New Zealand's potential trillion-dollar ironsands industry is awaiting clarity from the Government about changes to the foreshore and seabed legislation.

The imminent repeal and replacement of the contentious Foreshore and Seabed Act had created uncertainty around minerals, such as ironsands, Chapman Tripp commercial dispute expert Daniel Kalderimis said.

Ironsands are classified as Crown-owned minerals under the Crown Minerals Act.

Mr Kalderimis said the current Foreshore and Seabed Act did not change ownership of minerals, such as ironsands, to Maori, but it was not "precisely clear" whether that status would change under the new legislation, which was expected to come before Parliament next month.

Ownership of these minerals should stay with the Crown, even if foreshore and seabed ownership was proved by iwi through customary title, he said, but iwi might look to acquire rights to minerals through settlements with the Government.

Attorney-General Chris Finlayson has said he is willing to negotiate directly with iwi.

Any such deals reached between iwi and government would probably require an amendment to the Crown Minerals Act, Mr Kalderimis said. "It's a big step to amend the act. I don't think you can assume it would happen, but it could."

There was a large amount of corporate and iwi interest in the issue, he said.

Crown Minerals estimates New Zealand's future ironsands industry could be worth anywhere between $600 billion and $1 trillion. Ironsands are used in the production of iron ore and steel.

Because most of the ironsand being mined was privately owned, permit revenue figures were not released, Crown Minerals spokeswoman Tracy Dillimore said.

Only a few industry figures are publicly available. In 2009, 585,978 tonnes was produced from the Waikato North Head mine, with the Glenbrook Steel Mill producing about 650,000 tonnes of steel annually from ironsands produced at North Head.

This deposit is estimated to contain 150 million tonnes of ironsands.

In 2008 the Taharoa Iron Sands Business' mine had revenue of about $53m, with all ironsands produced exported.

Now, 10 permits are held that specifically target ironsands, with a further seven being assessed by Crown Minerals.

Of the 10 current permits, three relate to prospecting. Big international miners such as Fortescue Metals through its offshoot FMG Pacific, Rio Tinto and Sinosteel hold permits, along with less well-known players such as Trans Tasman Resources (TTR), Serdicho Developments, and Ironsands Offshore Mining.

Ironsands explorer TTR wants to capitalise on New Zealand's mineral-rich black sands.

It holds prospecting permits which cover 6319sq km of seabed in two areas off the North Island's west coast.

TTR said its permit areas could be expected to produce 5 million to 10 million tonnes of ironsand a year. It has tentative plans for an on and offshore mining operation and onshore steel mill dependent on the results of the prospecting activity.

Managing director Bill Bisset said the industry would work "within whatever rules are promulgated", but it was wary of any retrospective or "reactive" legislation.

- © Fairfax NZ News