Minerals Report - International Seabed Authority

scientific journal "Nature". The subject of the paper was the first deep-sea
polymetallic sulphides deposit making the connection between the Red Sea
and the deep ocean. The paper showed that as an ocean basin continues to
open, about one of these submerged sea floor spreading centres; the deposits
continue to be formed.
Continuing his presentation, Dr. Rona said that the next year in 1979,
the American submersible ALVIN, made a dive at the same location. He
noted that the implication of these polymetallic massive sulphides deposit
was that they are deposited from very hot, hot springs, but that nothing was
observed on the dives with the CYANA in 1978. He pointed out that an
objective of the dives in 1979 with Mexicans, French and Americans working
together was to look for the hot springs. He said that the expedition landed in
the normal volcanic rocks of the deep sea floor and started the normal deep
ocean sea floor that was paved with volcanic rocks. Dr. Rona said that within
kilometres of those curious green mounds, the expedition came upon a
chimney, several metres high, billowing clouds of black smoke. The
expedition members stated that "This looks like a factory smoke stack", thus
the name "Black Smoker". The black smoker he informed participants, is
composed of mineral particles that crystallize from the hot springs. He
pointed out that the expedition was unable to take temperatures or samples
and thus its members were fortunate to come back alive because the plastic
windows on the submersible could have melted in the temperatures to be
found at the site. Dr. Rona said that the expedition returned a year later with
new heat tolerant instrumentation found out that the temperatures went up to
about nearly 400 degrees Celsius. The expedition also found that the
structures were mineralised chimneys deposited from the hot springs that
flowed up through them. The cavities inside the chimneys were lined with
bright crystals of sulphides of iron and copper- iron and copper sulphides and
that these chimneys grew up to tens of metres high, and then simply collapsed
and toppled over, accumulating an apron of polymetallic massive sulphides
around their base.
Dr. Rona remarked that another unexpected surprise was the
discovery of a dense and spectacular biological community at 2000 metres
down in pitch darkness and shut off from the light of the sun. An oasis of life
was found, not only of life but also of new life forms such as giant tubeworms,
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