Bellhaven Copper & Gold Inc. (TSX VENTURE:BHV) has announced that DDH-16, the most recent drill hole targeting the La Cantera prospect, delivered the most significant intercept to date at La Mina: 1.62 g/t Au and 0.44% Cu (2.4 g/t AuEq) over 98.2 m.
This high-grade intercept occurs within a wider gold-copper zone occurring only 10 m (vertical) below the surface and averaging 0.91 g/t Au and 0.31% Cu (1.5 g/t AuEq) over 205.3 m. Further down the hole, Bellhaven cut a second intercept containing 0.60 g/t Au and 0.34% Cu (1.2 g/t AuEq) over 68.0 m.
La Cantera is the principal porphyry gold-copper prospect at La Mina, Colombia. Five other prospects occur within one km of La Cantera and include the Middle Zone, El Limon, El Cafetal, La Virgen, Filo de Oro, and El Tanque. Most of the concession still remains unexplored. Bellhaven holds an option to earn 100% of the La Mina project (see press release dated May 17th, 2010).
Paul Zweng, Bellhaven's Interim CEO and Director, commented as follows:
"We are excited to have discovered what we believe is the high-grade core to the La Cantera porphyry deposit. The elevated grades in DDH-16 correlate with the presence of bornite, a copper mineral known from other porphyry districts throughout the world to be associated with gold. The high-grade core, averaging 1.6 g/t gold and 0.44% copper over nearly 100 meters, is contained within a broader zone that averages just below 1 g/t gold over a considerable distance of 200 meters. After reviewing the drill-hole intercept data, it is clear that the consistently high grades produced from La Cantera—whether from the core or the fringe—substantiate La Cantera as one of the richest porphyry gold-copper deposits in the Middle Cauca belt of Colombia."
Discussion of the Drill-Hole Results
Bellhaven initiated its maiden drilling program at its La Mina project last summer (see press release dated July 27th, 2010). The first five holes collared at the La Cantera prospect by Bellhaven were reported in the September 9th, December 13th, 2010, and January 24th, 2011, press releases. The first four holes drilled at the second prospect, the Middle Zone, were highlighted in the October 12th, November 2nd and 17th, 2010, press releases. This press release discusses the tenth drill hole of the program, DDH-16, collared at La Cantera.
Drill-hole DDH-16 was designed to delimit the southwestern margin of the La Cantera prospect. Starting at a down-hole depth of 12 m (approximately 10-m vertical depth), the hole cut 205 m of mineralized porphyry and breccia averaging 0.91 g/t Au and 0.31% Cu (1.45 g/t AuEq) based on a 0.40 AuEq cut-off grade. Within this intercept occurs the 98-m long high-grade zone containing 1.62 g/t Au and 0.44% Cu (2.38 g/t AuEq) reported above. The high-grade interval is characterized by bornite, together with chalcopyrite and magnetite, associated with K-silciate (potassic) alteration. The mineralized interval was truncated by a late (post-mineral) porphyry stock. Further down hole, DDH-16 cut more gold- and copper-bearing breccia bodies. These rocks host the 68-m intercept containing 0.60 g/t Au and 0.34% Cu (1.19 g/t AuEq) based on a 0.40 g/t AuEq cut-off grade. The true width of the intercepts is approximately 53% of the reported intercept length. Both zones remain open to depth.
Currently Bellhaven is drilling DDH-19 to test the upward extensions of the gold-copper zones cut by DDH-16. Two reconnaissance holes, DDH-17 and -18, drilled to test unnamed prospects located to the north of La Cantera, failed to deliver any significant results.
ALS Colombia Ltda. prepared the drill-core samples, producing the sample pulps in Bogota. 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.
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 (12.3 Moz Au contained in 381 Mt @ 1.00 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), and Quinchia (Batero Gold), as well as large epithermal gold districts such as Marmato (9.8 Moz Au contained in 342 Mt @ 0.90 g/t Au; Medoro Resources).
In mid 2006, AngloGold Ashanti and Bema Gold drilled six holes at 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.
Six other potentially important targets occur proximal to the La Cantera target: Middle Zone, El Limon, El Cafetal, La Virgen, Filo de Oro and El Tanque.
Source: Bellhaven Copper & Gold Inc.