Perhaps best known for its Halls Creek copper project joint venture with Cazaly Resources in Western Australia’s Kimberley region, 3D aims to acquire Croydon for $A10,000 cash and 40 million of its shares (about 14.2% of 3D) to be issued over four milestone-linked tranches.

Croydon’s sole asset is its 100% stake of EP40752, which surrounds the mining permit for the historic state-owned Tatu underground mine in the North Island’s Tangarakau coalfield that produced more than 1 million tonnes of thermal coal from 1940-1971.

The exploration permit was acquired in a conditional deal struck with cash-strapped Solid in April, with regulatory approval for a two-year extension expected in 1-2 months.

Based on the limited exploration to date, 3D suspects the 74sq.km licence hosts at least 20 million gross in-situ tonnes to provide a 10 year-plus mine life.

The licence also has logistical advantages with the Tatu mine close to existing rail and spare capacity available at the Port of New Plymouth, which was part of Pike River Coal’s export plans before its 2010 mine disaster and subsequent liquidation.

3D’s deal is subject to standard regulatory approvals and the successful completion of due diligence by December 17.

3D director and former chairman Ian Richer resigned on Monday ahead of the deal announcement.