OPERATION FOCUS- CASCAVEL_proof 23/08/2016 09:31 Page 4
OPERATION FOCUS
Mining teams continue to encounter
significant visible gold from stoping in initial
mining areas. Spectacular visible gold from Slot
Raise 2, on Level 1 North was also evident in the
next slot raises opened on this level. Material
from these stopes will be blended with lower
grade stopes for processing in the first few
months of production following commissioning.
This high-grade ore shoot continues to be
evident in the Level development and slot raises
immediately below Level 1 North and all ore
shoots show excellent down plunge continuity in
mine development.
All the slot raises opened in the Southern
Levels of the mine have also been classified by
mine geologists as high grade. Given the tenor of
the mineralisation in the southern portion of
Cascavel, an internal ramp (Ramp 1) has been
advanced from Level 1 South towards Level 2
South, to allow for earlier stoping from the
southern portions of the mine than was
previously scheduled.
A drill program for mine planning purposes
has been confirmed and will commence in the
September quarter. The aim of the 4,000 m
program is to better define the structural
continuity of mineralisation beyond the current
limits of the mine (both along strike to the north
and south and down-plunge). Detailed sampling
along the drill holes will also be conducted to
define different mineralised veins inside the ore
horizon as multiple veins have been observed
inside the mine drives and stopes.
Gekko Systems plant
Visible gold has also been observed in all central
slot raises, which connect Level 1 Central to
Ramp 2, with these central stopes also being
classified by mine geologists as high grade
confirmed previous interpretations of the
orientation, structure, continuity and grade of
the mineralisation, with this occurring as a
number of southwest 20° plunging shoots,
between 10 and 20 m wide separated by lower
grade zones of similar width, in an overall
mineralised structure that dips at around 30° to
the west-southwest.
Craighead and Gordon explain that “given the
extremely nuggetty nature of the mineralisation
Orinoco has used panel sampling to define
grades for the mineralisation. This involves
collecting contiguous 0.5 m high ‘panel’ samples
of the mineralisation along both walls of the
development, with each panel being collected
following advance of the development.
“These provide a significantly larger sample
than conventional channel samples, however, are
still, at around 10 kg, considered insufficient in
size to account for the clustering of the coarse
gold – several tonnes would need to be collected
20 International Mining | SEPTEMBER 2016
to give a representative grade. Also, the grade
from the panels needs to be diluted by a factor
of around two to three to provide a diluted
mining grade.”
Nuggetty gold means very large variability in
gold grades over relatively short distances.
A crushing and gravity circuit has been installed
onsite only 300 m from the mine portal at
Cascavel, with a nameplate capacity of 14 t/h.
Gekko Systems designed the processing circuit,
and, says Orinoco, “provides Orinoco Gold with
unsurpassed levels of technical expertise in the
The current mine plan. The blue circle in the upper left shows Slot Raise 2, Level 1 North. The red
circle highlights the area in Level 1 South containing the previously reported drill result iof 1.5 m @
10.8 g/t (CdP_041) and the composite panel sample result of 14.78 m @ 75.36 g/t Au (including 0.5 m
@ 1,230 g/t. The dark grey and green colours are existing development. The Southern zone does not
yet form part of the mine schedule, and development has not yet advanced into the Mestre zone