Mineral explorer Aurumin has kicked off a barrage of diamond drilling after completing the RC portion of its exploration campaign at the company’s 784,300-ounce Central Sandstone gold project in WA.
Nine holes for 1245m of RC drilling on the project’s 86,500-ounce Shillington deposit have been completed in addition to five RC “pre-collars” at the company’s Two Mile Hill Tonalite deposit.
Explorers will often use RC and diamond methods in conjunction for an effective means of exploration and resource-focused drilling.
Typically, a pre-collar is plunged into the ground using an RC drill bit before swapping over to a diamond drill bit to complete the hole with a “core tail”.
The RC bit is used for the first portion of the hole because it is effective and economical at chewing through the less important rocks covering a deposit or zone of interest.
A diamond drill bit is used for the core tail as it can retrieve informative core samples from the target however it is much more expensive.
In this case the targeted zone is a tonalite rock that formed from cooling magma and extends deep underground. Importantly, the tonalite is associated with the project’s largest hoard of gold.
Aurumin is currently finishing off the core tails into the Two Mile Hill tonalite between 250m and 500m below the surface, aiming to bolster its existing underground resource of 500,000 ounces.
The company expects the diamond portion of the program to take about two weeks, with further logging and sampling to be completed at the end of the program.
Aurumin Managing Director, Brad Valiukas says: “We see the Two Mile Hill underground resource as a key part of the project going forward, with the scale to potentially underpin future production.”
The total resource at the Central Sandstone project is spread out over 11 deposits with the largest on the surface being Shillington and the biggest overall being the underground tonalite component of Two Mile Hill grading about 1.1 grams per tonne gold.
Previous drill efforts into the underground section have delivered an extremely broad calibre of intercepts including 234m at 2.13 g/t gold.
The long lengths of solid gold mineralisation have Aurumin confident they can boost the grade of its underground resource from 1.1 to above 2 g/t gold.
However, the real test will be for Aurumin to amass enough positive assays for a substantial resource upgrade once it completes its program.
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By Matt Birney
