Minerals Report - International Seabed Authority

Dr. Hein suggested that based on the nature of ferromanganese crusts
deposits, the initial stages of exploration would be to find extensive, thick,
high-grade deposits. Later stages of exploration would be dedicated to
identifying and mapping the precise group of mineable crusts. For
continuous mapping of deposits, Dr. Hein stated that multibeam echo
sounders, side-scan sonars, and single and multi-channel seismic systems
would be appropriate. Sampling of deposits could be satisfactorily performed
with dredges and corers. Other tasks during exploration would include
bottom video photography, water column sampling, and laboratory analysis
of crusts and substrate for composition and physical properties
Twelve criteria have been developed for exploration for and mining of
cobalt-rich ferromanganese crusts deposits by Dr. Hein and his colleagues at
the USGS. These comprise six regional and six site-specific criteria. The
regional criteria are: (1) large volcanic edifices shallower than 100-1500 meters;
(2) volcanic edifices older than 20 Ma; volcanic structures not capped by large
atolls or reefs; (4) areas of strong and persistent bottom currents; (5) a shallow
and well developed Oxygen Minimum Zone (OMZ), and (6) areas isolated
from input of abundant fluvial and eolian debris. Site-specific criteria are: (1)
subdued small-scale topography; (2) summit terraces, saddles and passes; (3)
slope stability; (4) absence of local volcanism; (5) average cobalt content
greater than 0.8%, and (6) average crust thickness greater than 40mm.
With regard to future research on deep-sea ferromanganese crusts, Dr.
Hein recommended about ten subjects, including, determining the role of
micro biota in the formation and growth of crusts, determining the
oceanographic and geologic condition that produce very thick crusts, and
continue environmental and ecological studies of seamount communities.
6. Impact of the development of seafloor massive sulphides on deepsea
hydrothermal vent ecosystems
Dr. Juniper spoke on the potential impact of the mining of polymetallic
sulphides deposits on deep-sea hydrothermal vent ecosystems. He stated that
hydrothermal vent science is now in its third decade of discovery. He noted
that more than 100 vent sites have been documented along the 60,000 km of
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