Estrella Resources Limited (ASX: ESR) has revealed that both new parent diamond drill holes collared last week at the T5 Prospect, located within the Carr Boyd nickel-copper project approximately 80 north of Kalgoorlie, have intersected massive to globular sulphides on the basal contact.
Hole CBDD055 targeted an area towards the middle of the T5 Conductor and up-dip from hole CBDD054. The CBDD055 intersection of 13.75m of massive to globular sulphides lies at the base of a much broader sulphide intersection totalling some 44.7m downhole.
The upper area of predominantly disseminated sulphides (355.3m – 383.8m) represents a mineralised halo above the basal sulphide zone where finer-grained sulphides are being mobilised through the T5 Feeder.
The massive and globular sulphides in the lower part of the intersection show evidence of sulphide settling from a silicious plume that is believed to carry the majority of sulphides through the feeder to the T5 trap site.
Our success at hitting significant zones of nickel-copper-iron sulphides continue at Carr Boyd and its extremely pleasing to see that our exploration efforts are being rewarded at the drill-bit,” Managing Director, Chris Daws, said.
“The understanding of Carr Boyd has greatly improved since our deep drilling program kicked off late last year and I am confident we will continue to locate metal sulphides within this very prospective system.
“The company is in the strongest position ever since acquiring Carr Boyd after the successful A$11.3M underwriting of the Company’s June options and exercise by its shareholders whom I thank for their support in this exciting project.
“I look forward in what our exploration team delivers next as the high impact drilling continues 24/7.”
CBDD050 Intersection Details
CBDD050 targeted an area some 30m south of CBDD055. The hole intersected 6.4m of mineralisation including two heavily sulphidic zones separated by a small mafic dyke and disseminated pyroxenite.
The globular textures are evidence of flow-stripping, where the upper zones of a basal massive sulphide is being eroded by the pyroxenite melt to form a globular to disseminated upper-halo. These sulphides are being carried towards the CBDD055 intersection area and contribute to the upper, fine grained sulphide halo as well as the globular sulphides atop of the silica plume.
The sulphides are extremely dense when compared to the magma within the flow and will not stay suspended for long once any turbidity subsides. As such the down-plunge (down-flow) location is an excellent massive sulphide exploration target. The precise location of “downstream” sulphide settling is currently being vigorously pursued with targeted drilling of the T5 pyroxenite basal contact.
Next Steps
The sulphide textures observed in the current drilling confirm the settling, remobilisation and re-settling of massive sulphides along the T5 Pyroxenite Feeder basal contact. The current aspect of Phase 3 drilling leads the Company to believe that the entire T5 Pyroxenite surface is in the correct orientation to be a sulphide trap with respect to the flow direction and resulting flow dynamics.
The geological model of sulphide deposition the Company is applying at Carr Boyd has been recognised in other significant world class deposits around the globe. The formation of massive sulphides on basal contacts tend not to be isolated occurrences in these very large mineralised systems and the Company continues to be excited by the level of prospectivity being demonstrated at Carr Boyd.
Phase 3 will continue to step-out along the T5 Conductor to gain important vectoring information to further areas of suggested massive sulphide deposition beyond the current T5 Electromagnetic Conductor.