Bellhaven Copper & Gold Inc. (TSX VENTURE:BHV) has announced that its fourth drill hole (DDH-13) targeting the Middle Zone discovered substantial gold and copper mineralization starting at a depth of 1.5 m.
The 77-m intercept reported in DDH-13 connects to the 94-m long intercept containing 0.76 g/t Au and 0.39% Cu (1.4 g/t AuEq) described in DDH-12 on November 2nd. Together these two intercepts demonstrate that gold and copper mineralization occur over a minimum vertical distance of 380 m.
The Middle Zone is the second porphyry prospect at La Mina, located approximately 500 m to the north of the La Cantera prospect. Bellhaven holds an option to earn 100% of the La Mina project (see press releases dated May 17, September 9, and October 12, 2010).
Paul Zweng, Bellhaven's Interim CEO and Director, commented as follows:
"We were surprised to drill a mineralized intercept starting only a meter or so below our feet at the Middle Zone. The view had always been that gold and copper at the Middle Zone occur at depth—below the argillic alteration zone—in contrast to La Cantera where gold and copper are found at surface. This discovery changes that thinking, as well as potentially improves the robustness of the Middle Zone as stripping and operating costs would be substantially lower compared to deeper mineralized zones."
"The 380 m (minimum) of vertical continuity of mineralization at the Middle Zone is impressive. It matches what we have found at La Cantera located some 500 m to the south. We are starting to gain a better understanding of the geometry of the Middle Zone and look forward to reporting additional drill results from the Middle Zone and La Cantera in the months ahead."
Discussion of the Drill-Hole Results
Bellhaven initiated its maiden 2000-m drilling program at its La Mina project last summer (see press release dated July 27, 2010). Three holes collared at the La Cantera prospect were reported in the September 9th press release. The first three holes drilled at the second prospect, the Middle Zone, were highlighted in the October 12th and November 2nd press releases.
Drill-hole DDH-13 was designed to test the up-dip extension of the 94-m long intercept found in DDH-12 at depth. No sample was recovered in the first 1.52 m of the hole. Starting at a depth of 1.52 m, the hole cut 76.83 m of mineralized porphyry and breccias. The mineralized interval was truncated by a late (post-mineral) barren dike and fault. Below the fault, the drill hole cut a large porphyry pluton and a series of narrow dikes which contained gold below the 0.4 g/t cut-off level. Although weakly to unmineralized, these rocks were altered to K-silicate ("potassic") alteration assemblages. The hole terminated at a depth of 335.28 m.
The cross section for DDH-12 and -13 was successful in discovering the surface extension of the 94-m intercept cut at depth in DDH-12. The zone cut by these two drill holes has a vertical continuity of at least 380 m and remains open at depth. The zone appears to be bounded by two near-vertical faults. The true width of the zone remains unknown at this time. It appears that the zone attains an apparent width of 100 m just below the surface. At depth, the zone bifurcates into two zones, with one measuring approximately 60-m wide and the other measuring approximately 10-m wide.
ALS Colombia Ltda. prepared the drill-core samples, producing the sample pulps in Bogota. The South American Central Lab of ALS Chemex in Lima, Peru, performed all assays pertaining to the drill-core samples highlighted. Gold was analyzed by fire assay on a 50-gram sample with an atomic-absorption finish. Copper was analyzed using four-acid digestion, ICP-AES. The Company maintains a QA-QC program regarding the preparation, shipping, and checking of all samples, including the use of certified standard reference materials, blanks, as well as field- and pulp duplicates.
This news release has been prepared under the supervision of Mr. Thomas J. Drown, P.Geo., who serves as the qualified person as defined by National Instrument 43-101 responsible for ensuring that the geological information in this release is accurate.
About the La Mina porphyry Au-(Cu) prospect
La Mina (also known as Venecia) lies within the Middle Cauca belt of Miocene-age volcano-plutonic rocks in central Colombia known to host large porphyry gold deposits such as La Colosa (12.9 Moz Au contained in 468 Mt @ 0.86 g/t Au; AngloGold Ashanti), Titiribi (3.7 Moz Au contained in 230 Mt @ 0.5 g/t Au; Sunward Resources), Quebradona (AngloGold Ashanti – B2Gold), Quinchia (Batero Gold), and Yarumalito (Colombian Mines), as well as large epithermal gold districts such as Marmato (7.5 Moz Au contained in 245 Mt @ 0.95 g/t Au; Medoro Resources).
In mid 2006, AngloGold Ashanti and Bema Gold drilled six holes into the La Mina porphyry (now called the La Cantera prospect), with Holes 2 and 5 yielding 90+ m intercepts of greater than 1 g/t Au and significant copper at shallow depths.
The most important host rocks observed in drill core include the Combia Formation intermediate volcanic rocks as well as early, intra- and post-mineral diorite porphyry. Alteration is typical of gold porphyry deposits as exemplified by a potassic-calcic core encircled by sericitic, intermediate argillic, and propyllitic alteration zones. Specifically, most of the gold and copper discovered so far at La Cantera are spatially associated with quartz-magnetite-chalcopyrite ± bornite veinlets in potassic altered porphyry and breccias containing elevated quantities of hydrothermal magnetite. As a result, the gold-bearing rocks are highly magnetic (ca. 200x10-3 SI) which creates a sharp contrast with the barren and weakly magnetic intermediate argillically altered rocks as well as the non-magnetic sericitically altered rocks that surround the potassic core.
Two other important targets occur due north of the La Cantera target: Middle Zone and El Limon. These three areas form a 1.5 km long by 0.5 km wide magnetic anomaly containing elevated values of gold and copper in rock-chip and soil samples.
Source: Bellhaven Copper & Gold Inc.