Trial mining of up to 1.6 million tonnes of ore will now begin, with Nimble to fund all set up, mining, processing and rehabilitation costs under the tribute agreement.
If the trial is successful Impact will move to develop a larger open pit mine at Blackridge.
Recent bulk sampling done by Nimble at Blackridge showed wet gravity processing on the large volumes of free-digging oxide ore had a recovery rate of more than 95%.
These results were so encouraging, Impact claims, that Nimble asked for trial mining to begin straight away.
Impact Minerals managing director Dr Mike Jones said the best way to determine grade in coarse gold deposits like Blackridge is to simply start mining.
"This is inherently very high risk and so this agreement gives Impact a very low risk entry to mining by trial mining of only a modest part of the mineralised area which extends over at least 1,500 metres along trend," he said.
"In addition Impact, under the royalty payment provisions will receive at least a modest cash flow from the trial."
Jones said Nimble is a very capable operator and Impact looks forward to working with them and starting the trial as quickly as practicable.