"We are hoping laboratory studies in the next few weeks will show that we caught a gold deposit being born," said Dr. Ray Binns of CSIRO, co-chief scientist and leader of the Australian scientific team.

Researchers from Indonesia and Australia aboard the research vessel Baruna Jaya VIII returned to Jakarta last weekend after the first ever search in Indonesian waters for evidence of mineral deposits forming on the ocean floor.

Deep on the flanks of Banua Wuhu, a still-active volcano near the remote Indonesian island, Sangihe, the team found rocks bearing metal sulfide minerals -- rocks that have been altered by the hot volcanic fluids to form minerals that are commonly associated with gold deposits.

Banua Wuhu last erupted in 1919 -- its bubbling summit is now only visible at low tide.

"However, even if we do find high gold contents, it is not likely these deposits on Banua Wuhu could ever be mined in this highly unstable volcanic environment," says Dr Binns.

"The research will, however, give exploration companies further clues to finding ancient equivalents back on land," he says.

The expedition was a major collaborative venture conducted under a research cooperation agreement between the Indonesian Ministry of Marine Affairs and Fisheries (DKP) and CSIRO, with the Indonesian Institute of Sciences (LIPI) as science coordinator. Its aims were to understand how ore bodies formed millions of years ago in the geological past and also to establish whether there might be exploitable mineral deposits in the region.

To top off the expedition, the team made an exciting offshore discovery during the closing hours of the expedition. Virtually in the shadow of the 1,320-meter high active volcano, Gunung Awu on Sangihe Island, at the site marked on the charts as a 58-meter deep shoal, the team discovered a submarine volcano about 1,000 meters high, with a summit crater 530 meters below the surface.

The scientists think this could be the site of a submarine eruption witnessed from Sangihe in 1922, and the data suggests that the top third of the volcano was blown off at the time.

Samples dredged from the crater were very fresh, with a composition known to be associated with ore deposits in ancient volcanic rocks. Unfortunately, lack of time prevented further investigation.

Altogether, the expedition examined fifteen submarine volcanoes in the volcanic chain that extends north from Sulawesi towards the Philippines, seven of which were previously unknown. Most proved extinct with no present day hot spring activity.

Besides seismic surveying and echo-sounding with a sophisticated system that maps wide bands of ocean floor, the team deployed deep-tow video equipment to view the sea bed and an instrument package for detecting mineral "smoke" arising from submarine hot springs. A dredge and a sediment corer were used to collect samples from the sea floor. The sites examined ranged down to 2 kilometers deep.

The expedition also studied the sea floor in Tomini Bay, an almost landlocked basin 2,000 meters deep between the "arms" of Sulawesi, where the volcanic island Una Una erupted destructively in 1983.

Here the team was looking for a different kind of ore-forming environment associated with sediments, a type never before seen on the modern ocean floor. No actual mineral deposits were found, but an enigmatic cloud of white particles was discovered in the seawater column, suggesting the area needs further study.

While in Tomini Bay, the team conducted the first seismic survey of this remote sedimentary basin, which revealed a number of geological structures that are potential traps for petroleum accumulations.

The representative of the Indonesian Ministry of Marine Affairs and Fisheries (DKP) on board the Baruna Jaya VIII, Syarif Hidayat, says that such discoveries are extremely important.

"One day our supply of non-renewable oil and gas on land and in shallow offshore areas will run out, and it is vital that we start now to delineate new sediment basins in deeper waters that could provide future energy resources for Indonesia," he says.

Training of Indonesian scientists in this kind of frontier research was also an objective of the program. A total of 25 scientists from LIPI and other Indonesian institutions, as well as the ship's officers and crew, gained experience in shipboard operations during the two legs of the expedition.

Some will travel to Australia later in the year to join in the laboratory processing of samples and data. The seven Australian participants came from CSIRO and the University of Sydney.

"What we have learned this past month will help us plan future expeditions. We have returned with a wealth of new geological information on the areas we visited," says Dr Haryadi Permana from LIPI, the Indonesian co-chief scientist.

"We look forward to developing even stronger links between LIPI and CSIRO in this area that must ultimately benefit the Indonesian economy."

Australian participation in the expedition and the training program was funded by AusAID, under the Australia-Indonesia Government Sector Linkages Program. - By Jason Major

[Contact: Dr. Raymond Binns, Judy Thomson, Jason Major]

09-Jul-2001