Sunrise Dam Gold Mine
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Sunrise Dam Gold Mine |
Location: Laverton,
Western Australia.
Product: Gold.
Geological Settings: The
deposit is hosted by the Archaean Norseman-Wiluna
belt, in the
Eastern Goldfields
Province of the Yilgarn
Craton. The deposit falls within the
structurally complex Laverton
Domain, which is characterized by tight
folding and thrusting. A number of other Au deposits lie
within or
near the margins of the Laverton
Domain, including Laverton,
Granny Smith
(this volume), Red October (this volume), Childe Harold,
Lancefield and
Keringal. Most of these deposits are hosted
by metasedimentary
rocks, a distinctive feature of the Laverton
region
relative to
other parts of the Yilgarn
Craton.
Host Rocks: The
host rocks are shallow-dipping interbedded Archaean metasedimentary,
metavolcaniclastic
and
felsic to intermediate metavolcanic
rocks (Newton
et al., 1998). The metavolcaniclastic
rocks are interbedded
with BIF.
In general, they are thick, bedded to massive and fine
upwards.
The BIF units are typically 2-10 m thick and commonly grade
into magnetite-rich
tuffs. A 20-40 m thick mafic intrusive postdates
the metavolcaniclastic
sequence
on the western
side of
Cleo. Quartzfeldspar
porphyries also
intrude the sequence at both Cleo and Sunrise
and,
at Cleo, post-date the mafic intrusive.
Mineralization: The
Sunrise Shear, within the Archaean rocks, controls geometry of
the mineralization
and is thought to have been the main conduit for
Au-bearing hydrothermal
fluids (Newton et al., 1998).
Pyrite replacement
of BIF
accounts for most of the primary mineralization and is well
developed where
the shear zones, parallel to bedding, follow the contact
of BIF
with less competent units. Gold is also associated with quartzankerite-
pyrite veins
and pervasive ankerite-silica-sericite-pyrite
alteration
of intermediate
volcaniclastic
host rocks. Thin quartz-carbonate veins
also host Au, but are mostly located in the Sunrise part of the
deposit.
Supergene mineralization has developed in the weathered bedrock
and in
transported cover in the eastern part of the study area.
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Regional geology and setting of the Sunrise-Cleo Au deposit | (after Newton et al., 1998) |
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