Prospector confident of rich sea deposits

Neptune Minerals - newly listed on the London Stock Exchange yesterday - plans to mine seabed sulphide deposits around New Zealand containing high levels of metals such as copper, zinc, lead, silver and gold.

The company, which expected to be worth 20 million ($52 million) after listing on the Alternative Investment Market, wants to spend 10 million drilling off the coast of New Zealand, starting before the end of the year. Neptune Minerals has licences covering 33,000 sq km offshore, with applications to boost that to a total of 120,000 sq km.

Neptune's chief executive, Australian geologist Simon McDonald, told the Daily Telegraph newspaper: "This will provide the financial platform for our next stage of development towards the commercial recovery of massive sulphide deposits from the sea floor.

"The information from this drilling programme will move us quickly towards the identification of a bankable sea floor mineral resource, creating the basis for a new and substantial offshore minerals industry."

Neptune described the deposits of "seafloor massive sulphide", as a new asset mining class which had not yet been commercially developed anywhere else in the world.

Neptune's first mining permit covers the southern part of the Kermadec Ridge north of White Island, but it has also sought rights to more than 90,000sq km further along the ridge towards the Tonga Trench.

The company said rock samples already taken from the seafloor typically had higher metal contents than equivalent deposits mined commercially onshore.

The initial finds were at the Brothers volcano, in 1850m of water, in the Kermadec Arc, northeast of New Zealand.

There are 75 seafloor volcanoes along the Kermadec arc, many of them with hydrothermal vents belching super-hot water with so much dissolved mineral content that they are often called "black smokers".

At temperatures of up to 320C, the fluids dissolve rock as they pass through the earth's crust and deposit the minerals on the ocean floor.

New Zealand is preparing to go to the UN next year to lodge a claim to a continental shelf boundary 50 per cent bigger than the present 4 million sq km of exclusive economic zone.

The claim will cover rights to seafloor minerals on the 2 million sq km of continental shelf outside the EEZ and open up hundreds of billions of dollars worth of mineral and other resources.

- NZPA