"Hell On Earth" And CSIRO's Going There

In August 2000 Dr Ray Binns from CSIRO will set sail in a world-first expedition on JOIDES Resolution, a specially equipped scientific drilling vessel operated by the renowned international Ocean Drilling Program (ODP).

He has been appointed co-leader of the first ODP expedition to probe the depths of a massive undersea ore forming system active near Papua New Guinea- the kind that probably gave rise to some of Australia's famous giant mineral deposits such as Broken Hill, Mount Lyell and Mount Morgan.

"The site has attracted world attention because rich deposits of copper, gold, zinc, and silver are forming before our eyes, the way ore bodies we mine today may have formed many millions of years ago," says Dr Ray Binns of CSIRO Exploration and Mining.

The minerals are being forced up through fractures in the seafloor, carried from the bowels of the earth by hot, acidic volcanic fluids.

"By drilling nearly one kilometre into the seabed we expect to find out where these fluids come from and which minerals they deposited on their journey up to the seafloor," says Dr Binns.

Dr Binns considers it possible that Australia still harbours huge undiscovered silver-lead-zinc or copper-gold deposits that formed below ancient oceans as much as two billion years ago, on the same scale as the Broken Hill orebody. The knowledge gained from the ocean drilling project could help to find them.

Operating in water up to 2200 metres deep, the research team will drill core samples from a hydrothermal site in the Bismarck Sea, north of Papua New Guinea, discovered in 1991 by the CSIRO research vessel Franklin.

"This will be the first time anyone has drilled into such environments," says Dr Binns. “For that reason the expedition will use new techniques and equipment. Instead of employing the usual procedure of lowering instruments into a hot and unstable hole after it has been drilled, the team will measure the physical and chemical properties of the walls of the drill hole with instruments mounted directly at the drill bit. This means measurements can be taken during the drilling process,” he says.

Costing $90M a year to run, the Ocean Drilling Program is the premier international earth science research program exploring the dynamics of the earth's interior. Australia is part of a 22-nation partnership in this scientific exploration of the seafloor. Each research expedition, or leg, lasts two months and costs $10-12M.

The Australian Geological Survey Organization, the Australian Research Council, 14 universities, and CSIRO contribute Australia's $1.5M membership to ODP.

More information: Julian.Cribb@nap.csiro