Dunedin's Mayor Dave Cull is calling for the government to consider using legislation to protect the "globally significant" Foulden Maar.
The move to further support the Maar's preservation and its fossil record, follows a council decision last month to set aside its original letter of support for commercial exploitation of the site.
The council will also appoint independent commissioners to oversee the ongoing consent process.
Also joining Kathryn is Dr Jennifer Eccles, president of Geoscience Society of New Zealand, with her reaction to Dunedin City Council's move.