Lundin Mining Corporation (TSX:LUN)(OMX:LUMI) has announced the discovery of a new copper-rich massive sulphide deposit at its 100% owned Neves-Corvo mine in southern Portugal.
Surface exploration drilling near the Neves-Corvo mine has discovered a sixth deposit to add to the Neves, Corvo, Graça, Zambujal and Lombador sulphide deposits. Each of these original five massive sulphide deposits hosts one or more copper-zinc(-tin) orebodies and the discovery of a sixth massive sulphide deposit is a significant event in the history of the mine. This new deposit has been named the Semblana deposit and is located only 1.3 km northeast of the Zambujal orebody in an area which has not previously been drilled.
Neil O'Brien, Senior Vice President of Exploration and New Business Development for Lundin Mining commented, "The last discovery of this significance at Neves-Corvo was the initial discovery of the Lombador massive sulphide deposit 22 years ago."
"In the past 5 years exploration drilling has successfully defined more than 40 million tonnes of zinc resources at Lombador. The discovery of the Semblana deposit, however, demonstrates that new high-grade copper deposits of the calibre of the original discoveries can still be found at Neves-Corvo," Dr. O'Brien said.
The Semblana area was targeted on the basis of coincident gravimetric and ground electromagnetic geophysical anomalies and extrapolation of favourable geology down dip of the Zambujal orebody and along strike of the Corvo orebody. Three widely spaced initial holes were drilled, intercepting weak sulphide stockwork mineralization containing anomalous copper and tin values.
Borehole electromagnetic ("BHEM") surveying was performed in each of these three drill holes, resulting in the identification of a strong off-hole conductor. Hole SO48 was the first to test this conductor and intercepted a thin bed of zinc-bearing massive pyrite underlain by pyritic stockwork type sulphides, thereby confirming the source of the geophysical anomaly as concentrated sulphide mineralization.
Hole PSL48, located 180 metres along strike to the northwest of the intercept in SO48, intercepted 67 metres (from 883 to 950 metres) of strong copper/zinc-enriched massive and stockwork type sulphides returning a best assay interval of 36.5 metres grading 1.4% copper, including 6.0 metres grading 3.4% copper and 2.6% zinc.
Subsequent holes have intercepted additional thick massive and stockwork type sulphide intervals, including 4.0 metres grading 4.6% copper in hole PSL48A-1 and 21.0 metres grading 4.2% copper in hole PSK50-1. These intersections are located respectively 100 metres northeast and 230 metres north of PSL48.
Importantly, in addition to the high copper grades intercepted in holes PSL48, PSL48-1 and PSK50-1, each of these drill holes has encountered concentrated values of tin (e.g., hole PSL50-1 contains a 3.0 metre interval averaging 1.2% tin) suggesting that the Semblana deposit is geologically similar to the high-grade Corvo orebody located approximately one kilometre to the west.
Assays are pending for two additional massive sulphide and stockwork intersections from holes PSJ46 (300 metres northwest of PSL48) and PSI50 (400 metres north of PSL48).
Highlighted drill results are summarized below:
Exploration drilling has currently outlined an area of at least 600 metres by 250 metres of massive sulphide + stockwork mineralization in 7 drill holes. This new deposit remains open in almost all directions and appears to be almost flat-lying. Drill intersections shown above are interpreted to be true thicknesses. Additional BHEM surveying indicates that the conductive sulphide mineralization has significant size potential. There are currently four drill rigs delineating the extent of this new discovery.
Sampling and Analytical Protocol
NQ sized drill core was logged, cut in half with a diamond saw and sampled by Company personnel at its facilities at the Neves-Corvo mine. Mineralized intervals are analyzed for a suite of elements including Zn, Cu, Pb and Sn at the Neves-Corvo laboratory using XRF methods.
Bob Carmichael, P.Eng., General Manager, Resource Exploration, is the Qualified Person as defined by National Instrument 43-101 and has reviewed and approved the technical information contained in this release.
Source: Lundin Mining Corporation