Tinteiro IOCG is located in the central portion of the Faina Greenstone Belt, 4km to the south-west of Cascavel.
Tinteiro was discovered in May 2013, when Orinoco discovered high-grade silver and base metal mineralisation in the footwall of the Mestre zone and over the hanging wall of the Cuca zone at Cascavel.
Significant silver and base metals assays announced previously from drilling around the Cascavel area include:
- CDP_025: 25.0m @ 39.2g/t Ag: including 3m @ 97.2g/t Ag from 114m
- CDP_031: 4.4m @ 760.3g/t Ag: including 1.05m @ 2,510g/t Ag from 157m
- CDP_014: 4.7m @ 58.6g/t Ag: including 0.85m @ 236g/t Ag from 162m
- CDP_021: 17.6m @ 1,292g/t Ag & 11m @ 0.25% Cu, 16.41m from 101m
Subsequent geological mapping in the Cascavel exploration decline has shown that the high-grade silver and base metal mineralisation is related to the intersection of a series of north-east trending faults and a dolomitic unit in the footwall of the main Cascavel gold structure.
The north-west trending structures offset and therefore post-date the main gold-bearing structure indicating that these are two separate mineralising events potentially separated by millions of years.
In May 2014 rock chip samples confirmed that this mineralisation extended up to 4km away into the Tinteiro prospect, potentially indicating the presence of a large IOCG system.
Orinoco undertook a reconnaissance drilling program at Tinteiro in September 2014, which provided further evidence of a widespread mineralised polymetallic system at Tinteiro. Assays show that the fault zones are mineralised and are indicative of an alteration halo in the upper portions of an extensive mineral system.