Bear Creek expands Corani pawprint

Results are in hand for another 26 holes at Bear Creek Mining’s (BCM-V, BCEKF-O) Corani silver project, situated high in the Andes of southern Peru, and the potential for expansion of the 250-million-oz. resource looks good.

The first stepout hole to the east of the Corani Este resource area in the latest batch of drill results confirms that the silver mineralization extends beneath the post-mineral cover.

Two trends of structurally controlled silver-rich mineralization — Main Corani and Corani Este — are exposed along separate ridges at the bulk-tonnage prospect, more than 500 metres apart. Separated by a small drainage valley, the Corani Este zone lies directly across from the past-producing Minas Corani area. Corani Este has emerged as the highest-grade resource of the three zones.

Angled at minus 70 into Corani Este from new access along the ridge top, Bear Creek intersected 76 metres of 99.3 grams per tonne (or 2.9 oz. per ton) silver, 0.8% lead and 0.3% zinc, including a 30-metre section averaging 157 grams (4.6 oz.) silver, 0.9% lead and 0.7% zinc, beneath 112 metres of post-mineral cover in hole 67. The newly completed hole was aimed back towards hole 27B, which cut 148 metres of 99.5 grams silver (2.9 oz.), 0.8% lead and 1.2% zinc at a minus 50 angle into the hillside, including a 22-metre section grading 199 grams silver (5.8 oz.) and 0.7% lead.

Corani Este is at least 150 metres wide on this section and still wide open. Bear Creek has swung the rig around and is stepping further out to the east with hole 67A. In addition, recent drilling is systematically pushing out the northern boundary of Corani Este by hitting mineralization 125 metres beyond the previously defined resource limits. Like the Main Corani trend, Corani Este disappears to the north under a younger post-mineral volcanic cover.

The mineralization occurs along a series of north to northwest-trending, vertical to west-dipping structures in association with veins, breccias and stockworks. The host rocks are a Tertiary-age tuffaceous volcanic unit that overlies a Paleozoic sedimentary rock sequence. The mineralized volcanics are, in turn, overlain by post-mineral volcanic tuffs, which are generally flat-lying to gently dipping and occupy much of the volcanic section at the north end of the property. There is evidence of both classic epithermal textures and polymetallic metal associations of more deeper mesothermal-type mineralization.

Drill-hole fence 59 is more than 70 metres beyond the northern limits of Corani Este’s inferred resource, estimated in March at 42.2 million tonnes grading 88.3 grams (2.58 oz.) silver, 1% lead and 0.73% zinc, containing almost 120 million oz. silver. The resource area of Corani Este is defined by drilling over a strike length of 800 metres and a width of 100 to 150 metres, remaining open to the north and to the east.

Each fence is typically composed of three holes positioned from the same site at different angles. Hole 59A was drilled to the east at minus 50 and intercepted 138 metres averaging 78.1 grams (2.3 oz) silver, 1% lead and 0.5% zinc, including an upper 18 metres of 169 grams (4.9 oz.) silver and 0.9% lead. Steepened to minus 70, hole 59 cut 110 metres of 80.3 grams (2.3 oz.) silver, 1.1% lead and 0.5% zinc, including a 14-metre section grading 132 grams (3.8 oz.) silver, 2.4% lead and 2.7% zinc at the very bottom. The rig was swung around and aimed to the west at minus 80, hitting 60 metres of 47.8 grams (1.4 oz.) silver and 1.1% lead from surface, followed by another 20 metres of 43.9 grams (1.3 oz.) silver, 0.8% lead and 0.4% zinc from 100-120 metres in hole 59B.

In the next fence of holes, 125 metres beyond the edge of the resource, hole 64 was collared at minus 50 and aimed to the east, intersecting 86 metres averaging 57.8 grams (1.7 oz.) silver and 1% lead from surface, including 126 grams (3.7 oz.) silver, 1.4% lead and 1.2% zinc across the last 10 metres. A second intercept between 110 and 120 metres down-hole ran 146 grams (4.2 oz.) silver, 3.6% lead and 5.6% zinc across 10 metres.

Hole 64A was steepened to minus 70 and hit 112 metres grading 75.6 grams (2.2 oz.) silver, 1.2% lead and 0.5% zinc, including 16 metres of 159 grams (4.6 oz.) silver and 1.1% lead in the lower half of the hole. Hole 64B was aimed in the opposite direction and angled at minus 80, intercepting 118 metres of 36 grams (1.1 oz.) silver and 0.4% lead.

SRK Consulting used the results of 83 diamond-drill holes and 25 surface trenches completed through to mid-February of this year to calculate a 44.5-million-oz. measured and indicated silver resource in the Main Corani zone grading 49.6 grams (1.44 oz.) silver. Additional inferred resources in the Main Corani, Corani Este and Minas Corani zones total 205 million oz. averaging 72.9 grams (2.12 oz.), based on a silver cutoff of 20 grams.

Adding ounces

Bear Creek has since completed an additional 33 holes on the three mineralized zones as it focuses on adding ounces by chasing the northern boundaries of Minas Corani and Corani Este. In addition, 40 holes are now completed from 13 drill fences on a new emerging gold zone further south, which is not part of the resource estimate. A resource update is expected in July.

The gold zone occurs along a primary north-south-striking structure that extends for about 1 km. Recent drilling returned a near-surface 12 metres of 4.8 grams gold and 89.3 grams silver in hole 60B. To date, 28 holes targeting the main structure show an average grade of 2.4 grams gold and 44.6 grams silver across an estimated width of 14.8 metres.

The Main Corani zone, including the formerly producing Minas Corani area at the north end, extends over a strike length of 1,500 metres. The original drilling at Main Corani was relatively closely spaced; as a result, a portion of the deposit contains a measured and indicated resource of 27.9 million tonnes grading 49.5 grams (1.44 oz.) silver, 0.79% lead and 0.23% zinc. An additional 8.5 million tonnes grading 34.5 grams (1 oz.) silver 0.51% lead and 0.37% zinc is inferred.

Recent drilling has encountered multi-ounce silver-lead mineralization in both the footwall and hangingwall to the Main zone, including hangingwall higher-grade feeder-type structures. These structures are hidden under a thin veneer of talus. One intercept ran 291 grams (8.5 oz.) silver, 1.7% lead and 0.5% zinc across 6 metres in hole 66.

Recent trenching has exposed the favourable volcanic unit containing strong barite breccias and stockwork veining between the Main Corani and Minas Corani resource areas. According to Bear Creek, trench 27, which yielded 60.1 grams (1.8 oz.) and 0.75% lead across 24 metres, begins to connect the mineralization between the two zones.

Minas Corani

Minas Corani contains an inferred resource of 36.9 million tonnes of 64.4 grams (1.88 oz.) silver, 1.19% lead and 0.46% zinc, or 76 million oz. silver. Exploration drilling is continuing to step out under the post-mineral cover on the northern end of the zone. The first fence of four holes was collared about 35 metres beyond the resource limits. Angled at minus 70 to the west, newly completed hole 51B intersected 66 metres averaging 100 grams (2.9 oz.) silver, 1.9% lead and 0.5% zinc, including a higher-grade 24-metre interval of 168 grams (4.9 oz.) silver and 1.6% lead, under 36 metres of post-mineral tuff.

Another fence of holes was collared almost 500 metres out to the west, representing a significant stepout across the post-mineral cover. Aimed minus 50 eastward, hole 65 intersected 106 metres averaging 60.4 grams (1.8 oz.) silver, 1.5% lead and 0.3% zinc starting 2 metres from surface, including a lower zone grading 110 grams (3.2 oz.) silver and 3.8% lead across 18 metres. Steepened to minus 70, hole 65A encountered 66 metres of 67.8 grams (2 oz.) silver, 0.9% lead and 0.3% zinc, beginning 22 metres down-hole.

Several mineralized structures and barite breccia bodies are believed to underlie the extensive 500-metre wide target area covered
by the younger post-mineral tuffs. Four drill rigs are currently turning on the project; a scoping study is due mid-year.

Bear Creek optioned the 26-sq.-km property from Rio Tinto (RTP-N) in January 2005 and is earning a 70% interest by making a series of escalating payments totalling US$5.4 million over three years.

In the meantime, the start of the long-awaited drill program to test the Santa Ana silver prospect, several hundred kilometres south of Corani, has been delayed until June while Bear Creek goes through the permitting process.