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Tierra
de Oro Gold Zones
(Click
on zone for detailed description)
The Sierra Chanchero intrusive complex
is crosscut by strong three to five kilometre long, north
to northeasterly and north west trending structure zones,
which appear to be complementary tensional fault zones developed
between the northern Fe-skarn boundary and southern contact
shear faults. These tensional faults are commonly the foci
of multi-episodic dyking, hydrothermal alteration and precious
metal mineralization up to several hundred metres wide. Along
the four most prominent structures second order complimentary
east-west and south-easterly trending structures appear to
localise, to a large extent, the principle areas of piquinero
workings i.e. Bella Ester, Fe Skarn, Andacollo, Escondida,
Atacama and Inca.
Mineralization within these alteration
zones consists mainly of structurally controlled, multi-directional
and often closely spaced, auriferous quartz-carbonate-limonite-hematite
(after sulphide) veins, fracture zones and breccias. Numerous
piquinero workings demonstrate the larger "veins"
vary in width from 0.3 to 5.0 metres, are several hundred
metres to several kilometres in strike length and can grade
1 to 2 ounces per ton gold. This is typically the case at
the Fe-Skarn, Andacollo, Escondida and Inca Gold Zones where
the larger veins have been worked extensively on surface and
underground to depths up to 75 metres.
(click on zone label for detail description)
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