Geoscience Reference
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vent fauna and abundant biodiversity, may offer more suitable targets for
sustainable commercial exploitation. It also means that fossil deposits in
other geological settings on the seabed may warrant attention in the future.
The aim of this contribution is to provide an initial analysis of concep-
tual prospectivity within Australia's seabed for sulfide mineral deposits.
While the analysis is not exhaustive, it is hoped that it might act as a cat-
alyst to initiate surveys utilizing detailed swath bathymetric mapping, side
scan sonar imagery, geophysical methods such as magnetics, gravity and
resistivity, dredging and coring to test various hypotheses and if successful,
ultimately increase Australia's inventory of seabed mineral resources.
2. Setting of Seafloor Massive Sulfide Deposits
Since the discovery of “black smokers” at 21 N on the East Pacific Rise in
the late 1970s, 4 research-driven exploration has discovered mineral deposits
actively forming at hydrothermal vents related to submarine volcanism in
every major ocean basin and divergent plate margin on Earth. 5 , 6 Sites of
equivalent activity at convergent plate margins such as those found in island
arcs and backarcs are well documented, particularly in the western and
southwestern Pacific region, for example, at Sunrise in the Izu-Bonin arc
south of Japan, at PACMANUS in the Manus back arc of Papua New
Guinea and along the Kermadec arc in New Zealand. 7 - 9
If Australia's recent lodgment of revised maritime boundaries with
the UN Commission on the Limits of the Continental Shelf in November
2004 is accepted, it will have one of the world's largest maritime jurisdic-
tion of 14.41 million km 2 , or slightly more than half the total land area 10
(Fig. 1). Accordingly, Australia has a commitment to manage this juris-
diction, including nonliving resources such as seabed mineral resources.
Although no active spreading centres or associated sulfide mineral deposits
are presently known within its maritime boundaries, this does not mean
that sulfide deposits are absent on or in Australia's seabed.
In the following sections, geological settings are examined which are
considered to have potential to host certain types of sulfide deposits. Sub-
merged extensions of mineralized land terranes are considered as well.
3. Fossil Island Arcs and Back Arcs
The SW Pacific consists of a number of remnant and active back-arc basin
and volcanic arc systems which formed as a consequence of Australia-Pacific
plate convergence commencing in late Cretaceous and continuing to the
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