Rio Tinto Exploration has withdrawn from a farm-in agreement with Tasman Resources over Vulcan iron oxide copper-gold-uranium project in South Australia.
The farm-in between both the firms started in 2012 and provided Tasman with $10m cash to advance the Vulcan project.
The deal also allowed Tasman to identify new high-priority targets for follow-up.
Tasman Resources said that following the completion of the initial exploration programme, Rio Tinto Exploration elected not to proceed with earning the stage one participating share under its farm-in/joint venture agreement.
Tasman will continue as the sole owner of 100% of the Vulcan project, which is part of the company's Lake Torrens project.
With Rio Tinto Exploration's withdrawal from the farm-in, Tasman said it intends to advance exploration at Vulcan either through a new joint venture agreement or on a sole-funded basis.
The company will decide which option to adopt over the coming months.
In late 2009, Tasman drilled the first hole at the Vulcan prospect, which is located about 30km north of Olympic Dam.
Drilling to date has intersected several thick intervals of alteration and low-grade mineralisation over a large target area about 12km².
Tasman said on a more regional basis, an area of about 90km² immediately to the west of Vulcan is also believed to be attractive, but it is considered a grass roots exploration target.
The company has also identified specific priority drilling locations at the Zeus prospect and at Marathon East, which is located south-east of Vulcan.
Image: Bouguer gravity image with residual gravity insert showing Titan and Zeus Prospects. Photo: courtesy of Tasman Resources.