Foulden Maar. Photo: Gregor Richardson

Dunedin city councillors will support the preservation of Foulden Maar, and are looking at steps to stop mining there.

Whether to support the retention of the site - a former crater lake home to thousands of 23-million-year-old fossils - was mooted at a council meeting yesterday.

Cr Aaron Hawkins put forward a motion suggesting councillors recognise the significance of the fossil record at Foulden Maar, and support its preservation and protection as a scientific resource.

He also asked the council to commission an options paper ''with urgency'' providing information on how they could give effect to their decision to support it.

Crs Lee Vandervis and Mike Lord did not support the motion, and Cr David Benson-Pope abstained.

However, all other councillors, as well as Mayor Dave Cull, voted in support.

The meeting continued from Tuesday, when paleontologist Associate Prof Daphne Lee spoke of the importance of the site, near Middlemarch.

Council chief executive Sue Bidrose said yesterday staff were already investigating whether the second-generation district plan could be altered, to make Foulden Maar an outstanding natural feature.

The letter sent by Mr Cull to the Overseas Investment Office in support of the mine had been set aside, and the office now regarded the council as neutral, Dr Bidrose said.

During the meeting, Cr Hawkins made comparisons between the mining proposal and the proposal for an aluminium smelter at Aramoana in the 1970s, halted by the Save Aramoana Campaign.

Cr Vandervis said he accepted if the site was mined, a large proportion of fossils - which were ''of enormous interest'' - would be lost.

However, he considered the climate change record of the time was less significant, and said people could already research the climate at different periods in time on the internet.

He wanted the council to work with the owners to allow more ''careful economic development''.

Mr Cull said private ownership was never absolute and Associate Prof Lee had stated scientific research and commercial development of the site were incompatible.

elena.mcphee@odt.co.nz