Resources & Energy Group Limited (ASX: REZ) has received promising results from a petrological and lithogeochemical study at the Springfield Prospect within its East Menzies Project in Western Australia.
The study was carried out on three drill holes (SFRC01, SFRC04 and SFRC05) selected from a suite of nine Reverse Circulation (RC) drill holes completed at the Springfield Prospect during 2021.
On the basis of mineralogy, geochemistry, and textural attributes, seven of the samples in two of the holes examined contained recrystallised Ni‐Fe sulphides of primary magmatic origin.
The confirmation of magmatic Ni‐Fe sulphide mineralisation is a significant and material exploration result for the Springfield Project and the East Menzies Package in general. It allows for the possibility that the ultramafics and nearby lithologies may host larger accumulations of disseminated and massive Ni‐Fe sulphides.
The Springfield area was identified by the company following a review of historical exploration and gold mining activities. The documented occurrences of sulphides north of Springfield at Cepline, were also considered to be prospective features for the occurrence of magmatic nickel sulphides, volcanic exhalative nickel sulphides and base metals deposits.
The company has targeted these occurrences rather than the shallow near‐surface lateritic nickel deposits, which have been subject of previous investigation at East Menzies and elsewhere in the broader Menzies region.
The petrological studies were carried out on selected RC chip samples to follow up previously reported nickel, cobalt, chromium, zinc, copper, and molybdenum results obtained from the initial Springfield scout drilling programme.
This work included the following peak down the hole assays:
· SFRC01‐1m @1.78% Ni, 0.21% Cr, 5% S, 269ppm Mo and 245ppm Cu from 98m.
· SFRC04‐1m @ 0.5 % Ni, 0.19% Cr, 4.4% S, from 88m
· SFRC05‐2m @ 1.02% Ni, 0.6% Cr, 0.4% Zn, from 29m and 2m @ 1.1 % Ni, 1% Cr, 0.49% S, 0.45% Zn, 0.07% Co from 36m, included within 9m @ 0.8 % Ni, 0.62% Cr, 0.31% Zn from 29m
At the time these results were reported by the company, the form or mode of occurrence in which these metals were present was not known and required petrological assessment to understand the significance of the mineralised intervals.
In this connection, the company engaged a leading industry expert‐ Ben Grguric to evaluate the samples and provide an overall assessment of the prospectivity of the results, with focus on magmatic nickel mineralisation.
Some key observations from the petrographic work completed by Dr Grguric were the identification of Ni‐Fe sulphides namely pentlandite, violarite, smythite and gersdorffite.
These minerals were present either in the form of discrete grains and blebs and in one sample, SFRC01 98‐99 m (assaying 1.78% Ni), in net‐textures associated with pyrrhotite. These sulphides were hosted in komatiites, metapyroxenite and strongly‐silicified komatiites (birbirites).
The three RC drill holes examined in the study represent points of observation over a strike length of approximately 600 m and allow for hypothesis that the same ultramafic units elsewhere in the Menzies package could be host to larger accumulations of magmatic Ni sulphides.
There has been a general although not unanimous view that the Ni‐Fe sulphide potential of the Menzies area had been exhausted by previous exploration.
However, these earlier investigations have been primarily focussed on lateritic resources. In a regional context, there are two notable exceptions where magmatic sulphides have been reported from interpreted strike extensions of the Menzies package by Ardea Resources at Ghost Rocks to the north, and the Highway Project to the south.
The confirmation of Ni‐Fe sulphides at Springfield at shallow depths along a significant strike interval is an important and material exploration result. This observation provides a great boost to the prospectivity of the Springfield Project and the East Menzies package overall.
Next Steps
The company is awaiting receipt of multi‐element and gold/platinum group element assays from the December 2021 drilling programme. These results are expected in the next few weeks. The outcome from this work will enable the company to develop a suitable exploration program over this part of the project area
