Ivanhoe extends Far North Oyu zone

Vancouver — Geophysical surveying of the Turquoise Hill copper-gold project in Mongolia indicates that the Southwest, Central and Far North Oyu zones are all part of one mineralizing system.

Ivanhoe Mines (IVN-T) reports that the induced-polarization (IP) survey delineated a continuous anomaly some 4.5 km long. The linearity of the anomaly implies significant structural control on the mineralization, and the fact that it is S-shaped suggests a major zone of dilation. The peak of the chargeability at the mid-point of the anomaly is centred on the Central Oyu zone and may represent the centre of dilation.

“The IP anomaly and our recent drilling show that the gold and copper mineralization we have discovered so far is controlled by a single major structure,” says Exploration Vice-President Douglas Kirwin. “Our latest data suggest that the extent of the known mineralization may be substantially increased with additional drilling along the extent of this major structure.”

Recent drill results have almost doubled the size of the Far North zone to 1 by 0.4 km, down to depths of 400 metres.

Also, drilling in the northeasterly portion of the Far North deposit intercepted an increased density of quartz veining, suggesting proximity to an intrusive source. This zone could extend for another 900 metres to the north and may connect with the Central zone, which lies 750 metres to the southwest. The drill results include three holes that tested the northeastern strike extent of the zone.

Hole 319 was collared 100 metres north of hole 310 (368 metres grading 2.46% copper and 0.23 gram gold per tonne) and cut 456 metres grading 1.58% copper and 0.12 gram gold. Included in this section was a higher-grade portion running 2.19% copper and 0.17 gram gold over 276 metres.

Moving 100 metres northeast, hole 327 returned 368 metres grading 1.5% copper and 0.08 gram gold, including 82 metres of 2.85% copper and 0.14 gram gold.

Hole 344 was drilled 100 metres to the northeast and reportedly hit strong mineralization. Results are pending.

Ivanhoe has rigs turning on the southwestern portion of the IP anomaly, which extends south from the Far North zone toward the Central zone.

A new resource estimate for Turquoise Hill, based on all the drilling completed by the end of 2002, is being calculated. The study will include 55 holes drilled at 100-metre spacings at the Central zone, 38 diamond-core holes at the Southwest zone, and 12 holes at 100-metre spacings, in addition to holes drilled by Ivanhoe in 2001 and earlier work by previous owner BHP at the South zone.

The Southwest zone hosts a porphyry gold-copper deposit containing 13.8 million oz. gold and 3.1 million tonnes copper in an inferred mineral resource of 821 million tonnes grading 0.52 gram gold per tonne and 0.38% copper. This calculation is based on a cutoff grade of 0.3% copper-equivalent. The estimate was prepared by AMEC E&C Services in accordance with Canadian regulatory requirements.