- Published: 20 October 2008
- Written by Editor
Linear Metals' Cobre Grande Project Expands With Western Skarn and Discovery of Porphyry Molybdenum Deposit
Linear Metals Corporation (TSX:LRM) is pleased to report that the final two drill-holes of the 2008 diamond drill program at its Cobre Grande Project, located in Oaxaca, Mexico, have returned intercepts confirming significant copper skarn mineralization on the west side of the porphyry in the El Oso Zone. Equally important, both drill-holes have long porphyry hosted molybdenum intercepts beneath and adjacent to the copper skarn intervals.
These most recent results, from the Cobre Grande project, provide strong evidence that a north-south elongate porphyry system, estimated to have a minimum length of 1.4 kilometres, is host to classic stockwork molybdenum mineralization.
Furthermore, the results from these drill-holes show that the mineralized porphyry lies interior to a surrounding skarn body which in section would look like an upside down "V". Previous drill results, from the El Oso and Main Zones, have confirmed that the skarn making up the eastern leg of the "V" has a minimum strike length of 1.6 kilometres. Assuming the skarn making up the western leg of the "V" has a similar strike length, and should the porphyry be mineralized along its full strike extent, the tonnage potential of the project expands significantly.
Both drill-holes, CG-70B and CG-71B tested the west side of the porphyry in the El Oso Zone, located approximately 500 metres west of Cobre Grande's Main Zone Resource (43-101 compliant resource hosting 49.8 million tonnes of 0.92% copper-equivalent) and after passing through copper skarn, both holes intersected molybdenum stockwork mineralization, within porphyry. Highlights include:
- CG-70B:
-- 51.0 metres of 0.77% copper and 14 grams per tonne silver (0.94% copper equivalent);
-- 72.55 metres of 0.61% copper, 0.019% molybdenum, and 14 grams per tonne silver (0.82% copper equivalent); and bottomed in
-- 127.69 metres of 0.08% copper, 0.063% molybdenum, and 2 grams per tonne silver (0.74% copper equivalent); and
- CG-71B:
-- 15.3 metres of 1.07% copper, 0.046% molybdenum, and 21 grams per tonne silver (1.51% copper equivalent); and
-- 110.2 metres of 0.02% copper and 0.059% molybdenum (0.64% copper equivalent)
Vice President of Exploration, Dr. Robert Page reports that "eleven out of thirteen holes drilled in the El Oso Zone have contained significant copper, copper-molybdenum, or molybdenum intercepts." Dr. Page adds, "Most importantly, the El Oso Zone drilling, and in particular the final two holes of the 2008 drill program, CG-70B and 71B, show that Cobre Grande appears to host a porphyry molybdenum deposit with copper skarns on both the eastern and western flanks. The known resource within the Main Zone and the recent discovery on the eastern side of El Oso, are completely within the eastern flanking skarn. Now, drill-holes CG-70B and 71B have demonstrated that the west flanking skarn is also mineralized and clearly linked to the underlying porphyry molybdenum mineralization. The scale of El Oso's west flanking zone is impressive, extending effectively from surface to at least 400 metres depth. Furthermore, the 2008 exploration program, within the El Oso Zone, has confirmed that the entire down faulted top to the Main Zone copper skarn, the entire west flanking copper skarn, and a complete molybdenum porphyry system remain to be explored at Cobre Grande. All of these results support the potential for significant expansion of the resource base at Cobre Grande."
Results from the two new drill-holes in the El Oso Zone are included in the table below. A drill-hole location map is available on the Company's website at www.linearmetals.com.
Drill-holes in El Oso Zone
--------------------------------------------------------------------------
Copper
Molyb- Silver Equiv-
From To Interval Copper Zinc denum Grams/ alent
HOLE-ID (metres) (metres) (metres) % % % Tonne %
--------------------------------------------------------------------------
CG-70B 109.0 160.0 51.0 0.77 0.43 0.001 22 0.94(2)
--------------------------------------------------------------------------
237.45 310.0 72.55 0.61 0.26 0.019 14 0.83(3)
--------------------------------------------------------------------------
310.0 437.69(5) 127.69 0.08 0.01 0.063 2 0.74(4)
--------------------------------------------------------------------------
including 390.0 437.69(5) 47.69 0.04 0.01 0.091 2 1.00(4)
--------------------------------------------------------------------------
--------------------------------------------------------------------------
CG-71B 70.9 86.2 15.3 1.07 0.03 0.046 21 1.51(3)
--------------------------------------------------------------------------
86.2 90.8 4.6 0.59 0.03 0.014 11 0.59(1)
--------------------------------------------------------------------------
less
than
90.8 201.0 110.2 0.02 0.01 0.059 1 0.64(4)
--------------------------------------------------------------------------
less
than
including 105.0 175.0 70.0 0.01 0.02 0.069 1 0.74(4)
--------------------------------------------------------------------------
Notes: Drill-holes CG-70 and CG-70A were both lost at shallow depth in an
attempt to twin drill-hole CGRC-17 before the program successfully
completed drill-hole CG-70B as a twin to CGRC-17. Similarly, CG-71 and
CG-71A failed within 60 metres of surface before CG-71B was successfully
completed as a twin of CGRC-12. Intervals in the table are based on core
lengths and do not represent true widths of the zone. Copper equivalent
calculations are based on estimated NSR's with copper at $2.50 per pound,
molybdenum at $20.00 per pound, and silver at $13.50 per ounce. The copper
equivalent calculations also take into account assumptions regarding
concentrate properties, smelter charges, and payable percentages as well
as metallurgical recoveries (zinc is not expected to be recovered in any
of the mineralization types encountered in the holes reported here) which
vary between sub-zones, resulting in different copper equivalent formulas
for each zone as follows:
1. Oxide zone copper equivalent equals Cu% (until further testing is
carried out there is no expectation of recovering copper or any other
metals from the oxide zone).
2. Supergene-enriched, partially-oxidized copper-molybdenum zones copper
equivalent equals Cu%+Mo%($150.98/$37.84) + Ag g/t($0.27/$37.84).
3. Copper sulphide skarn copper equivalent equals Cu%+Mo%($233.01/$39.25)
+ Ag g/t($0.31/$39.25).
4. Molybdenum sulfide zone copper equivalent equals Cu%+Mo%(330.22/31.4).
5. Bottomed in mineralization.
El Oso Zone Skarn and Molybdenum Porphyry
As reported previously, the El Oso Zone is part of a large fault block which has been down dropped to the west from the top of the Main Zone which hosts a NI 43-101 compliant inferred resource of 49.8 million tonnes at 0.92% copper equivalent. Porphyry and skarn mineralization outcrop in the El Oso Zone over a strike length of 300 metres and based on the geological model, mineralization is expected to continue to the south, in parallel with the Main Zone, under unaltered limestone for at least an additional 1,000 metres, albeit at deeper levels.
The porphyry body in the El Oso Zone is elongate NE-SW and, based on previously reported shallow reverse circulation drilling in the spring of 2008, was indicated to have copper skarn mantling the western flank as well as the previously discovered eastern flanking skarn (previously reported drill-hole CG-68 returned 228 metres of 0.91% copper equivalent). The eastern flanking skarn, to this porphyry, is the down faulted top of the Main Zone and its geometry, zoning and grade are very similar to the Main Zone as shown by the results of CG-68.
Drill-hole CG-70B is a twin of the -70 degrees west directed reverse circulation drill-hole CGRC-17 which was lost in high grade copper mineralization at 146.3 metres. The first 2 coring attempts to twin CGRC-17, CG-70 and CG-70A were lost at shallow depth owing to caves in limestone overlying the skarn. Drill-hole CG-70B cut skarn hosting local strong supergene copper mineralization with a 51 metre interval starting at 109 metres carrying 0.94% copper equivalent (compares to a 32.3 metre interval in CGRC-17 with 1.37% copper equivalent). This mineralized upper zone is structurally complex and separated from the main skarn by barren limestone. The relation of the upper skarn interval to the main skarn which began at 237.45 metres in CG-70B remains to be determined.
Drill-hole CG-70B was the first deep test of the skarn on the west side of the porphyry at Cobre Grande. The hole returned a 72.55 metre intercept of 0.61% copper (0.83% copper equivalent) confirming that the west flanking skarn to the porphyry is mineralized and that this mineralization is visually indistinguishable from copper skarn mineralization on the east side of the porphyry. These results continue to support Linear's Cobre Grande exploration model in which the west flank of the 1.4 kilometre long porphyry is host to a "mirror image" of the Main Zone.
Equally important, drill-hole CG-70B showed there is a significant porphyry molybdenum zone immediately beneath the copper zone at El Oso. The hole encountered a strong quartz-molybdenite stockwork zone of 127.69 metres with 0.063% molybdenum below the copper skarn and bottomed at 437.69 metres in 47.69 metres of porphyry hosted 0.091% molybdenum mineralization. As a steep western dipping hole, CG-70B appears to have cut the westerly dipping copper bearing skarn and the adjacent molybdenum stockwork at an oblique angle.
Results of CG-71B, drilled 100 metres to the north, as an east directed twin to drill-hole CGRC-12, indicate that un-oxidized copper skarn and molybdenum porphyry mineralization come to within 70 metres of surface. Drill-hole CG-71B was drilled across the western flanking skarn and porphyry producing what is thought to be closer to true width intercepts. In combination, the two holes indicate a mineralized zone, comprised of a copper skarn mantling a molybdenum porphyry, with a minimum width of 120 metres which appears to extend from near surface to over 400 metres depth.
The Quality Control program at Cobre Grande is supervised by Linear Metals' Senior Resource Geologist, Geoff Chinn, P.Geo., who is a Qualified Person as defined under National Instrument 43-101. Drill core is sawn in half on site and samples collected over one to three metre intervals based on geology. Prior to shipping sealed sample bags are stored in a locked facility on site at the project. Samples are shipped via air to the ALS Chemex sample preparation facility in Guadalajara, Mexico. The Guadalajara prep facility then sends pulps to the ALS Chemex Vancouver, B.C. laboratory - ISO 9001-2000 registered. All samples are assayed for silver, copper, zinc, lead, and molybdenum using four acid digestion and ICP-AES analysis. In addition, samples from oxide zones are further analyzed for copper and zinc solubility. For copper, there is sequential analysis first with sulfuric acid leach and sequentially for cyanide leach. For zinc there is a single solubility analysis using acetic acid. The project uses a protocol that includes blanks, standards, and duplicates which make up 12% of each sample shipment.
This press release was prepared under the supervision of Linear Metals' Vice President of Exploration, Dr. Robert Page, P. Geo., who is a Qualified Person as defined under National Instrument 43-101. Dr. Page has reviewed the scientific and technical information in this press release.
For further details on Linear Metals Corporation and its Cobre Grande Project, please visit the Company's website at www.linearmetals.com.
Robert Page, Vice-President Exploration
Forward-Looking Information:
This release includes certain statements that may be deemed "forward-looking statements". All statements in this release, other than statements of historical facts, that address future production, reserve potential, continuity of mineralization, exploration drilling, exploitation activities and events or developments that the Company expects are forward-looking statements. Although the Company believes that the expectations expressed in such forward-looking statements are based on reasonable assumptions, such statements are not guarantees of future performance and actual results or developments may differ materially from those in the forward-looking statements. The likelihood of future mining at Cobre Grande is subject to a large number of risks and will require achievement of a number of technical, economic and legal objectives, including obtaining necessary mining and construction permits, completion of pre-feasibility and final feasibility studies, preparation of all necessary engineering for pits and processing facilities as well as receipt of significant additional financing to fund these objectives, as well as funding mine construction. Such funding may not be available to the Company on acceptable terms or on any terms at all. There is no known ore at Cobre Grande and there is no assurance that the mineralization at Cobre Grande will ever be classified as ore. For more information on the Company and the risk factors inherent in its business, investors should review the Company's Annual Information Form at www.sedar.com.
SOURCE: Linear Metals Corporation
Linear Metals Corporation Investor Relations (416) 216-4708 or North America Toll Free: 1-866-376-7683 Website: www.linearmetals.com
