Auroch is eagerly awaiting assay results from the three-hole diamond drill program at the Nepean nickel project on the back of intriguing observations of the cores.

The first hole NPDD005 intercepted a thick package of ultramafic units from 92m to 253m down-hole that was crosscut in places by intrusive pegmatite veins

Notably, the important footwall contact to the ultramafic package was intercepted at 253m and characterised by a two metre wide sediment unit containing approximately 10% sulphides of predominantly pyrrhotite, pyrite and chalcopyrite.

This unit exhibits a cumulate texture and the presence of sulphidic sediments on the contact is typical of the setting required for Kambalda-style nickel sulphide mineralisation.

Auroch Minerals (ASX:AOU) has also completed a down-hole electromagnetic (DHEM) survey on the hole that confirmed that the intercepted sulphides are probably the cause of the moving-loop electromagnetic (MLEM) conductor that was the target of the drill program.

“The core provided by diamond drilling allows our geologists to record so much more textural and structural information that is just not possible to see in RC drill chips, and hence is critical to understanding the geological setting of each prospect,” managing director Aidan Platel said.

“The sulphidic sediments intersected by drill-hole NPDD005, whilst not nickel sulphides, are important as they provide the source of sulphur necessary for Kambalda-style nickel sulphide mineralisation, and the fact that they are underlying a thick ultramafic package is very encouraging.

“The DHEM survey has provided us with an orientation of the dip and plunge of the all-important footwall contact, and we eagerly await the geochemical assays from this core to assess the fertility of the basal ultramafic unit and to get a possible vector on where the footwall channel and potential nickel sulphide mineralisation may lie.”

He added that the company is looking forward to potentially identifying new conductors for its next drilling campaign once it resumes its MLEM

Other drill holes

The second hole NPDD006 targeted a geochemical anomaly about 1.8m north of the historical Nepean mine that was identified in the company’s aircore drilling earlier this year that intercepted 1m at 0.6 per cent nickel.

NPDD006 was drilled to a depth of 255m and intersected the ultramafic – basalt footwall contact at 180m down-hole.

Meanwhile, the third hole NPDD007 was drilled as a metallurgical hole to better understand the shallow high-grade nickel sulphide mineralisation intersected in recent reverse circulation drilling.

It intersected a 10m sulphide zone from 66m that included a 3.4m ‘triangular ore zone’ mineralisation from 72.4m down-hole.

This ‘triangular ore zone’ is a mineralised unit noted in historic orebody descriptions at the Nepean nickel mine and is characterised by 10-40% matrix sulphides consisting of pentlandite and pyrrhotite which take on a triangular appearance.

DHEM will be carried out on both holes later this week.




This article was developed in collaboration with Auroch Minerals, a Stockhead advertiser at the time of publishing.


This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.