Phosphate field on Rise 14M tonnes

Press, 31 January 1979, Page 1

Phosphate field on Rise 14M tonnes

An area of phosphate reserves in 400 m of water off the east coast of the South Island has been technically assessed at 14M tonnes, of sufficient quantity to attract overseas offshore mining companies.

A marine biologist in the Oceanographic Institute of the D.S.LR. in Wellington (Dr D. J. Cullen) said that while there were known phosphate reserves on the Chatham Rise, it was necessary to establish a technical assessment of quantities. ‘‘One comparatively small area alone will yield 14M tonnes; New Zealand imports IM tonnes of phosphate each year,” he said.

Two types of dredging were considered feasible, Dr Cullen said. One used suction, and the other pumped air into one pipe to force the phosphate up another pipe. Scattered among the rock phosphates is a known uranium field, from which 689 samples are being assessed by the D.S.LR. and West German mining interests. “We are slowly working our way through our half of the "samples,” said Dr Cullen. He does not expect any difficulty in recovering the phosphates. Extensive recovery of manganese nodules had been achieved in water depths of 4000 m and 5000 m. “Our deposits are

in much shallower water depths,” he said. The West Germans had shown initial interest, but would not necessarily be the only ones to mine the materials. “We don’t have the shipping facilities, so we would have to collaborate with somebody else,” Dr Cullen said. It. is believed that overseas interests require a reserve quantity while wider fields are probed, and the 14M tonnes already established is a large amount by world standards.

Some of New Zealand’s phosphate supply areas now face a severely limited life, but Dr Cullen doubts whether any largescale recovery off the east coast of the South Island will occur for at least 10 years.

“Because of the size of the potential areas it will

be a long-term project,” he said.

Nauru, Ocean Island, and Christmas Island had limited supplies, but the Middle East was one of many areas in the world rich tn phosphate.

Dr Cullen said that alternative supplies were believed to exist in Queensland, but the areas had closed completely. The price of a supply from the Middle East is causing concern, but some Government sources see prospects for a deal with the Middle East based on the import of phosphates from the area in exchange for New Zealand meat. “We would have complete control over the phosphate on the Chatham Rise and the question arises whether we should get on and use it," Dr Cullen said.