The Government has opened up much of the volcanic plateau for gold and silver prospecting, including one of the largest tracts of native forest left in the North Island.
The Ministry of Business, Innovation and Employment's petroleum and minerals department said it was seeking tenders for exploration permits for more than 8000sq km of the Central Volcanic Zone across the Bay of Plenty and Waikato.
The area is known to contain epithermal-style gold and silver deposits in both extinct and active geothermal fields, according to David Binnie, general manager of NZ Petroleum & Minerals.
Although the area tagged for exploration includes conservation land, Mr Binnie said any Schedule 4 areas were excluded. But the Green Party pointed out the area included the Pureora Forest Park, west of Lake Taupo, which does not have Schedule 4 protection.
"The Government should not be tendering for mineral exploration permits in this precious place" Green Party mining spokeswoman Catherine Delahunty said.
"The Pureora forest is some of the best lowland forest remaining in the North Island. The majority of the ancient totara trees remaining in New Zealand are found in Pureora."
But Conservation Minister Nick Smith said the bid process was at a very preliminary stage, "and it is far too early to speculate on whether any mining proposals, either opencast or underground, will eventuate".
"This is about finding out what resources we have and then, as a country, we can make better informed decisions about the tradeoffs between conservation values and jobs from minerals development. Tenderers need to be aware that just because there may be minerals in an area like Pureora Forest does not mean they will get access to them to mine."
Exploration permits are valid for five years but may be extended for up to 10 years. The permit does not give the holder automatic access to explore for minerals.