Geoscience Reference
In-Depth Information
POTENTIAL FOR SULFIDE MINERAL DEPOSITS
IN AUSTRALIAN WATERS
TIMOTHY F M
C
CONACHY
Commonwealth Scientific and Industrial Research Organisation
Division of Exploration and Mining, P.O. Box 136, North Ryde
New South Wales 1670, Australia
Tim.McConachy@csiro.au
The world is witnessing a paradigm shift in relation to marine mineral
resources. High-value seafloor massive sulfides at active convergent plate
boundaries are attracting serious commercial attention. Under the United
Nations Convention on the Law of the Sea, maritime jurisdictional zones will
increase by extending over continental margins and ocean basins. For Aus-
tralia, this means a possible additional 3.37 million km
2
of seabed. Australia's
sovereign responsibility includes, amongst other roles, the management of the
exploitation of nonliving resources and sea-bed mining. What, therefore, is
the potential in Australia's marine jurisdiction for similar deposits to those
currently attracting commercial attention in neighboring nations and for other
types/styles of sulfide deposits? A preliminary review of opportunities suggests
the following: (i) volcanogenic copper-lead-zinc-silver-gold mineralization in
fossil arcs and back arcs in eastern waters Norfolk Ridge and the Three Kings
Ridge; (ii) Mississippi Valley-type lead-zinc-silver mineralization in the NW
Shelf area; (iii) ophiolite-hosted copper mineralization in the Macquarie Ridge
Complex in the Southern Ocean; and (iv) submerged extensions of prospec-
tive land-based terranes, one example being offshore Gawler Craton for iron
oxide-copper-gold deposits. These areas would benefit from pre-competitive
surveys of detailed swath bathymetry mapping, geophysical surveys, and sam-
pling to help build a strategic inventory of future seafloor mineral resources for
Australia.
1. Introduction
Submarine deposits of massive sulfides are attracting commercial attention
by exploration and mining companies. This is mainly due to their high
concentrations of gold, copper, zinc, and silver.
1
-
3
These submarine mineral
deposits are no longer scientific curiosities, but are potential new sources
of metals in their own right. This marks a paradigm shift to commercially
driven exploration. As is the case for mining mineral deposits on land, a
sustainable-licence-to-mine the seafloor will be also critically important;
and in this respect fossil “black smokers”, devoid of living chemosynthetic
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