De Grey Mining Limited (ASX:DEG) has received one of the best intersections to date from its Pilbara Gold Project in WA which indicates strong potential to add to the 1.4 million ounce gold resource.
The 56-metre intersection at 3.04 g/t gold from 14 metres at the Mallina deposit included 30 metres at 5.29 g/t.
Recent drilling has also returned high-grade results from the Toweranna deposit’s Western and Southern zones.
De Grey exploration manager Phil Tornatora said Mallina had provided one of the best intersections seen across the project area.
“A wide zone of intense alteration and sulphide development with 56 metres of mineralisation demonstrates the large scale of this system,” he said.
“The recent resource upgrade at Mallina is all above 100 metres, so there is plenty of opportunity for ongoing resource increases as we continue step-out drilling.
“Toweranna continues to show more of the same – high-grade vertically stacked sheeted veins that we expect to continue through the northern and eastern granite contacts and at depth, which our next program will test.”
Only about 10% of the shear zones across the 200-kilometre-plus strike length throughout the large 1,480 square kilometre landholding has been tested.
The Pilbara Gold Project with Mallina and Toweranna highlighted.
Detailed shallow reverse circulation (RC) and diamond drilling to a nominal depth of 100 to 150 metres have resulted in the definition of a 1.4 million ounce resource.
As well as returning the 56-metre intersection, drilling at Mallina also showed ongoing mineralisation at 90-metre depth with further potential to add to the 160,700-ounce resource.
Three holes completed at Mallina
Three diamond drill holes were recently completed to provide additional geological and structural information, in addition to drill core for metallurgical test work.
Test work on the two holes drilled for metallurgical purposes is underway as part of the open pit pre-feasibility study while results have been finalised for the other hole.
This was a diamond tail to a previous RC hole which ended in significant mineralisation.
Mineralisation continues in diamond tail
The mineralised zone continued in the diamond tail, which returned the 56-metre result.
This hole intersected a felsic porphyry around 20 metres below the 56-metre mineralised zone which also shows mineralisation at the hanging wall and footwall contacts, including 8.25 metres at 1.05 g/t.
Mallina Central section results.
Follow-up drilling to test this significant zone of mineralisation will be carried out shortly.
A Sub-Audio Magnetic (SAM) ground geophysical survey is also planned, subject to review of a recently completed SAM survey at the Mt Berghaus deposit.
High-grade results at Toweranna
At Toweranna, nine diamond tails were drilled to extend selected RC holes targeting the Western and Southern zones.
Results have confirmed mineralisation along these zones and provided important structural information used to updated and refine the geological model, in addition to intersecting significant mineralisation.
Best Western Zone results are:
At Southern Zone, best results are:
A drilling plan for Toweranna showing new drill intersections.
The high-grade gold tenor of the individual veins and increased overall resource ounces are expected to boost the shallow open pit mining potential of the deposit, which hosts 143,900 ounces.
Follow-up drilling programs are being planned targeting extensions to the resource on the Eastern and Northern granite contacts, in addition to depth extensions.
De Grey is ramping up exploration throughout the Pilbara project in a drive to upgrade and expand known resources, as well as discover new deposits.
There are more than 40 identified yet untested soil anomalies along the highly prospective regional scale shear zones and conglomerates.