Minerals Report - International Seabed Authority

SUMMARY OF THE PRESENTATION AND DISCUSSIONS ON SEAFLOOR
MASSIVE SULPHIDES DEPOSITS AND THEIR RESOURCE POTENTIAL
Presentation
Professor Peter Herzig, of the Lehrstuhl fur Lagerstattenlehre Institut
fur Mineralogie based in Freiberg/Sachsen, Germany, noted at the beginning
of his presentation that it would overlap in part with Professor Rona’s
presentation, and that his presentation on “Seaflloor massive sulphides
deposits and their resource potential” would reflect the point of view of an
Economic Geologist. He also informed participants that prior to his fifteen
years of experience on seafloor massive sulphides deposits he was a geologist
that specialized in land-based massive sulphides deposits.
Utilizing slides, Professor Herzig reiterated some of the points made
by Professor Rona, showing, inter alia, the principal morphological features of
the modern seafloor: the deep ocean basins with water depths in excess of
5,000m and the occurrence of manganese nodules; sea mount areas of the
Pacific and the occurrence of cobalt-rich manganese crusts deposits, and the
mid-ocean ridge system, comprised of the Mid-Atlantic Ridge, the Red Sea,
the Carlsberg Ridge, the Central Indian Ridge, the Southwest and Southeast
Indian Ridges the East Pacific Rise, the Southeast Pacific Rise and the
Northeast Pacific Rise.
With regard to the mid-ocean ridge system, Professor Herzig noted
that these ridges are to be found across all the major spreading centres of the
world’s oceans, and that with a total length of 55,000 km, the ridge system is
an important morphological feature of the seafloor. He further noted that
ridges also define boundaries, places where new oceanic crusts are being
continuously formed
In relation to crust formation, Professor Herzig informed participants
that rates differed in different parts of the ocean. For example, he noted that
the Mid-Atlantic Ridge is a slow spreading ridge with a spreading rate of only
a few centimetres per year, while the East Pacific Rise, in particular in it’s
INTERNATIONAL SEABED AUTHORITY 145