Dia Bras increases measured and indicated resources over 12-fold to 15.4 million tonnes at its Bolivar Property, Chihuahua State, Mexico
TSX Venture Exchange – DIB
Bolsa de Valores de Lima – DIB
TORONTO, Aug. 30, 2012 /PRNewswire/ – Dia Bras Exploration Inc. (TSX-V:DIB) (BVL: DIB) (“Dia Bras” or the “Company”) is pleased to announce a new resource
estimate on its Bolivar Property, Chihuahua State, Mexico. These
resources are in four areas of the Bolivar operating mine: 1) Alta Ley;
2) Increible; 3) Ell Gallo Superior; and, 4) El Gallo Inferior. This
resource estimate was prepared by Gustavson Associates, LLC
(“Gustavson”) of Lakewood, Colorado.
Press Release Highlights:
-- The total estimated Measured and Indicated Resources for the Bolivar Property are: o 15,404,000 tonnes averaging 19.4 g/t Ag, 0.79% Cu and 1.01% Zn at a mill feed cut-off grade of 0.66% CuEq. -- Total estimated Inferred Resources are: o 6,164,000 tonnes averaging 18.1 g/t Ag, 0.73% Cu and 0.93% Zn at the same cut-off. -- For the first seven months of 2012, the average mill feed grade to the Piedras Verdes mill is 2.02% CuEq. -- Drilling continues with the objective of expanding the resources of the property, especially in the area between El Gallo and Increible. -- The possibility of recovering magnetite from the Lower Skarn is being evaluated.
Daniel Tellechea, President and CEO of Dia Bras, commented: “These results demonstrate that the many years of exploration and pilot
mining done by the Company have paid off and our investment in the new
Piedras Verdes mill is very well supported. We have sufficient tonnes
to expand the mill to 2,000 tonnes per day capacity. The Company also
plans to initiate a Preliminary Economic Analysis with the objective of
moving some resources to reserves.”
Methods of Estimation
The major structures and mineralized zones were evaluated by Gustavson
using two different estimation methods.
1) The skarn mineralization within the El Gallo zone was modeled as a
stratigraphic unit with pockets of mineralization. The two zones
modeled were the upper and lower skarns. These units appear to be long,
continuous tabular bodies that grade from proximal to distal with
mineralization changing from copper dominant to zinc dominant. Both of
these zones were estimated using an ordinary kriging algorithm. All
drill holes that intersected the modeled horizons were coded for
estimation. If a sample was not assayed it was replaced with a value
equal to half of the detection limit for the analysis. This prevented
the spreading of economic minerals into areas without assays. It was
the assumption of Gustavson that areas that have not been assayed are
not mineralized and warrant the use of a below detection limit value.
2) The mineralization within the Alta Ley and Incre ble zones is very
complex. To overcome the complexities of the mineralization and
represent the multiple directions of mineralization Gustavson chose to
use a Multiple Indicator Kriging (MIK) algorithm. This algorithm allows
for the estimation of multiple grade cutoffs as probabilities of an
entire block. The probabilities of a block exceeding a particular
cutoff are then used to recreate the weighted average block grade.
Again Gustavson replaced missing sample intervals with a value equal to
half of the detection limit for the analysis.
Bolivar Property Resource Estimate
The following tables show the Bolivar Property Measured, Indicated, and
Inferred Resources at various cut-off grades. The 0.66% copper
equivalent cut-off grade was selected by Gustavson as a base case.
_____________________________________________________________________ | Total Bolivar Measured Resources | |_____________________________________________________________________| | | | Copper | | | | |Cutoff| Tonne | Equivalent | Silver | Copper | Zinc | |______|________|_____________|___________|_____________|_____________| | | | |lbs. (x| |oz. (x| |lbs. (x| |lbs. (x| |%CuEq |(x 1000)| % | 1000) |gpt |1000) | % | 1000) | % | 1000) | |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.85% | 6,394 |1.59%|223,658|26.4|5,431 |1.00%|140,780|1.20%|169,658| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.75% | 7,584 |1.46%|244,605|24.2|5,891 |0.93%|155,501|1.08%|181,048| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.66% | 8,847 |1.35%|264,205|22.3|6,333 |0.87%|169,423|0.98%|190,851| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.55% | 10,800 |1.22%|290,252|19.9|6,917 |0.79%|188,163|0.85%|203,091| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.45% | 12,927 |1.10%|313,629|17.8|7,410 |0.72%|204,787|0.76%|215,594| |______|________|_____|_______|____|______|_____|_______|_____|_______| | Total Bolivar Indicated Resources | |_____________________________________________________________________| | | | Copper | | | | |Cutoff| Tonne | Equivalent | Silver | Copper | Zinc | |______|________|_____________|___________|_____________|_____________| | | | |lbs. (x| |oz. (x| |lbs. (x| |lbs. (x| |%CuEq |(x 1000)| % | 1000) |gpt |1000) | % | 1000) | % | 1000) | |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.85% | 3,898 |1.41%|121,079|19.2|2,401 |0.81%|69,412 |1.26%|108,330| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.75% | 5,075 |1.27%|141,788|17.2|2,806 |0.74%|82,669 |1.15%|128,432| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.66% | 6,557 |1.14%|164,706|15.6|3,285 |0.67%|97,316 |1.05%|151,389| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.55% | 9,190 |0.99%|199,624|13.5|4,003 |0.59%|120,449|0.89%|179,440| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.45% | 12,611 |0.85%|237,264|11.9|4,824 |0.52%|145,938|0.75%|207,845| |______|________|_____|_______|____|______|_____|_______|_____|_______| | Total Bolivar Measured & Indicated Resources | |_____________________________________________________________________| | | | Copper | | | | |Cutoff| Tonne | Equivalent | Silver | Copper | Zinc | |______|________|_____________|___________|_____________|_____________| | | | |lbs. (x| |oz. (x| |lbs. (x| |lbs. (x| |%CuEq |(x 1000)| % | 1000) |gpt |1000) | % | 1000) | % | 1000) | |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.85% | 10,292 |1.52%|344,738|23.7|7,832 |0.93%|210,192|1.23%|277,987| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.75% | 12,659 |1.38%|386,393|21.4|8,697 |0.85%|238,170|1.11%|309,480| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.66% | 15,404 |1.26%|428,912|19.4|9,619 |0.79%|266,739|1.01%|342,240| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.55% | 19,990 |1.11%|489,876|17.0|10,920|0.70%|308,613|0.87%|382,530| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.45% | 25,538 |0.98%|550,893|14.9|12,234|0.62%|350,725|0.75%|423,440| |______|________|_____|_______|____|______|_____|_______|_____|_______| | Total Bolivar Inferred Resources | |_____________________________________________________________________| | | | Copper | | | | |Cutoff| Tonne | Equivalent | Silver | Copper | Zinc | |______|________|_____________|___________|_____________|_____________| | | | |lbs. (x| |oz. (x| |lbs. (x| |lbs. (x| |%CuEq |(x 1000)| % | 1000) |gpt |1000) | % | 1000) | % | 1000) | |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.85% | 3,824 |1.42%|119,675|22.2|2,729 |0.88%|74,558 |1.17%|69,448 | |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.75% | 5,035 |1.27%|140,846|19.9|3,222 |0.79%|87,390 |1.05%|75,437 | |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.66% | 6,164 |1.17%|158,434|18.1|3,590 |0.73%|99,796 |0.93%|106,444| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.55% | 7,772 |1.05%|179,615|16.1|4,033 |0.67%|114,431|0.81%|129,273| |______|________|_____|_______|____|______|_____|_______|_____|_______| |0.45% | 9,120 |0.97%|194,470|15.1|4,413 |0.62%|124,009|0.74%|144,754| |______|________|_____|_______|____|______|_____|_______|_____|_______|
* Ag gpt * Ag Price * Ag CuEq(%) = Cu % + Zn % * Zn price * Zn + recovery recovery 22.0462 * Cu price * Cu price * Cu recovery 31.10348 * Cu recovery
Quality and grade are estimates and are rounded to reflect the fact that
the resource estimate is an approximation.
Mineral Resources are not Mineral Reserves and do not demonstrate
economic viability. There is no certainty that all or any part of the
Mineral Resource will be converted to Mineral Reserves.
The property is currently in full commercial production. Mining started
at Bolivar as a pilot project to evaluate the deposit’s technical and
economic viability. This has gradually expanded to the current
commercial production status of over 1,000 tpd, which represents a
three-fold increase over our 2011 capacity. No feasibility study has
been completed, however, which may lead to increased technical and
The Company is continuing an aggressive drilling program between the El
Gallo and Increible deposits with the objective of expanding the
resources of both deposits as well as discovering high-grade copper
deposits at the intersection of the Upper and Lower Skarn horizons with
the Increible breccia pipe.
During the period January through end-July, the Piedras Verdes mill
processed 170,609 tonnes averaging 19.0 g/t silver, 1.15% copper, and
2.54% zinc, which equates to a CuEq grade of 2.02%.
The Lower Skarn contains abundant magnetite, ranging from 10 to 30% by
volume with occasional lenses and pods of massive magnetite. The
Company is evaluating the feasibility of recovering the magnetite as a
by-product through metallurgical testing and consideration of the
additional recovery equipment required.
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
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. Zachery Black
of Gustavson Associates was responsible for the resource estimate. Mr.
Black is a Qualified Person as defined in NI 43-101 and an Associate
Senior Resource Geologist.
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
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.