One of the holes, which tested the eastern edge of the Terrazas deposit, cut 138 metres grading 7.46% zinc and 0.38% copper beginning at 22 metres down-hole.
Two other holes, in the Cerro la Verde area, ended in mineralization because the rig was unable to drill deeper. One of these holes cut 111 metres grading 0.28% copper and 6.4% zinc; the other hit 138 metres grading 0.36% copper and 3.83% zinc. The holes will be deepened.
One hole, drilled to twin a previous reverse-circulation hole, also ended in mineralization at 100 metres after cutting 42 metres grading 0.33% copper and 4.5% zinc. A second, adjacent hole, no. 11, continued through the mineralization to a total depth of 318 metres.
Assays are pending for hole 11. However, oxide mineralization was cut, followed by massive sulphide zones (pyrite, sphalerite and chalcopyrite) at depths below 300 metres.
Four holes, two of which tested the northwestern margin of the skarn deposit, failed to hit significant mineralization.
In 2002, the measured and indicated resource in the garnet skarn was estimated at 79.5 million tonnes grading 0.3% copper and 0.4% zinc.
A prefeasibility study in 2002 suggested a mine life of 11 years at an annual production rate of 39.7 million lbs. cathode copper and 59.5 million lbs. zinc. Cash costs were pegged at US53 per lb. copper and US34 per lb. zinc.
The north-south rail line between Chihuahua, Mexico, and El Paso, Tex., is about 2 km west of the property. In addition, a high-voltage powerline traverses the area.
Ongoing drilling is attempting to define the resource. A feasibility study should be completed by year-end.
Constellation, through subsidiary Minera Terrazas, is acquiring a 100% interest in the Terrazas deposit from Minera Rio Tinto. The latter retains a 1.5% net sales revenue royalty, which may increase to 2%, depending on the copper price.
Be the first to comment on "Constellation cuts high-grade zinc, copper"