From
modest beginnings in 1996, research into the mineral potential of New Zealand's
Exclusive Economic Zone has progressed into a major multidisciplinary component
of GNS's recently funded 6-year Mineral Wealth of NZ and its EEZ' Programme. In
excess of $7.5 M of research funding has been expended, plus $10 M leveraged via
collaborations with NIWA (NZ), NOAA (USA), JAMSTEC (Japan), U. Kiel (Germany)
and ANU (Australia), whose scientists have contributed hugely to research
cruises, as well as subsequent analysis and publication. The 1999 NZAPLUME I
cruise was the first research expedition to systematically locate, and
chemically characterise, submarine hydrothermal venting associated with arc
volcanoes of the southern part the Kermadec intra oceanic arc system. This was
followed by the 2002 NZAPLUME II and 2004 NZAPLUME III cruises to the mid- and
northern-sections of the Kermadec arc, respectively. Combined, these cruises
have surveyed 1300 km of the volcanic chain (from Whakatane to Monowai),
including 34 major volcanic centres. Together with concurrent surveys in the
Tonga arc, this is now the longest
continuous stretch of intra oceanic arc to be surveyed for hydrothermal
emissions. Most of the volcanic centres are characterised by simple cones
although 30 per cent contain caldera complexes, and compositions range from
basalt through to rhyolite. Massive sulphide mineralisation has been recovered
from several volcanic centres in the southern Kermadecs (Clark, Rumble II West
and Brothers), suggesting the existence of significant Au and base metal bearing
deposits along the arc front.