TORONTO, ONTARIO--(Marketwire - June 28, 2011) - Dia Bras Exploration Inc. (News - Market indicators) ("Dia Bras" or the "Company") is pleased to report that drilling at the Corralitos project on its 100% owned Batopilas Property, located in Chihuahua State, Mexico, has yielded extensive grades of molybdenum. Seventeen holes totaling 4,640.1 m have been drilled to test a 2,000 x 3,000 m area of alteration, and partial assays have been received for five holes. Molybdenite has been observed in all holes to their final depth. This Phase 1 drilling program will be followed by a second phase to test the mineralized zone at depth and will commence after all assay results have been received and interpreted, and after the rainy season, that should end in late October. The Phase 2 program will be designed to result in a 43-101 compliant resource calculation for the target area.
"These results are very promising," stated Daniel Tellechea, President & CEO, "because our drilling confirms that our surface sampling results identified the presence of extensive molybdenum and copper mineralization. Molybdenum mineralization occurs over extensive core lengths. Because mineralization extends from the surface to the limit of the drill holes, we believe this project could contain a molybdenum deposit that could become a significant asset for the Company."
During late 2010, the Company conducted a geologic mapping and rock chip sampling program of the Corralitos area, which revealed highly anomalous molybdenum and copper values associated with extensive alteration. The geologic map of the Corralitos prospect area http://www.diabras.com/files/media/f3c95_NR%2025%20Corralitos%20Drill%20Hole%20Location%20Map%20w%20Geology.png shows that the molybdenum-copper mineralized area covers an area of approximately 2,000 x 3,000 m. The mineralized zone remains open in all directions.
The Phase 1 drilling program was designed to test the surface Mo-Cu anomalies as well as the possibility of silver mineralization in steeply-dipping quartz veins of the type that occur in the region. Because of this, the drill holes in this program are inclined holes, which reveal extensive disseminated and quartz-veinlet-hosted molybdenum and copper mineralization but also show that silver-bearing quartz veins of that type do not occur in the drilled area. As a result, the drill holes in Phase 2 will be vertical holes designed to identify a bulk-tonnage, open-pitable mineralized body.
Assay results are shown in Table 1 http://www.diabras.com/files/media/98058_NR%20No%2025%20Table%201.pdf, and individual results for all samples of the five drill holes, DCO11B001 http://www.diabras.com/files/media/56d5e_DCO11B001.pdf, DCO11B002 http://www.diabras.com/files/media/0a294_DCO11B002.pdf, DCO11B003 http://www.diabras.com/files/media/c2669_DCO11B003.pdf, DCO11B004 http://www.diabras.com/files/media/fb2dc_DCO11B004.pdf and DCO11B005 http://www.diabras.com/files/media/41764_DCO11B005.pdf are available on the Company's website. Individual values range up to 1.14% molybdenum. Because molybdenum-copper mineralization occurs throughout every drill hole, which requires sampling the entire 4,640 m of drill core, and the lengthy assay turn-around times, the core has been sampled in intervals in order to obtain an over-view of the mineralization in the holes. Sampling of core continues, but due to these factors, all assay results may not be received until late August. In addition, the Company is having the initial samples re-assayed by a method that will ensure total dissolution of molybdenite and provide more accurate results, as described below. It is important to emphasize that these are only partial results and more core remains to be assayed from the five holes reported here.
Table 1: Partial Drill Core Assay Results for Corralitos Prospect
Drill
Hole #* |
From (m) |
To (m) |
Core Length (m) |
Cu % |
Mo % |
Ag g/t |
Au g/t |
| 001 |
0.00 |
129.00 |
129.00 |
0.029 |
0.027 |
2.55 |
0.02 |
| incl. |
14.20 |
32.20 |
18.00 |
0.069 |
0.068 |
6.57 |
0.02 |
| incl. |
11.65 |
70.40 |
58.75 |
0.043 |
0.042 |
2.73 |
0.01 |
| 002 |
0.00 |
126.40 |
126.40 |
0.036 |
0.030 |
2.26 |
0.01 |
| incl. |
14.70 |
49.15 |
34.45 |
0.110 |
0.060 |
3.88 |
0.02 |
| 003 |
no significant values |
| 004 |
2.50 |
265.20 |
262.70 |
0.062 |
0.022 |
2.13 |
0.02 |
| incl. |
2.50 |
163.30 |
160.80 |
0.080 |
0.022 |
2.11 |
0.02 |
| incl. |
5.55 |
47.05 |
41.50 |
0.141 |
0.051 |
2.14 |
0.01 |
| 005 |
112.15 |
122.15 |
10.00 |
0.078 |
0.035 |
4.07 |
0.02 |
| and |
136.70 |
183.70 |
47.00 |
0.037 |
0.042 |
0.53 |
0.01 |
* Note: all holes have prefix DCO11B
The Corralitos area is underlain by hydrothermally-altered, coarse-grained granodioritic to monzonitic intrusions and adjacent volcanic and volcaniclastic rocks of probable Cretaceous age. Molybdenum and copper mineralization occurs in these intrusions in veinlets and as disseminations with coarse molybdenite and chalcopyrite http://www.diabras.com/files/media/d513e_NR25%20Corralitos%20Drill%20Core.png. Host rocks are intruded by andesitic dykes, both pre- and post-mineralization. A large phyllic alteration zone covering about 900,000 m2 is accompanied by much broader argillic and propylitic alteration. Oxidation creates a conspicuous color anomaly http://www.diabras.com/files/media/e3043_NR%2025%20Corralitos%20Alteration%20resized%20960x700%20for%20website.png. The oxidation zone is continuous to about 20 m depth.
Mineralization consists of megascopic and microscopic molybdenite, pyrite, minor chalcopyrite and rare bornite.
The Corralitos mineralization is only two km from the village of Batopilas, with access to a regional highway, labor, power grid, etc. This existing infrastructure will have a significant positive effect on future operation costs.
Method of Analysis
Samples were prepared at the ALS Chemex lab facility in Chihuahua, Mexico, and analyzed at their facilities in Vancouver, Canada. The samples were originally analyzed by ME-ICP41 method, which uses aqua regia digestion but with this method some base metals may dissolve only partially. Data reported from an aqua regia leach should be considered as representing only the leachable portion of the particular sample.
In order to ensure more complete dissolution of the abundant molybdenite in the samples and a more accurate determination of molybdenum, Dia Bras has ordered all drill core samples from Corralitos to be analyzed by ME-ICP61 method, which utilizes a four-acid digestion process and results in a more complete dissolution of molybdenite, although complete dissolution is not guaranteed.
Selected samples will also be analyzed by ME-MS61 method in order to determine contents of elements such as rhenium, rubidium and lithium, with the objective of providing additional geochemical data that will allow the Company's geologists to determine the type of Mo-Cu deposit at Corralitos.
Quality Control
The quality assurance-quality control (QA-QC) program employed by 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 Director of Dia Bras, and a Qualified Person as defined in NI 43-101.
About Dia Bras
Dia Bras Exploration Inc. is a Canadian listed mining company focused on precious and base metals in Peru and Mexico. The Company owns and operates the Yauricocha Mine (Ag-Cu-Zn-Pb) in Central Peru and the Bolivar Property (Cu-Zn-Ag) in Chihuahua State, Mexico. Dia Bras is also pursuing the development and exploration of the Cusi Property (Ag) and exploring several precious metals targets such as La Cascada (Bolivar Property), Las Coloradas (Melchor Ocampo, Zacatecas State), Bacerac (Sonora State) and Corralitos, Satevo and La Verde projects at the Batopilas Property (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. 
