Australian-listed gold explorer New Age Exploration (NAE) has relinquished 75% of two permits areas in Central and South Otago, after initial exploration results proved largely inconclusive.
The overall exploration programme is modest by industry standards, but NAE will continue scaled-back studies heading into next summer.
The Mahinerangi permit, northeast of Lawrence, will be reduced from 418sqkm to 154sqm, while the Teviot permit, just east of Roxburgh, was reduced from 458sqkm to 66sqkm.
NAE received approval for two two-year, low-impact gold-prospecting permits last year but with a lack of conclusive results so far, it has scaled back the size of its holding, which will also save it some permit costs.
However, NAE has not given up and more sampling and scrutiny of the permitted areas are scheduled to resume after winter.
The southeastern boundary of the Mahinerangi permit is just 9km from the historic Gabriels Gully goldfield, which yielded more than 500,000oz from 1861.
NAE said it believed recent research had identified a "mirror image" in the south of the Otago schist belt of similar geology to that in the north of the belt and about 60km from Oceana Gold’s Macraes mine; where about 5million oz of gold have been extracted in the past 27 years.
NAE managing director Gary Fietz said the southern areas of the respective permits were identified "as the most prospective" to hold any gold and NAE would work on a "small follow-up programme" after winter.
"We have made a decision to reduce our South Otago permit areas down to 25% of the previous areas due to the lack of any conclusive results to date," he said in an ASX statement.
Exploration had so far come under the budgeted $150,000, $26,000 having been spent on the permit and $84,000 on exploration. NAE and technical consultants CRL Energy and Dr Doug MacKenzie, from the University of Otago, were working on an exploration strategy to further explore the remaining areas.
The low-impact sampling had included 877 soil samples of up to 400g each being taken by hand auger to depths of up to 2m, and the collection and analysis of 246 rock-chip samples.
NAE said the soil and rock-chip samples were "inconclusive" in that they had not identified any pathfinder minerals, such as arsenic, to prompt follow-up exploration.
A "man-portable" drill was used to drill 21 holes, to a depth of 6m, most of which penetrated the thick layer of loess, a silty sedimentary deposit.
Dr MacKenzie and his colleague Prof Dave Craw, also from Otago University, believe the southeastern side of the schist belt on the two permitted areas could have similar gold mineralisation as the Macraes end of the schist belt.
NAE said new mapping by Dr MacKenzie on both permits had provided better resolution of the regional structure of the metamorphic basement rocks, but had not identified any significant shear zones for potential gold mineralisation.
