Dia Bras Drilling Expands Catas-Cuye Deposits and Discovers High-grade Gold at the Purisima Area on its Yauricocha Property, Peru

TSX Venture Exchange - DIB
Bolsa de Valores de Lima - DIB
# 15-2012

TORONTO, May 3, 2012 /PRNewswire/ - Dia Bras Exploration Inc. (TSX-V:DIB) (BVL: DIB) ("Dia Bras" or the "Company") is pleased to announce that its drilling programme for resource expansion at the Yauricocha mine in Peru continues to find additional ore below the current levels.  An additional eight holes have been drilled and have expanded the deposit to the south and 350 m to depth.  Also, drilling in the Purisima area of the property yielded high grades of gold in several drill holes.

Press Release Highlights:

  • Yauricocha mineralization expanded further:
    • Drill hole CA-14-12-13 cut 18 m width in the Catas ore body averaging 98.1 g/t silver, 1.92 g/t gold and 4.88% copper, including 4.0 m averaging 218.1 g/t silver, 3.82 g/t gold and 12.36% copper.
      • This hole is 270 m below the deepest mine working.
    • Drill hole CA-14-12-20 expanded the limits of the previously-unknown ore body (herein named Adriana) and also cut the Catas body:
      • The Adriana polymetallic body was intercepted over 20.1 m width averaging 60.3 g/t silver, 1.65% lead and 10.04% zinc.
      • Catas body over 11 m width averaging 18 g/t silver and 6.1% zinc, plus 8.0 m averaging 95 g/t silver and 1.49% copper.  The hole is 320 m below the deepest mine working.
  • Drilling of the Purisima Anticline returned potentially-economic levels of gold, such as drill hole PC-12-08 that cut 3.0 meters averaging 20.65 g/t gold.

  • Exploration outside the immediate mine area will begin after the rainy season ends in June.  This is the first exploration program of this type conducted on the Yauricocha property.  Three areas will be explored first:
    • Adrico: Underground drilling of Yauricocha fault and down-dip extension of Adrico disseminated gold deposit 500 m SSE of main deposits.
    • Ipillo: Drilling of wide area of silver-lead-zinc stockwork mineralization. Yauricocha Fault: Mapping, sampling and Induced Polarization surveys along unexplored 6-km extension of fault SSE of main mine area. An updated 43-101 report will be published in mid-May.
    • Yauricocha Fault: Mapping, sampling and Induced Polarization surveys along unexplored 6-km extension of fault SSE of main mine area.

Daniel Tellechea, President and CEO of Dia Bras, commented: "These results demonstrate that we continue to expand the resources of the Yauricocha mine and continue to prove the prolific nature of this highly mineralized mining district.  We know now that the Catas and Cuye orebodies extend more than 350 m to depth, and our drilling continues to discover previously-unknown deposits that also are expected to extend for hundreds of meters down dip.  This mature, productive mine has many, many years of production before it and its precious metal potential is being reinforced with recent discoveries of high grade gold at its Purisima area, which is only 500 meters away from current mine working areas."

Recent Drilling Results

Yauricocha Mine: Drilling of the Catas and Cuye bodies below the mine workings continues to demonstrate that these wide, high-grade ore bodies continue to depth (see link to "Yauricocha Longitudinal Section" here).  The deposits are of high-temperature, carbonate-replacement type, which is an important distinction because these types of deposit often have great vertical extent.  The Company expects that these bodies will continue to great depth, much deeper than the depth to which current drilling has shown the deposits to occur.

Assay results from recent drill holes are shown in the table below:

Catas Extension

Hole #* To-From
(m)
Core
Length (m)
g/t Ag % Pb % Cu % Zn Au g/t Deposit
12-12 310.4-313.0 2.6 0.6 0.31 0.11 0.94 0.26 Polymetallic
12-13 61.3-63.0 1.7 8.7 0.48 0.02 3.03 0.07 Oxide
  76.8-78.0 1.2 7.9 0.11 0.01 15.63 0.01 Oxide
  111.8-113.0 1.2 209.1 5.0 0.48 11.00 0.75 Oxide
  206.8-210.6 3.8 5.7 0.01 0.01 14.59 0.00 Breccia
  266.9-276.2 9.3 18.5 0.21 0.10 5.26 0.19 Breccia
  297.0-315.0 18.0 98.1 0.03 4.88 0.11 1.92 Catas
Incl. 304.0-308.0 4.0 218.1 0.02 12.36 0.09 3.82 Catas
12-14 328.1-337.0 8.9 6.6 0.15 0.16 16.8 0.02 ?
12-15 56.4-85.2 28.8 25.7 0.82 0.13 19.63 0.03 Oriental
  180.3-187.1 6.8 1.0 0.02 0.0 4.98 0.05 Oriental
  204.3-211.1 6.8 101.3 1.15 0.27 3.55 1.97 Polymetallic
  241.0-254.0 13.0 33.95 0.19 0.20 2.78 3.13 Polymetallic
12-16 69.6-78.0 8.4 66.8 1.05 0.04 8.26 0.24 Oxide
  81.35-82.50 1.15 231.1 8.9 0.20 8.94 0.25 Oxide
12-17 95.2-98.3 3.1 111.1 5.55 0.07 3.91 0.25 Oxide
  252.5-258.4 5.9 25.7 0.08 0.96 0.27 0.62 Pyritic
12-18 79.6-87.0 7.4 108.6 3.11 0.28 17.28 0.26  
  221.0-222.7 1.7 105.9 0.25 0.09 2.35 0.33  
12-19 39.8-43.5 3.7 823.0 33.32 0.18 0.60 0 Oxide
  84.6-86.0 1.4 5.5 0.16 0.03 30.13 0.3 Oxide
  187.5-200.5 13.0 7.9 0.04 0.01 1.75 0.03 Polymetallic
  254.5-270.0 15.5 37.6 0.08 0.46 4.40 1.68 Polymetallic
12-20 62.7-72.1 9.4 124.4 5.80 0.22 2.55 1.68 Oxide
  115.3-116.8 1.5 284.9 1.14 0.85 23.95 2.46 Poly Bx
  224.0-244.1 20.1 60.3 1.65 0.26 10.04 0.29 Adriana
Incl. 231.0-234.7 3.7 75.7 1.16 0.28 14.33 0.43 "
Incl. 241.5-244.1 2.6 148.9 6.77 0.99 29.89 0.23 "
  290.0-291.1 1.1 377.2 0.59 4.43 1.0 0.08 Intr. Contact
  410.7-447.9 37.2 29.3 0.02 0.75 2.07 0.39 Polymetallic
Incl. 412.0-423.0 11.0 17.8 0.04 0.47 6.10 0.37 "
Incl. 428.0-436.0 8.0 95.0 0.02 1.49 0.60 0.27 "

* All holes have the prefix CA-14-

Purisima Area: This area is located about 500 meters SW of the active mining area at the Catas and Cuye ore bodies.  Twelve reconnaissance drill holes have been completed at wide spacings to test gold mineralization along the overturned Purisima Anticline (see link to "Tal-12-11 Cross Section" here).  Ten of the holes returned potentially-economic levels of gold.  Gold mineralization is associated with brecciated calcareous rocks, often bituminous. Although the gold mineralization is associated with a specific host rock, drilling is too wide-spaced to determine if it is stratigraphically or structurally controlled.  The presence of gold mineralization in the same stratigraphic layer on both sides of the overturned anticline, however, indicates that the mineralization is probably stratigraphically controlled.

Additional holes are required to determine the true width, extent and orientation of the mineralization, which are planned to be drilled later in the year after further interpretation of these results has been completed.

The table below shows the results from holes 3 through 12:

Hole # To-From
(m)
Core
Length (m)
Ag g/t % Pb % Cu % Zn Au g/t
PC-12-03 130.0-133.0 3.0 12.0 0.01 0.00 0.02 5.87
PC-12-04 136.5-152.0 15.5 2.4 0.02 0.00 0.01 1.08
Incl. 148.0-152.0 4.0 7.4 0.06 0.01 0.03 3.98
PC-12-05 54.8-56.8 2.0 62.6 0.03 0.00 0.06 1.64
PC-12-06 62.8-69.2 6.4 22.9 0.02 0.00 0.02 1.20
and 162.7-164.0 1.3 48.0 0.23 0.01 0.05 3.33
PC-12-07 54.0-55.0 1.0 14.4 0.02 0.00 0.01 1.96
and 233.0-235.0 2.0 7.0 0.00 0.00 0.03 1.19
PC-12-08 61.0-64.0 3.0 9.4 0.01 0.00 0.02 20.65
PC-12-09 51.0-60.0 9.0 51.1 0.02 0.00 0.02 1.33
Incl. 51.0-55.0 4.0 104.3 0.03 0.00 0.00 1.21
Incl. 55.0-60.0 5.0 8.5 0.02 0.00 0.01 1.43
PC-12-10 62.0-64.7 2.7 1.56 0.01 0.00 0.01 1.82
and 67.0-72.7 5.7 21.1 0.02 0.01 0.02 9.58
PC-12-11 68.4-73.1 4.7 6.4 0.02 0.00 0.03 1.39
and 83.5-86.7 3.2 5.9 0.02 0.00 0.04 3.14
and 92.0-94.0 2.0 12.7 0.02 0.00 0.04 2.59
and 138.0-140.0 2.0 60.3 0.07 0.01 0.38 1.44
PC-12-12 87.3-89.0 1.7 25.3 0.06 0.00 0.02 2.23
and 95.4-97.5 2.1 38.7 0.12 0.00 0.02 3.71

Significance of Drill Results

Drilling in the Yauricocha mine over the past few months has demonstrated that both the Catas and Cuye bodies continue to depth with good widths and grades of mineralization.  Mineralization in both bodies is open along strike and down dip, and the carbonate/intrusion contact along the Yauricocha fault for several hundred meters to the SSE remains to be tested.

The potential to define significantly more economic mineralization in the Yauricocha area has been greatly expanded by these results.  The discovery of a previously-unknown deposit (Adriana) in the immediate vicinity of the mine workings demonstrates the strength of the mineralizing system and bodes well for the definition of more mineable bodies.  The Company intends to continue drilling these areas in order to increase significantly the mineable resources of the property.

Intercepts of gold mineralization at Purisima demonstrate that potentially-economic grades and widths of gold occur in the area.  Additional drilling is required to determine the extent and continuity of these widely-separated intercepts, but results from this program are very encouraging.

Exploration Program of mid 2012

During 2012, Dia Bras will also explore other targets identified by its mine geology staff, most of which will begin in June, after the rainy season has ended.  These are:

  • Adrico: An underground drill station is being developed at the end of the 400-m-long Victoria adit, on Level 330.  Drilling is scheduled to commence in early June.  The primary target is the contact of the Yauricocha intrusion with the main limestone host rock of the main deposits of the Yauricocha mine, which are located 500 m to the NNW.  An initial eight holes totalling 1,600 m are planned, with an additional six holes planned to test the down-dip projection of the Adrico disseminated gold deposit.
  • Ipillo: This area has potential for open-pitable silver-lead-zinc stockwork of major tonnage.  Three drill holes are planned for the third quarter.
  • Yauricocha Fault: The south-eastern portion of this major ore-controlling fault extends six km from the Yauricocha mine to the eastern limit of the Yauricocha property.  This area has never been explored, but the fault cuts through calcareous lutites, pure limestones and arenaceous limestone, all of which are good host rocks.  The program is directed at identifying drill targets and will consist of geologic mapping, rock sampling and an Induced Polarization (IP) geophysical survey.  Work will begin in June.

Yauricocha Property Overview

The Company is currently the title holder of five (5) mining concessions with a combined area of 19,957.7174 hectares. The Yauricocha mine is located in the Alis district, Yauyos province, department of Lima approximately 12 km west of the Continental Divide and 60 km south of the Pachacayo railway station. The active mining area is in the high zone of the Andean cordillera at an average altitude of 4,600 masl.

The rich silver ores of Yauricocha were initially documented by Alexander von Humboldt in the early 1800s. In 1905, the Valladares family filed the claims of what is today the Yauricocha property. The Valladares family mined high-grade silver ore for 22 years and in 1927, Cerro de Pasco Corporation acquired the Yauricocha claims. In 1948, Cerro de Pasco commenced mining operations at Yauricocha until the Peruvian Military Government nationalized Cerro de Pasco Corporation and Yauricocha became a production unit of State-owned Centromin Peru S.A. for 30 years. In 2002, the Yauricocha unit was privatized and purchased by Sociedad Minera Corona S.A.  Dia Bras acquired 82% of the total equity of Corona in May, 2011.

Prior to the 1970s, detailed production records are unavailable. Since 1973, this mine has produced over 12.8 million tonnes of ore containing 59 million ounces of silver, 350 thousand tonnes of lead, 100 thousand tonnes of copper and 600 thousand tonnes of zinc.  During 2010, the mine produced 837,000 tonnes of ore averaging 163 g/t Ag, 3.4% Pb, 0.9% Cu and 3.2% Zn.

The carbonate-replacement ore deposits of the Yauricocha district are spatially and genetically related to the Yauricocha stock, a composite intrusive body of granodioritic to quartz monzonitic composition. The stock intrudes tightly folded beds of the Late Cretaceous Jumasha (limestone) and Celendín (lutite-limestone) Formations and the overlying Casapalca (lutite-limestone) Formation (latest Cretaceous and Paleocene?).

The principal orebodies of the Yauricocha district, located near the western margin of the Yauricocha stock, are related spatially and genetically to the main body of the stock and to narrow fingers of granodiorite that presumably connect at depth to a western extension of the stock. The orebodies consist of vertically elongate pipes composed largely of pyrite and other sulfide minerals that replace limestone of the Jumasha Formation. Skarn is developed adjacent to the stock but does not host appreciable amounts of ore. The pipes typically exhibit both vertical and radial zoning and there is a pronounced district zoning, with an inner core of enargite (the principal copper mineral) giving way outward to an enargite-chalcopyrite-bornite zone, which in turn is succeeded to the west by zones characterized by sphalerite, galena, lead and silver. Mineralization of the Yauricocha deposit is formed principally by pyrite, quartz, enargite, chalcopyrite, bornite and covellite in the core and central parts of the bodies. Loose masses of friable pyrite, galena, sphalerite and minor amounts of chalcopyrite in a gangue of limestone, clay and quartz occur in the periphery of the bodies. Also, native gold is associated with these sulfide minerals.

Update of NI 43-101 Report

The Company has commissioned an update of the NI 43-101 compliant resource calculation, dated May 25, 2011, for the Yauricocha property and the required property visit was made by a representative of Gustavson Associates, Lakewood, Colorado, during mid-April.  The final report is expected during mid-May.

Option Granting

The Company also announces that it has granted 42,857 options to a director who is also an officer. The options are exercisable at $3.40 over a five-year period and vesting over two years.

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.

Quality Assurance

The quality assurance-quality control (QA-QC) program employed by Dia Bras has been described in detail in the NI 43-101 report on Yauricocha of May 25, 2011, prepared by Gustavson Associates of Denver, 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 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, 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.

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.

PDF available at: http://stream1.newswire.ca/media/2012/05/03/20120503_C3459_DOC_EN_13037.pdf

PDF available at: http://stream1.newswire.ca/media/2012/05/03/20120503_C3459_DOC_EN_13038.pdf




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