Auroch Minerals Ltd's (ASX:AOU) (FRA:T59) three-hole diamond drilling program at the Nepean Nickel Project joint venture targeting three separate targets including MLEM conductor, geochemical anomaly and shallow near-mine mineralisation, has provided encouraging observations.
While assays are pending, drill hole NPDD005 targeting a 4,000-8,000S MLEM conductor intersected a fertile ultramafic unit on sediment contact at a depth of 253 metres.
Down-hole Electromagnetics (DHEM) conducted on the completed hole confirmed that the intercepted sulphides are probably the cause of the MLEM conductor.
A refined DHEM model has produced a 4,500-6,000S conductive plate with dimensions of 100x150 metres. It is steeply dipping WNW and striking NNW-SSE, which is coincident with the lithological strike.
The core is being processed and sampled and submitted for assaying, with results, in particular the geochemistry of the contact zone, to be used for further drill targeting.
The Nepean Nickel Project is a joint venture with Auroch holding 80% and Lodestar Resources Ltd 20%.
Benefits of diamond core
Managing director Aidan Platel said: “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.
“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.
“Our Nepean MLEM survey resumes this week, so we are looking forward to potentially identifying new conductors to target the next drilling campaign at Nepean."
Other diamond holes
The second diamond drill-hole (NPDD006) targeted a geochemical anomaly identified in Auroch’s aircore drilling earlier this year, in which hole NPAC004 intercepted 1-metre at 0.60% nickel from 67 metres in an end of hole sample in fresh rock.
This anomaly is around 1.8 kilometres north of the historic Nepean mine.
Hole NPDD006 was drilled to a depth of 255 metres and the ultramafic-basalt footwall contact was intersected at 180 metres down-hole.
A DHEM survey of this hole has been scheduled for later this week.
The third diamond hole (NPDD007) was drilled as a metallurgical hole in order to better understand the shallow high-grade nickel sulphide mineralisation intersected in recent reverse circulation (RC) drilling.
Drill core from NPDD007 will be processed and assayed and half of the HQ diameter core will be retained for ongoing metallurgical work.
DHEM on the hole is scheduled for later this week, with the aim of understanding the conductive response of the matrix sulphide unit. This will aid in the future targeting of regional exploration drill programs.
Ongoing exploration
The high-powered ground MLEM resumes this week at Nepean after several delays due to equipment issues.
This survey will cover critical areas of the Nepean strike both to the north and south of the historic mine and is due to be completed within the next two weeks.
Drilling continues at the Leinster Nickel Project at the Woodwind prospect, directly along strike from the known high-grade nickel sulphide mineralisation at the Horn Prospect.
To date, five diamond holes for 1,660 metres and seven RC holes for 1,300 metres have been completed.
Assays are pending for all holes, with the first batch of results expected in the coming weeks.
DHEM has been scheduled for next week for all completed drill holes.
Platel added: “We are also awaiting assays for 12 drill holes from the Woodwind Prospect, along strike from the high-grade nickel sulphide mineralisation at Horn Prospect at the Leinster Nickel Project, and we expect to have the first batch of results from these holes within the next two weeks, so exciting times ahead for the company.”