Minerals Report - International Seabed Authority

1.3 Resources
The oceanic regions of the world's continental margins are those
areas primarily located in deep water beyond a depth of 2500m. They have
evolved either as rifted continental masses have been moved apart or
modified by converging seafloor and landmasses. Many “continental
shelf” areas adjacent to oceanic islands or ridges have seafloor
characteristics different to those close to large land masses in that they
generally occur in deep-water and on oceanic basement. Consequently
they contain different non-living resource potentials. Although many of
these natural, non-living resources will be common throughout the
world’s oceans, there are significant differences dependent on platetectonic
location, geological history, basement structure and sediment
supply (Kesler, 1994).
Technology developed in recent years has enabled direct
observation and research on the deep parts of the seafloor. There is
already a capability for drilling for oil and gas in water depths beyond
1,500 m, and this is expected to increase as future deep-water prospects are
realised (International Energy Authority, 1996). Similarly, exploration of
the deep seafloor using manned submersibles and remotely operated
vehicles has been highly rewarding scientifically. Since the 1960s,
reconnaissance surveys have had a profound impact on our
understanding of seafloor mineralisation. As a result of academic-led
research, substantial mineral deposits are now known or predicted to
occur on the seafloor in many parts of the world (Gross and McLeod, 1987;
Herzig, 1999, Herzig and Hannington, 2000).
Offshore non-living resource potentials described in this report are
based on a statistical evaluation of known occurrences and reserves, the
geologic environments favourable for their formation, models for
sediment type and thickness, and basement composition. The result is an
assessment of non-living resources. These estimates are based on the
current state of, largely, publicly available information. In many instances
these data are incomplete. Hence these resource estimates are to be
considered as a guide to the relative potential for occurrence only, and not
a definitive statement of the resources or reserves present.
The term “resource” is used here to describe the potential for
materials to occur. It is not, and should not be taken as, an assessment of
INTERNATIONAL SEABED AUTHORITY 670