Uranium among West Coast treasures

It was revealed this week that a mining survey covering most of the West Coast controversially included some World Heritage sites. DEIDRE MUSSEN reports.

Imagine the outrage if New Zealand started mining uranium.

Not a good look for the Western world's first nuclear-free country.

But plenty of the naturally occurring radioactive metal, used internationally to create nuclear power and bombs, lies under some of the West Coast's most scenic spots.

The region is home to a periodic table of mineral riches. Some are mined but most have been left undisturbed. That may soon change.

A $3 million, two-year aeromagnetic survey, funded by the Economic Development Ministry, is expected to map more clearly where the region's untapped wealth may lie.

The survey covers 16,190 square kilometres, about 70 per cent of the West Coast, and excludes national parks and high-value schedule 4 conservation land, but includes some parts of Te Wahipounamu Southwest New Zealand World Heritage area.

The results will be made public next May, when the ministry will call for tenders from interested prospectors.

A similar survey was done on 13,500 sqkm of Northland, and tenders for exploration permits opened on June 13.

Though the West Coast is known for its coal, gold, greenstone and limestone, it is also a treasure trove of more unusual minerals.

A 2010 mineral resource assessment of the region by GNS Science shows the list also includes antimony, beryllium, tin, lead, zinc, molybdenum, tungsten, titanium, magnesium, zirconium, chromium, copper, and platinum group metals such as platinum, palladium, iridium, rhodium, osmium and ruthenium.

Most of the country's uranium deposits can be found in sandstone-type deposits in the lower Buller Gorge and Pororari River, both popular West Coast tourist spots.

It has also been recorded in gold dredge concentrates in Westland's Taramakau River and Gillespies Beach.

The GNS report says uranium was discovered on the Coast in 1955 in the lower Buller Gorge, leading to an "exploration rush" into the 1960s.

However, the low-grade deposits proved uneconomic and were never mined, despite several companies restarting prospecting in 1966, including some from overseas.

The West Coast's ilmenite- rich black sands are another mineral resource to attract much attention in recent years.

The GNS report says ilmenite, a titanium mineral, is found at intervals offshore along the West Coast's 320 kilometre length.

The largest deposits are near Barrytown and Westport.

Two weeks ago, the ministry's New Zealand Petroleum and Minerals approved Ironsands Offshore Mining Ltd's application for a two-year prospecting permit for 8697 sqkm of the West Coast's seabed.

It extends from the low- water mark west 12 nautical miles, excluding protected areas such as proposed marine reserves.

The New Zealand-registered company, which has shareholders from New Zealand, Singapore, Australia and Malaysia, says its main focus is to use it to produce merchant pig iron, and it will dredge offshore.

It has been granted exclusive rights to search for ilmenite, ironsand, garnet, platinum group metals, rare earth metals and zircon.

Previous prospecting permits for the same area had been granted to other companies, which focused mainly on gold.

The GNS report says platinum group metals are common nationwide but they have never been mined or fully explored.

They have been recorded in Westland's pounamu zone, washed down nearby rivers into the offshore sediments, it says.

Another mineral mined earlier on the West Coast is antimony.

Used to harden soft metals like tin and lead, it was exported in the 1880s after its discovery in 1879 at the southern end of the Paparoa Range.

About that time, 10 tonnes was shipped to England but proved disappointing, the report says.

An area nearby, the Croesus Knob Reef, was also found to be rich in antimony but was never harvested, as was an area near Reefton.

Magnesium, as magnesite, was produced in the Nelson area from 1940s until 1981 for use as a fertiliser.

The GNS report says it is present in Westland but not mined in the region to date.

Beryllium, as beryl, has been found near the West Coast township of Charleston and in the lower Buller Gorge, but has not been mined.

Exploration for tungsten, a hard, brittle metal used for creating stainless-steel alloys, has been under way near Reefton since 2007.

Molybdenum has been explored from the 1960s to early 1980s, mainly around Karamea, but never productively mined.

Minerals West Coast, a charitable trust aiming to improve co-operation between those involved in the region's minerals sector, believes its potential huge wealth is ripe for discovery.

That does not mean uranium mining is likely to start soon.

New Zealand's 25-year-old anti-nuclear laws prevent uranium production "in the near future", says the ministry.

Its Minerals Programme for minerals also bans its prospecting, exploration and mining.

Grey District Mayor Tony Kookshorn believes the region, which he calls the "jewel in the crown", will be the nation's saviour from the economic doldrums.

But conservation groups are steeled to fight for the region, home to about a quarter of the nation's public conservation land.

Only time will tell who will win.

The Press