Sunday, June 22, 2008
Volcanoes spewed precious minerals!
The discovery came during a sea floor mapping expedition in the region, in part sponsored by exploration companies.
Measuring 50 kilometres wide by almost 4,000 metres tall, the volcanoes are bubbling away at 1,100 metres and 1,500 metres below the surface of the Pacific Ocean, in an area known as the North Lau Basin, between Tonga, Fiji and Samoa.
They are within the Pacific rim of fire, an area of high earthquake activity, and are spewing into the sea black smoke containing precious minerals.
Chief scientist at the Australian National University, geology professor Richard Arculus, was among the discoverers aboard the CSIRO research ship, the Southern Surveyor, and describes the volcanoes as quite remarkable.
"Some of the features look like the volcanic blisters seen on the surface of Venus," he says.
"It provides a model of what happened millions of years ago to explain the formation of the deposits of precious minerals that are currently exploited at places like Broken Hill and Mt Isa," he says.
It may also provide exploration geologists with clues about new undiscovered mineral deposits in Australia.
"These deep-sea features are important in understanding the influences that have shaped not only our unique continent but indeed the whole planet," Professor Arculus says.
CSIRO's Director of Research Vessels, Fred Stein, who was captaining the ship during the discovery, says finding the volcanoes was serendipitous.
"It was a reminder that at the beginning of the 21st century it is still possible, on what is often regarded as a thoroughly explored planet, to discover a previously unknown massif larger than Mt Kosciuszko," he says.
The two volcanoes have been named Dugong and Lobster.
Though they are in a seismologically unstable area, Professor Arculus says the volcanoes are not likely to trigger a Tsunami. The real danger he says is not eruption but rather collapse. Any eruption though would be a hazard for the neighbouring Pacific nations.
The black smoke pouring out of the calderas leaves behined minerals containing lead, zinc, copper and gold.
Professor Arculus says several exploration companies, who were also sponsors of the voyage, are interested in high grade metals and want to mine such underwater volcanoes, with preparations already underway to mine similar sites near Papua New Guinea.