Dia Bras Identifies Significant Target Tonnage below the Central Mine Area at Yauricocha
TSX Venture Exchange - DIB
Bolsa de Valores de Lima - DIB
TORONTO, Sept. 12, 2012 /PRNewswire/ - Dia Bras Exploration Inc. (TSX-V:DIB) (BVL: DIB) ("Dia Bras" or the "Company") is pleased to announce a target for further exploration in the Central Mine Area. The potential of the Central Mine Area below the mine workings and areas drilled under the workings is approximately 5-6 million tonnes, roughly averaging 90-110 g/t Ag, 2-3% Pb, 0.5-1.0% Cu, 2-3% Zn and 0.6-1.0 g/t Au. This target is in addition to the resources and reserves announced September 6, 2012.
Daniel Tellechea , President and CEO of Dia Bras , commented: "Our geologists have identified extensive down-dip potential at the Yauricocha mine, based on their intimate knowledge of the deposit and its mineral deposit type. We have developed a new drilling station and intend to drill and explore this target area under the Central Mine Area, specifically the down-dip extensions of the Cuye, Catas, Antacaca, Rosaura and Antacaca Sur ore bodies. Our objective is to demonstrate that these ore bodies continue to depth and add resources to the deposits. With the planned drilling program, we expect to be able to add resource tonnes on an inferred basis by Q1 2013."
The identification of this exploration target is based solely on the Company's understanding of the geology of the deposit, the staff's experience from several decades of mining of the ore bodies, the mineral deposit type itself as well as confidence that the ore zones are not truncated at depth by faults or other factors. Thomas L. Robyn , Ph.D., CPG, RPG, of Dia Bras , has supported geologic indications to make such assumptions.
Ore bodies in the Central Mine Area have been continuously mined since 1961 and have been drilled for vertical distances of up to 800 meters, which potentially signifies a continuous mineralized system occurs in the area. Comparison of Yauricocha with other well-studied and documented deposits of its type (high-temperature carbonate replacement) indicates that that mineralization should continue to depth for a significant distance.
These findings are based on Yauricocha's similarity to other deposits of its type, the extensive history of the mine, absence of structural complexities, and the high quality of work done by the mine's staff, all of which allow a certain confidence level regarding continuity of mineralization.
The initial conclusions by the Company's geologists are conceptual in nature and based on projections of ore bodies defined by underground sampling and drilling within and 200-300 m below the deepest mine level. As a result, the exploration target is modeled on the widths, strike lengths and grades of the ore bodies immediately above the target. The confidence level of the projection decreases as the projection of geologic inference goes further from areas of factual data.
A preliminary internal evaluation supports the further analysis of the Central Mine Area below the mine workings and areas drilled under the workings, and above Level 1420. The potential of the Central Mine Area below the mine workings and areas drilled under the workings is approximately 5-6 million tonnes, roughly averaging 90-110 g/t Ag, 2-3% Pb, 0.5-1.0% Cu, 2-3% Zn and 0.6-1.0 g/t Au.
The potential quantity and grades of the exploration target are conceptual in nature as there has been insufficient exploration to define a mineral resource below Level 1220, and it is uncertain if further exploration will result in discovery of a mineral resource at greater depth.
This potential will be explored during the next few months by drilling from a previously-used drilling station as well as a new underground chamber constructed specifically to test the down-dip potential of the ore bodies. The attached figure shows the planned piercing points (black dots) in the target zone below the known mineralization. The objective of the drilling is to demonstrate continuation of mineralization to depth and to add resources to those currently determined (see press release of September 6, 2012).
Basis for Results
Yauricocha is a mineral deposit of the high-temperature, Carbonate Replacement Deposit (CRD) type, also known as Leadville Type Mineralization (LTM). LTM deposits are high temperature (>200° C) carbonate-hosted Ag-Pb-Zn deposits that result from rock-fluid interaction associated with intrusions, resulting in ore formation by replacement of carbonate rocks. This type of deposit is found on continental margins of orogenic belts and on the inner side of principal arcs where carbonate rocks representing miogeoclinal or stable platform depositional environments are widespread. The deposits are associated with magmatic intrusions that are believed to be a result of subduction.
LTM deposits also have great vertical extents along the margins of dikes and stocks. Major ore bodies extend over vertical distances of 1,000 meters with concordant skarn and massive sulfide bodies.
Yauricocha is an LTM deposit, based on its regional and local geologic setting, mineralization styles, and deposit types. The Central Mine Area of Yauricocha has been mined from the surface to 520 m depth, or to Level 820, by various previous owners. The total production from this zone is 19,971,551 tonnes and the table below shows the production by company for only the Central Mine Area.
|Company||Production Years||Total Tonnes Produced|
|Cerro de Pasco Corporation||1961-1971||3,485,587|
The current mine workings are developed down to Level 870 and drilled in some areas to Level 1220. Given that LTM deposits have vertical extensions of over 1,000 m, it is geologically reasonable to project the mineralized zones to Level 1420.
Method of Analysis
Samples are prepared at the Yauricocha lab facility in the Chumpe mill, which is on site. Core and channel samples from the mine are assayed utilizing one of two procedures. Silver, lead, zinc, and copper are assayed by atomic absorption. Gold is fire-assayed with an atomic absorption finish. Diamond drill samples sent for analysis consist of half NQ-size and BQ-size diamond core split on site.
The quality assurance-quality control (QA-QC) program employed by Dia Bras has been described in detail in the NI 43-101 Technical Report on Yauricocha, dated May 25, 2011, prepared by Gustavson Associates LLC of Lakewood, which is available for review on SEDAR.
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 and Head of Exploration for Dia Bras Exploration, Inc.
About Dia Bras
Dia Bras Exploration is a Canadian mining company focused on precious and base metals in Chihuahua State, other areas of northern Mexico, and 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 Bolsa de Valores de Lima and 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.
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.
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