Odyssey applies geological know-how in Turkey

Fatsa, Turkey — Having determined the mineral potential of its properties near this coastal town on the Black Sea, Odyssey Resources (ODX-V) is attempting to raise funding to renew drilling.

The company came to Fatsa in 1998 and has since placed its Lucky Star zinc prospect on hold in favour of brighter metals at the nearby Altintepe epithermal gold and Kabatash copper-gold-molybdenum porphyry targets. Preliminary drilling was completed earlier this year, and ground exploration continues in prepartion for the next phase.

Altintepe and Kabatash sit in the western end of the Eastern Pontides, a magmatic arc that stretches 200 km along the coast and 80 km inland, where it is cut by the country-wide North Anatolian transform fault. The belt is better known for the Cayeli volcanogenic massive sulphide mine of Inmet Mining (IMN-T), which is near its eastern edge, close to the Georgian border.

Near Fatsa, the belt is divided into three volcano-stratigraphic units: a mid-Jurassic-Cretaceous mafic layer, an Upper Cretaceous intermediate-felsic layer, and an unconformable Tertiary mafic layer. The entire succession youngs to the north and was uplifted in the south, exposing deeper roots, such as Kabatash, which intrudes the older basalts.

Altintepe sits in the middle unit and is the more advanced of the two projects, having been explored in the mid-1990s by Cominco [now Teck Cominco (TEK-T)]. Odyssey has since sunk five of its own holes — three in the main 2G zone and one in each of two nearby virgin targets. All are enclosed by hills and associated with a broad, high-sulphidation epithermal system.

Average grades at 2G varied from 0.36 to 2.72 grams per tonne over 32-94 metres, starting from surface. The results are similar to historic ones, with the best Cominco hole, KD-34, about 50 metres from Odyssey’s first hole, averaging 3.4 grams over 76 metres.

Results from Sinan and the other target were similar, averaging 0.85 gram over 14 metres and 0.34 gram over 12 metres, respectively. Again, mineralization begins at surface.

Gold mineralization is disseminated in altered, silicified and hypogene-oxidized dacitic volcanics. A sub-volcanic dome field acted as the heat engine, and easterly and northeasterly structures, as the feeders. Supergene enrichment only occurs in the first few metres of surface, and gold values drop, and quartz-pyrite veining increases, below the oxidation level.

From a regional perspective, the problem at Atlintepe has been that induced-polarization techniques do not work: pyrite averages 3-4% over the property while quartz-vein structures are too narrow for resistivity to pick up. And satellite imagery analysis is useful only insofar as it highlights the favourable faults, owing to the rugged terrain and thick vegetation cover.

“So you can only trust a geochemical grid survey,” geologist Ender Ozaydin told The Northern Miner on a recent site visit. Indeed, geochemical surveying is what led Cominco to all the known zones, though the major followed up with drilling only to back away from gold exploration altogether. Here is where Odyssey enters the picture.

In its upcoming campaign, Odyssey will drill-test two underexplored prospects before moving to delineation and infill drilling at 2G, Sinan, and the nearby Camliktepe zone. The latter set of holes will be collared on 50-metre centres in order to be incorporated in a scoping study.

Dubbed Seyliktepe and Karakis, the “virgin” prospects are about 1 km to the northwest in a northeast-trending geochemical anomaly. Both are hosted by the prospective dacite unit, which here is twice as thick as at 2G.

In Odyssey’s favour is the fact that local upthrusting during the epithermal event pushed the targets to relatively higher elevations, meaning Cominco’s scout holes came shy of the paleo-topographic level at which 2G formed. The deepest Cominco hole ended in mineralized oxides at 166 metres.

However, grades were relatively lower than those encountered at 2G, with the best hole returning 0.9 gram over 24 metres. Ozaydin accounts this to the latter’s having probably formed near the intersection of the favourable faults, though proximity to the underlying domes may have played as important a role.

For now, Odyssey intends to drill 8-10 holes entailing 1,500 metres, all from the flanks of the hills that enclose the targets. Following that, delineation and infill drilling will be carried out at 2G, Sinan, and the nearby Camliktepe zone.

Ultimately, Odyssey aims to outline enough oxide resources to support an open-pit, heap-leach operation. Toward that end, the company recently tabled an independent resource estimate at 2G and released prelimary metallurgical results that suggest recovery rates in excess of 90% can be expected.

Combined indicated and inferred resources stand at 4.35 million tonnes grading 1.62 grams. The estimate, which is based on a cutoff grade of 0.4 gram, incorporates recent and historic results.

The resource remains open to the west.

Should Odyssey’s plan come to fruition, the junior will assess a low-sulphidation target northeast of 2G, with an eye to incorporating a milling operation. Dubbed Extension Ridge, the zone sits at a lower stratigraphic level than the oxide zones, on the southern edge of a kilometre-wide, east-west fracture zone.

Unlike 2G, gold occurs in quartz-pyrite stockworks and breccias, and oxidation is shallow. Sulfosalts are present, but so is amethyst, lending support to the low-sulphidation descriptor.

“The only problem is the high stripping ratio, which is one reason why Cominco stopped work at Eastern Ridge,” said Ozaydin, though he added that possible extentions to the west and at depth could make up for the waste.

Based on the results of the 15 Cominco holes, inferred resources are pegged at 2.19 million tonnes grading 1.21 grams. The independent estimate is based on a cutoff grade of 0.4 gram.

To earn a 100% interest in Altintepe, Odyssey must spend US$550,000 by May 2004 and US$1.35 million over the following two years. The company also issued 150,000 shares and 250,000 warrants (priced at 35 each) to Teck-Cominco at the time of deal’s close, in early 2002.

Meanwhile, about 25 km to the south, mapping and geochemical samping are under way at the less-advanced Kabatash prospect. Two holes were drilled in the winter, results from which combine with recent surface work to suggest the presence of a copper-gold-molybdenum porphyry deposit.

The first hole returned 232 metres of altered, stockworked and veined granodiorite porphyry. Among the alteration minerals are potassium feldspar, sericite, specular hematite and anhydrite, all of which are readily observable at surface.

“It is clear that this is not an ore-grade hole, but it gives us lots of information in terms of mineralization phases, alteration patterns and lithology,” said Ozyadin.

Gold values exceed 0.1 gram in the first 130 metres, reaching a maximum of 0.32 gram at a down-hole depth of 155 metres. Copper averages more than 0.35 gram over the hole’s entire length, peaking at 2.62 grams, and molybdenum grades are upwards of 0.4 gram.

Hole 2, collared 500 metres to the south, at the edge of a zone of phyllic alteration, passed through 100 metres of prophylitic-altered granodiorite characterized by an assemblage of epidote and chlorite. It was stopped at 106 metres, given the secondary alteration visable in core.

Both holes were angled, so future ones will be drilled vertically to pierce the heart of the porphyry. Road cuts, along which explosive breccia with a pyrite-rich matrix is but one notable structure, are helping to sharpen Ozaydin’s geological picture.

Odyssey owns Kabatash outright.

Subject to regulatory approval, Odyssey will issue 5.5 million units through a non-brokered private placement. The units are priced at 18 apiece. A unit consists of a share and a warrant that can be exercised for a year after the deal’s closing, at 25.

Odyssey also will allocate a portion of the proceeds to its recently acquired Tavsan epithermal gold
project in western Turkey. To earn a 100% stake, Odyssey must issue 75,000 shares and 125,000 warrants (again, priced at 35 each) to Teck-Cominco, as well as spend US$1.3 million over four years.

Teck-Cominco has identified five epithermal zones, pegging one with a resource of 7.89 million tonnes grading 1.15 grams gold. The estimate, which incorporates results from 10 holes, is based on a cutoff grade of 0.5 gram.

The resource does not conform to regulatory standards, so Odyssey is having it independently updated. In the meantime, it has been downgraded to the inferred category.

Mineralization is associated with silicified and oxidized limestones and underlying metamorphosed sandstones. Low-angle thrust faults separate the units.

Teck-Cominco holds back-in rights for 51% stakes in both Altintepe and Tavsan, subject to its spending twice as much as Odyssey. The major can earn another 14% in either by funding a feasibility study.

Rounding off Odyssey’s Turkish exploration portfolio is a joint venture with BHP Billiton (BHP-N). The pair are targeting porphyry targets in the Eastern Anatoloid tectonic belt, in the southeastern part of the country.

Odyssey recently staked the Baskil copper-gold property, about 35 km southwest of the city of Elazig. The property consists of two licences in which several copper silt and satallite anomalies occur in association with shallow intrusive complexes.

BHP can earn a half-interest in the property by funding 65% of the first US$1 million spent on exploration.

A property assessment is under way.