Geoscience Reference
In-Depth Information
Fig. 1. Australia's maritime boundaries showing the areas of extended continental shelf
submitted to the UN Commission on the Limits of the Continental Shelf in November
2004,
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and some areas of sulfide prospectivity.
present.
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-
13
Plate reconstructions and palaeo-age grids for the Western
Pacific margin illustrate a number of back-arc basins associated with active
and remnant volcanic arcs systems including Norfolk Ridge, Loyalty-Three
Kings Ridge, Lau-Colville Ridge, and the Tonga-Kermadec Ridge.
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,
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By comparison with modern volcanic arc and back arc systems, the
Norfolk Ridge and Loyalty-Three Kings Ridge arc-back arc systems in
eastern Australian waters have potential to host submarine Cu-Zn-Au-
Ag massive sulfide deposits. Further work incorporating tectonic models
and observational constraints into 3D mantle convection models is pro-
viding important predictive tools for mineral exploration.
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,
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Zones of
reduced magnetization-often associated with volcanogenic massive sulfide
hydrothermal systems
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are potential geophysical footprints with which to
explore for massive sulfides in this area.
4. Mississippi Valley-Type Deposits
Like volcanogenic copper-zinc deposits, Mississippi Valley-type lead-zinc-
deposits are also an important class of base metal deposit.
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Most occur in
orogenic foreland settings. Bradley and Leach
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have examined deposits in
collisional forelands and suggest that, tectonically, the passive foreland car-
bonate shelf environment of the Banda Arc collision zone off NW Australia
