Oct 14 2010
Alturas Minerals Corp. (TSX VENTURE:ALT)(BVLAC:ALT) announces assay results from the first five diamond drill holes completed as part of the first phase drill program at its La Corina property in northern Chile.
Highlights include a section in one drill hole of 47.8 meters grading 0.90 grams/tonne gold, which included sections of 3.05 meters grading 2.33 grams/tonne and 4.00 meters grading 2.87 grams/tonne gold.
Miguel Cardozo, Chairman and Interim President and CEO of Alturas commented, "The exploration program at La Corina has defined an east-west striking, gold-bearing vein/breccia system traceable on surface by strong alteration, siliceous veins/breccias, and gold-anomalous soils and rocks over a strike length of at least three kilometres. Three of the five widely-spaced drill holes reported lie within this auriferous structural corridor, with the best gold results reported in the most easterly holes (COR-03 and COR-04). Surface gold-in-rock values appear to strengthen to the east, and the most encouraging gold intercept reported in hole COR-03 remains open at depth and to the east.
The six-hole first phase drilling program has now been completed; assay results are currently awaited for the sixth and final hole. Alturas will evaluate the merits of further drill exploration eastwards along the auriferous corridor."
Assay results received to date are as follows:
Vein and breccia gold target
The east-west corridor of alteration, brecciation, rhyolite dykes and gold mineralization is the principal mineralized feature recognized on the property to date. This broader corridor averages a few hundred meters in width but within this envelope, steeply-dipping gold-bearing structures marked by abundant brecciation, and banded silica and pyrite, form discrete zones, meters to tens of meters in width. One of such sub-vertical zones was intersected beneath Cerro Pingo in drill hole COR-03, which reported best gold grade (47.8 meters grading 0.90 grams/tonne gold) correlating with strong brecciation of porphyry and quartz-sericite-pyrite alteration. Drill hole COR-04 drilled beneath outcropping gold-bearing breccias at Lavaderos some 530 meters to the west intersected 18.0 meters grading 0.22 grams/tonne gold in an interval of quartz-sericite–altered porphyry cut by banded quartz veinlets. The true widths of the gold-rich zones reported are estimated to be approximately 50% of the down-hole intercept lengths reported.
The present surface sampling and drill hole results appear to indicate that siliceous veins and breccias within the east-west gold corridor defined at La Corina generally increase in gold tenor to the east. In addition, the bifurcation of a rhyolite dyke system mapping the location of the mineralized corridor possibly indicates an "overstep" geometry associated with increased structural dilation to the east of Lavaderos/Cerro Pingo.
High level auriferous vein systems of this style tend to vary markedly in gold grade along strike and downdip; widely spaced drill holes generally are inadequate in fully testing their economic potential. Results obtained to date in drill holes COR-03 and COR-04 demonstrated that gold-bearing structures extend from surface down to a vertical depth of at least one hundred meters and are still open at depth. The Company is evaluating the possibility of further drill exploration of the gold zone in the Lavaderos- Cerro Pingo segment and further east.
Porphyry copper-gold target
Encouraging copper-gold results were previously reported in stockwork-veined intrusive rocks in historical drilling beneath the old La Corina Mine. Two of Alturas´s drill holes in the current program (COR-01 and COR-02) were directed at testing the porphyry potential of adjacent high chargeability zones previously defined by the Company, beneath the "Cerro Gris" geochemical anomaly. Porphyritic and equigranular intrusive rocks were intersected in these two drill holes, cut by widespread tourmaline- bearing breccias and distal porphyry-style alteration (propyllitic, argillic and sericitic). Copper and zinc values (> 0.1%) reported in the two drill holes, whilst moderately anomalous over intervals of several meters, are in themselves not of economic interest.
The conclusion reached by the Company is that significant porphyry-style copper-gold mineralization, if present within the property, must lie at depths in excess of those attained by drill holes COR-01 and COR-02 (i.e. > 200 meters).
About the La Corina Copper-Gold project
The 1,423 hectare La Corina project is located 70 kilometres northeast of the city of La Serena in Region IV of northern Chile. In the La Corina area, a Paleocene volcanic complex has been intruded by Eocene intrusive rocks; strong hydrothermal alteration and mineralization are associated with the intrusive phases.
The property has received limited historical drilling in campaigns by Phelps Dodge in 1985 (11 holes for 556 metres) and by the Chilean national agency ENAMI in 2006 (10 holes for 997 meters). During 2010, Alturas has recently completed a 1,400 meter first phase diamond drill program over the property, targeting copper-gold porphyries and higher grade, gold-copper breccia pipes and veins concealed beneath the extensive shallow cover. Details of Alturas´s first phase drill holes are tabled below:
About Alturas's QA/QC Procedures.
Strict sample integrity is maintained throughout the geochemical sampling program. The bagged samples are transported by Alturas staff to Australian Laboratory Services (ALS) in the city of La Serena in northern Chile, where samples are prepared and then sent to the ALS analytical facility in Santiago de Chile. All samples are prepared by first drying them, then they are crushed to 70% -10 mesh (<2mm) size; then riffle split to obtain an approximately 250 gram subsample. The subsample is further crushed to 85% -200 mesh (<75 microns) to obtain a 100 gram split ready for analysis. All samples are routinely assayed for gold by conventional fire-assay methods at the ALS facility, and for 35 additional elements (including silver, copper, lead, zinc) using aqua regia acid digestion followed by Inductively Coupled Plasma-Atomic Emission Spectroscopy ("ICP-AES") analysis.
Alturas follows a rigorous QC/QA program, including routine insertion of standards and blanks as well as assay of duplicate samples at other independent laboratories. Certified standards, of known gold grade are inserted "blind" every 20th sample as an independent check on assay accuracy.
As required by the National Instrument 43-101, Alturas's designated Qualified Person for the supervision of exploration of the projects is Dr. Paul Pearson, F. AUSIMM, who has reviewed the technical information reported in this News Release.
Source: Alturas Minerals Corp.