De Grey Mining Limited (ASX:DEG) has intersected very encouraging sulphide-rich alteration over large widths and depths from initial reverse circulation (RC) holes drilled on Section B at the newly discovered Hemi Prospect within the Mallina Gold Project in WA.
The sulphide zone at Section B expanded to over 160 metres wide and greater than 120 metres depth in RC drilling immediately below the known shallow gold mineralisation, including:
- 97 metres of sulphide mineralisation (downhole) in HERC001; and
- 45 metres of sulphide mineralisation (downhole) in HERC002.
- New additional parallel sulphide zones increase scale potential with new zones of 19 metres and 15 metres (downhole) in HERC002 and HEDD001 pre-collar.
Section B showing new RC drill holes with extensive sulphide alteration below the gold zone
In Section A, drilling intersected fresh and intense sulphide mineralisation from 192 metres (downhole) to 204 metres where the drilling rods have become bogged and drilling had to cease.
De Grey technical director Andy Beckwith said: “The significant sulphide zones beneath the high-grade gold zones on Sections A and B are very encouraging.
“The large sulphide zones on Section B have the potential to significantly increase Hemi’s scale.
“The genetic link between Sections A and B as intrusion hosted is exciting and increases the potential at Hemi.
“This is supported by the aircore drilling results to date that highlight every hole above the interpreted intrusions are anomalous in gold.
“The aircore and RC programs are continuing, and a diamond rig is expected on site later this week.”
Mallina Gold Project showing main gold deposits and the new Hemi Discovery
At Section B, the alteration assemblage comprises quartz-sericite-sulphides (pyrite and arsenopyrite) with the sulphides hosted in fine sheeted veins and ranging from about 5% to 10% of the rock mass.
The fine-grained nature of the sulphide mineralisation makes accurate percentage estimates difficult and full assays results and detailed diamond core are expected to provide further definition of alteration and sulphide percentages.
Further drilling is currently planned to include an initial diamond core extension to precollar HEDD001 and two planned RC holes to the south prior to step out drilling along strike.
All assay results remain pending.
Aircore drilling - Section D
Further encouraging gold results have been received from the original 320 metres x 160 metres spaced aircore drilling program completed prior to Cyclone Damien.
Significant results include 45 metres at 0.4g/t gold from 36 metres including 12 metres at 0.9g/t gold in BWAC357 on Section D.
Additional aircore drilling has recommenced targeting strike extensions of the known mineralisation on 160 metres x 40-80 metres spaced holes.
Encouraging alteration is evident in a number of new step out aircore holes with further information to be provided once assay results are finalised.