Rich deposits of copper have been detected by an aerial survey in Northland.
The survey also detected significant amounts of gold, silver, zinc, antimony and lead.
The survey results were analysed by GNS Science, which says there are massive deposits of copper sulphide at Pakotai and Parakao inland from Whangarei and at Pupuke, north of Kerikeri.
These areas have been mined before - Pupuke in the early 1900s, Pakotai from 1944 to 1951 and Parakao in the early 1960s.
The latest report finds copper worth prospecting in these areas along with potentially economic quantities of zinc and gold.
The findings were issued on Wednesday by Resources Minister Phil Heatley.