Prospecting by partners
Surface trenching exposed the 1-metre-wide dike, dubbed Brauna 17, just 50 metres from the Itapicuru River. It strikes in an east-west direction, roughly perpendicular to the northwesterly trending kimberlite dike system that hosts the Brauna 3, 4 and 7 kimberlite pipes.
The dike is situated in an area referred to as the Garimpo do Bastiao, which was the site of substantial alluvial diamond and gold exploitation during the 1940s and 1950s. Further exploration will aim to determine if the dike was the source of the diamonds recovered by artisanal miners.
Brauna comprises three exploration concessions covering four known kimberlite pipes. The pipes are associated with a swarm of kimberlite dykes that have been traced over around 15 km. The largest is Brauna 3, with a surface exposure of 3 hectares. The dikes range from less than a metre in width to up to 5 metres.
Late last year, three holes tested the Brauna 3 pipe, with hole no. 1 on the south lobe returning 188.95 metres of kimberlite. Hole no. 2 on the eastern margin, a magnetic anomaly associated with the pipe, cut 83 metres of kimberlite with intercalations of granite, while hole no. 3, on the western margin of the pipe, encountered around 25 metres of kimberlite, with granite intercalations followed by granite.
Two angled holes are currently being sunk to determine whether the north and south lobes of the Brauna 3 pipe are connected. Hole 4 is currently cutting kimberlite at a down-hole depth of 93.7 metres; hole no. 5 has so far cut kimberlite between 13.65 metres and 43.2 metres downhole.
Brauna 3 is reported to have previously yielded diamonds. In 2000 and 2001, a local farmer recovered 250 diamonds totalling 372.9 carats from colluvial gravels and soils excavated immediately downslope from the pipe. The stones are reported to range in size from 0.2 carats to 15.5 carats, with an average stone size of 1.49 carats.
The partners also say that a sample derived from an 8-metre-deep pit into the kimberlite pipe itself reportedly yielded a 3.55-carat diamond.
Vaaldiam plans a mini-bulk sampling of the property’s pipes and dikes during the second quarter.
Brauna is held 60% by Vaaldiam, with Majescor owning the balance.
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