Diamond drilling by Cooper Metals Ltd (ASX:CPM) has uncovered untested copper-gold potential at King Solomon 1 prospect within the Mt Isa East Project in the resource-rich Mt Isa region of northwest Queensland.
Assay results for all four diamond drill holes have now been received, while a trial downhole electromagnetic survey (DHEM) has been completed.
The four holes, 23MEDH001 to 23MEDH004, were spaced from the northwest to the southeast along the 650-metre-long King Solomon 1 mineralised trend.
The results — with an intercept of 21.4 metres at 2.1% copper and 0.08 g/t gold from 81.6 metres deep, including 5.9 metres at 5.7% copper and 0.08 g/t gold in hole 23MEDH002 — demonstrate the additional potential to extend the known mineralisation at the prospect.
A new interpretation of the diamond core indicates that significant copper-gold mineralisation is controlled by the sheared contact between the brittle Argylla Formation and more ductile Corella Formation.
Drill hole 23MEDH001 in the northern portion of King Solomon 1 intersected a previously unidentified copper-gold zone that appears to be an extension of the well-mineralised quartz-carbonate load formed along the Corella/Argylla contact further to the southwest. This opens up an untested area along strike to the northwest along the edge of the IP anomaly.
A 6.4-metre intercept grading 1.3% copper and 0.13 g/t gold from 175.5 metres deep from this hole (23MEDH001) highlights a newly untested portion of this prospective contact in the northern section of King Solomon 1 and has the potential to significantly extend the mineralisation along strike and down dip.
A new untested zone
Cooper managing director Ian Warland said: “The diamond drilling has shown that the copper-gold mineralisation is strongly controlled by the location of the contact between the brittle Argylla Formation and the more ductile Corella Formation rocks. A consistent brecciated to laminated quartz-carbonate mineralised shear zone has formed adjacent to this contact.
“Prior to the diamond drilling, we had interpreted copper-gold mineralisation to pinch out in the northern portion of King Solomon, however, drill hole 23MEDH001 has intersected the mineralised structure and has uncovered a new untested zone, worthy of further drill testing.”
Could extend mineralised envelope
The trial DHEM survey identified conductive responses in two drill holes with the modelled conductor plate in one extending about 100 metres below the drill hole. This untested area could significantly extend the mineralised envelope at the prospect.
DHEM indicated that the copper-gold mineralisation ranges from nonconductive to weakly conductive and therefore the use of DHEM is limited, however, a conductive response was identified in drill holes 23MEDH002 and 23MEDH004. The latter indicates potential for mineralisation to extend at depth for at least another 100 metres below 23MEDH004.
“The DHEM trial has highlighted a conductive plate extending around 100 metres below drill hole 23MEDH004 in the southern portion of King Solomon 1. All in all, the diamond drilling has shown additional potential to extend the mineralisation at King Solomon 1,” said Warland.
Looking ahead
The recent diamond drilling at King Solomon 1 has helped refine the geological model and highlights the potential to test the northern and southern extensions of the mineralisation adjacent to the Corella/Argylla formation contact.
Cooper continues to plan drilling to best test these new prospective zones.