Great Boulder Resources Ltd. said March 13 that it finalized an option to earn up to a 75% stake in Ausgold Ltd.'s Winchester nickel-copper project in Western Australia.

The ASX-listed explorer can earn up to 75% of the early-stage project by issuing 1.5 million shares and spending A$500,000 on exploration in three phases over four years. Great Boulder has already spent about A$100,000 at the operation.

Once Great Boulder meets the minimum expenditure, Ausgold will retain a 25% free-carried interest in the operation until a decision to mine is reached.

Exploration activities are underway at Winchester. A 3,400-meter aircore geochemistry drilling program started this week, and a gravity survey will start in the coming weeks.

Meanwhile, Great Boulder applied for a tenement immediately south of the project's granted tenement, E38/2129, which hosts a strike extension.