along the Cusi fault. The Promontorio and Santa Eduwiges areas are located 3 kilometres apart from each other but have very similar structural setting and mineralization".

Recent exploration discoveries:

Promontorio Area -
Recent mine development work confirms extensions and high grade nature of the silver disseminated area: During the past month, development on Level 9 has expanded into the disseminated zone where stockwork mineralization of quartz veinlets/stringers plus disseminated mineralization occurs.  On Frente 980, the last 15 m of drift into the known disseminated zone was sampled at 2 m intervals and averaged 350 g/t Ag.  This is very good grade development rock and reinforces the importance of the disseminated mineralization. Another 15 m of drifting is required to reach the Cusi fault, where historical mining has yielded high mined silver grades in excess of 1,000 g/t Ag.

Results from recent drill holes in the Promontorio area have been received and continue to expand the zone of disseminated mineralization in this area.  The results are shown in the table below:

The El Gallo vein is one of the multiple veins in the Promontorio area.

Santa Eduwiges Area: Discovered a disseminated silver zone, 3 km away from Promontorio's disseminated silver deposit: In the past four weeks, at Frente 410 the last 40 m of a drift in a variant of disseminated mineralization was sampled at 2 m intervals and averaged 220 g/t Ag.  Again, this is very good grade development rock.   At Frente 616, development has followed a vein 0.8 m in true width that has averaged 1,000 g/t Ag along a length of 40 m.  Once development is complete and stoping begins (on widths of 1.2 m), the grade of rock shipped from Santa Eduwiges will increase significantly.

In addition, stoping has commenced on second-order veins of the San Bartolo vein system with encouraging results.  The table below shows assay results from three stopes.  Because some samples have grades over 5,000 g/t Ag, the assays for the sample population from each stope has been capped at a standard limit, which is "the mean plus two standard deviations".

Moreover, drill hole 441 in the San Bartolo vein system of Santa Eduwiges cut a variant of disseminated-type mineralization and returned more high silver grades, as shown in the table below:

Drill hole 441 penetrated the footwall of the Cusi fault where the San Bartolo and Santa Marina veins intersect the fault.  This observation, combined with the excellent results in the same type of structural position at the Promontorio mine, presents the possibility that disseminated silver mineralization of significant width and grade will be discovered along the entire length of the Cusi fault.  The footwall of the Cusi fault from the San Juan mine to the Santa Eduwiges mine area, some 3 km, is now an important exploration area.

Cusi Program for 2012

The discovery of disseminated mineralization at Promontorio combined with the pilot-mining results from the Santa Eduwiges zone has resulted in a significantly increased budget for the Cusi property.  In addition to exploration of the Promontorio, Santa Eduwiges and La India Areas, Dia Bras has the following work planned in 2012:

• Promontorio Area: 1) The hoist capacity of the Promontorio shaft will be doubled to 200 tpd; 2) The ramp will be extended about 200 m to allow access to the disseminated zone on Level 5 and provide underground drilling stations that will test the zone at closer drill spacing than is practical from the surface; and, 3) De-watering of the Promontorio mine will continue with the objective of obtaining access to Level 10 and deeper levels.
• Santa Eduwiges Area: 1) De-watering of the mine below Level 10 will allow development of the San Bartolo and other veins to deeper levels; 2) development of the San Bartolo and other veins on Levels 8 and 10 will allow stoping of the high-grade veins.

The objective of this aggressive exploration and development programme at Cusi during 2012 is to significantly expand pilot mining operations and begin processing a combination of very good grade development rock and higher-grade veins.  The Company is confident that it will be able to achieve substantial increases in production in 2013 and 2014 as a result of this programme and aims to release updated production forecasts in the near future.

Cusi district overview

Dia Bras' Cusi property covers 118 km² and contains 12 historic mines (See Figure 1: Map of Cusi Property). High-grade silver ore was discovered at Cusi in 1666 and sporadic mining continued until the early 1940s.  Historic records indicate that some 120 million ounces of silver were produced from the area.

The Cusi Property is situated within the major north-northwest trending Sierra Madre Precious Metals Belt and mineralization in the property is generally vein-hosted, structurally-controlled epithermal silver-lead-zinc mineralization.  Recently, the Company has discovered significant high-grade disseminated mineralization that appears to be controlled by the Cusi Fault, which is high in silver and low in lead and zinc (see press releases of February 29, 2012 and November 15, 2011).  Veins hosting silver mineralization at Cusi strike to the north, northeast, east-northeast and east, and dip moderately-to-steeply east to southeast.  Sulfide-poor veins are generally higher in the vein systems and grade to sulfide-rich veins at depth.  The disseminated mineralization has been discovered adjacent to the NNW-trending Cusi fault.

Figure 1: Map of Cusi Property

Historic operators encountered great difficulties because of the remoteness of the camp.  Their operations were confined to smelting high-grade ore in small adobe smelters prior to the 1908 commissioning of the Chihuahua smelter, and then shipping high-grade ore by wagons to the smelter in Chihuahua City - a distance of 90 miles in a straight line but much greater by road.  These historic operators had a cut-off grade of approximately 1,000 g/t Ag (about 30 oz/ton), and this high cut-off grade resulted in the historic miners leaving behind rock that is very economic with modern mining practices.

Activities of Dia Bras

Dia Bras has concentrated its exploration, development and pilot-mining activity in the north-western part of the Cusi property because of the abundance of silver veins in the area and its easy access to the Company's 100% owned Malpaso mill, which is only 35 km from the operations area by flat roads and highways, most of which are paved.

During 2010 and 2011, Dia Bras pilot-mined and milled at Malpaso 55,892 tonnes of rock averaging 227.5 g/t silver, 0.88% Pb and 1.10% Zn.  The mill is a standard crushing and milling plant, with recovery of silver and lead by flotation, while silver and gold are recovered by vat leaching methods.  Recovery of silver averages 80-85% by the combined methods. 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.

Three areas within the Cusi project are being evaluated during 2012 and each area hosts multiple veins. These areas are:

Promontorio Area: This area hosts veins of several orientations and also hosts an area of disseminated mineralization.  The veins in this area include: Promontorio main vein, the alphabet veins that intersect the main vein (veins A-H), El Gallo and El Gallo Back veins, San Nicolas vein, San Ignacio vein, Veta Grande vein, and Veta del Contacto vein.

Exploration in this area includes surface drilling of the El Gallo, Veta del Contacto, Promontorio and alphabet veins, plus underground drilling from workings in the Promontorio mine (now being conducted on Level 5), and sampling and mapping of the underground workings down to Level 9.  Rock obtained from rehabilitation of workings and backfill of old veins as well as rock from development of new workings by Dia Bras are shipped to the Malpaso mill and processed.  This work has resulted in discovery of the silver-rich disseminated mineralization, for which the Company has great expectations regarding the tonnage potential of the project.

Santa Eduwiges Area: This area hosts the Santa Eduwiges vein, Santa Marina and Santa Marina El Alto veins, San Antonio and San Antonio Alto veins, San Bartolo veins, Mexicana vein, Tascates vein, Moctezuma vein, El Milagro vein, La Gloria vein, Milagro vein, La Bufita vein, San Nicolas extension vein, and the Soledad and Carta Blanca veins.

Pilot mining by the Company has been concentrated in this area due to its abundance of veins that intersect and diverge in a complex pattern.  Mining and development are now concentrated on the San Bartolo veins, between Levels 8 and 10, where the veins were not reached by historical workers and development of virgin, high-grades veins is in progress.  San Bartolo includes two parallel veins about 25 m apart that are connected by secondary cross veins.  De-watering continues to lower the water level in the workings below Level 10.  Development continues on several faces, and during the past month over 180 m of development has been done on six faces.

In the past four weeks, at Frente 410 the last 40 m of drift was sampled at 2 m intervals and averaged 220 g/t Ag.  Again, this is very good grade development rock.   At Frente 616, development has followed a vein 0.8 m in true width that has averaged 1,000 g/t Ag along a length of 40 m.  Once development is complete and mining begins (on widths of 1.2 m), the grade of rock shipped from Santa Eduwiges will increase significantly.

La India Area: This area hosts the following veins: La Durana, El Saturno, San Rafael, 20 de Noviembre, San Jose and La Candelaria vein.  This area is receiving renewed exploration interest as the results of mapping, sampling and drilling done during 2011 are compiled.  The Company intends to renew drilling on the San Jose and other veins during the second quarter of this year.

NI 43-101 Report

The Company intends to commission a NI 43-101 compliant resource calculation during the fourth quarter of this year.  The accelerated exploration and development work planned for the second and third quarters will provide a significantly expanded database that will allow calculation of resources in these three areas.

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) and is exploring in Mexico several precious metal targets such as La Sidra gold project at the Bolivar Property, the 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".

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.

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. 

SOURCE Dia Bras Exploration Inc.

Image with caption: "Figure 1: Map of Cusi Property (CNW Group/Dia Bras Exploration Inc.)". Image available at: http://photos.newswire.ca/images/download/20120330_C9474_PHOTO_EN_11781.jpg

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