Bellhaven Copper & Gold Inc. (TSX VENTURE:BHV) has announced that its third hole (DDH-12) targeting the Middle Zone cut a substantial block of well mineralized porphyry and breccias.
Two mineralized intercepts were recorded:
- 28 m @ 0.61 g/t AuEq starting at 160 m (upper zone), and
- 94 m @ 1.42 g/t AuEq starting at 326 m (lower zone)
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:
"Our third hole into the Middle Zone delivered a significant intercept of 94 m of 1.4 g/t AuEq, thus validating this exploration prospect. At this early stage of exploration, the geometry of the zone is not well known. For instance, we still cannot constrain the width of the zone. It does appear, however, that the Middle Zone is at least 200 m in length and 300 m in height. This represents a good start."
"We recently hired two Peruvian geologists to supplement our exploration staff at La Mina. As well, we are in the process of extending our drilling contract so that we can continue to drill more holes at the Middle Zone and La Cantera. We look forward to reporting additional drill results from La Mina 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 were collared at the La Cantera prospect and reported in the September 9th press release. The first two holes were collared at the second prospect, the Middle Zone, and described in the October 12th press release. True widths for the intercepts from the Middle Zone are currently unknown.
Drill-hole DDH-12 was designed to test an airborne magnetic anomaly over the Middle Zone, coincident with a weak geochemical anomaly in soil and channel samples. The two previous holes, DDH-10 and -11, were drilled along the western edge of this magnetic anomaly to test a stronger surface geochemical anomaly defined by channel samples returning 0.7 g/t Au over a 77-m wide zone. (For a map showing the location of these drill holes, please see the link on page 2 of the press release dated Oct 12th, 2010). In the first 110 m down the hole, DDH-12 cut porphyry and breccias containing abundant pyrite and clay-bearing alteration assemblages. Starting at 110 m, the hole cut porphyry and breccias altered to K-silicate ("potassic") alteration assemblages containing magnetite and chalcopyrite and lesser quantities of pyrite. The first mineralized intercept (from 160 to 188 m) coincides with this package of rocks. A late and barren porphyry stock occurs from 196 to 297 m. Approximately 30 m below the barren stock, a second and richer gold-copper zone appears from 326 to 420 m. This zone is characterized by (1) breccias containing fragments cut by an earlier, "pre-breccia" episode of quartz and quartz-pyrite ± chalcopyrite veinlets, (2) K-silicate altered porphyry, and (3) quartz ± magnetite ± chalcopyrite and chalcopyrite veinlets cutting (1) and (2). It is unclear if these two gold-copper zones were once part of a single zone that was later divided by the emplaced of the late barren porphyry stock.
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 in the text. 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.