The largest prospecting permit is given by Crown Minerals to Glass Earth, they have begun a $4 million, four-month long, almost 18,000sq km airborne geophysical survey of Otago.

Glass Earth project geologist Sean Doyle said that it is the most significant project on Otago geology ever done and that it will get more than $4 million worth of value out of this project.

There will be used the helicopter-borne Resolve system with a magnetic gradiometer to target the top 100m of the earth's crust for minerals, the area of most interest for Glass Earth.

Glass Earth in mid-October raised $10 million from the fully-subscribed offer. The capital would fund the company's exploration and drilling programmes during the next two years with the regional council contributing about $1 million of the Otago survey's $4 million cost.