Wirlong is located within Exploration Licence 8307, approximately 20km west of Nymagee and 70km south-southeast of Cobar. The large prospect comprises a package of intercalated, sheared and altered felsic volcanics and sediments. It is defined by historic copper workings, a topographic high, a >2km surface multi-element geochemical anomaly, and coincident or semi-coincident geophysical anomalies including magnetic, radiometric, gravity, IP and electromagnetic.
Work to date
Early stage exploration drill results testing the geochemical and geophysical anomalies at Wirlong returned strong base metals mineralisation, including 4m @ 3.04% Cu, 12 g/t Ag, 0.19% Zn from 196m in WLRC005, 2m @ 2.99% Cu, 1.08 g/t Au, 16 g/t Ag, 0.41% Zn from 322m in WLRC006, and 2m @ 2.30% Zn, 0.81% Pb, 4 g/t Ag from 139m in WLRC007.
Two RC holes completed to test beneath the historic workings also intercepted broad zones of highly anomalous copper-lead-zinc-silver mineralisation from close to surface, with best intervals including 5m @ 1.64% Zn, 0.82% Pb, 2 g/t Ag from 93m and 1m @ 6.44% Zn, 3.81% Pb, 0.54% Cu, 18 g/t Ag from 113m in WLRC008, and 19m @ 2.44% Zn, 0.39% Pb, 4 g/t Ag from 103m (incl. 3m @ 6.90% Zn, 0.88% Pb, 12 g/t Ag from 120m) in WLRC009.
Subsequent drilling programs have since confirmed a new high-grade copper discovery at Wirlong, with results indicating that the prospect represents a very large, mineralised, hydrothermal system with a strike length of more than 2.5km. Hole WLRCDD015, drilled to target the northern end of Wirlong’s extensive multi-element geochemical anomaly along with gravity, IP chargeability and magnetic anomalies, returned better intercepts of:
- 4.9m @ 4.3% Cu, 13 g/t Ag from 402.1m (incl. 0.9m @ 19.5% Cu, 58 g/t Ag from 402.1m)
- 22m @ 1.0% Cu, 4 g/t Ag from 332m
- 3m @ 2.1% Cu, 6 g/t Ag from 451m
- 2m @ 1.8% Cu, 1.63% Zn, 13 g/t Ag from 524m
Follow-up diamond hole WLDD001 also returned:
- 9m @ 8.0% Cu, 17 g/t Ag, 0.21 g/t Au from 616m (incl. 2.82m @ 21.85% Cu, 46 g/t Ag, 0.62 g/t Au from 619.68m)
- 38m @ 1.18% Cu, 4 g/t Ag from 450m
- 6m @ 1.23% Cu, 5 g/t Ag from 430m
- 4m @ 1.14% Cu, 3 g/t Ag from 643m
Ensuing drillholes completed up-dip of and north along strike from WLRCDD015 encountered multiple intercepts of copper and zinc mineralisation, accompanied by extensive sericite and chlorite alteration. Better intervals are summarised below, with the true width of mineralisation inferred to be between 40-50% of the down-hole widths:
- 121m @ 0.73% Cu, 3 g/t Ag from 207m (incl. 26m @ 1.21% Cu, 5 g/t Ag from 227m, 5m @ 1.14% Cu, 3 g/t Ag from 260m, 2m @ 1.24% Cu, 5 g/t Ag from 278m, 10m @ 1.01% Cu, 4 g/t Ag from 288m), 1m @ 4.81% Cu, 10 g/t Ag from 556m, 2m @ 2.23% Cu from 617m, and 0.4m @ 3.01% Zn from 858m to EOH in WLRCDD024
- 2m @ 3.80% Cu, 10.5 g/t Ag from 36m and 9m @ 1.27% Cu from 255m in WLRC026
- 2m @ 1.14% Cu from 62m and 2m @ 2.06% Cu, 20 g/t Ag from 106m WLRCDD027
- 90m @ 0.68% Cu, 3 g/t Ag from 412m (incl. 9m @ 1.29% Cu, 7 g/t Ag from 412m and 19m @ 1.36% Cu, 6 g/t Ag from 432m), 1m @ 0.57% Pb, 6.96% Zn from 546m, and 1m @ 0.95% Zn from 592m in WLRCDD028
The last completed drilling program at Wirlong, designed to test for potential oxide/supergene copper mineralisation, also returned several new significant near surface intercepts and a number of holes have shown indications of continued mineralisation past the end-of-hole; follow-up extensional drilling is now underway.
- 1m @ 1.77% Zn from 72m, 10m @ 0.64% Zn, 0.26% Cu from 91m, 7m @ 0.53% Cu, 0.34% Zn from 111m and 3m @ 0.94% Zn, 0.24% Pb from 119m in WLRC029
- 9m @ 0.47% Cu from 35m in WLRC030
- 6m @ 0.77% Cu from 106m (incl. 2m @ 1.34% Cu from 108m) and 6m @ 0.52% Cu from 127m in WLRC032
- 2m @ 1.28% Cu, 0.54% Zn from 67m and 3m @ 1.88% Cu, 7.6 g/t Ag from 103m in WLRC033
- 9m @ 0.83% Zn, 0.30% Pb from 75m (incl. 3m @ 1.15% Zn, 0.50% Pb, 7.2 g/t Ag from 78m) and 2m @ 2.00% Cu from 117m in WLRC034
- 1m @ 2.15% Cu, 0.60% Zn, 13.6 g/t Ag from 63m and 9m @ 3.29% Cu, 0.60% Zn, 18 g/t Ag from 70m in WLRC035
- 1m @ 1.13% Cu from 65m and 1m @ 1.24% Cu from 76m in WLRC036
The Red Shaft prospect is located approx. 4km SSE of Wirlong. The prospective stratigraphy that hosts the mineralisation at Wirlong is traceable to the Red Shaft prospect, indicating a mineralised trend covering more than 6km strike. Rock chipping at Red Shaft has returned significant Cu, Ag and As values, as well as gold values of >2 g/t (up to 4.99 g/t Au) returned over a 70m zone. Highly elevated gold and base metal values have also continued to be seen in follow-up RAB and RC drilling, with better intercepts including:
- 19m @ 0.20% Pb from 1m in RSRAB032, including 3m @ 0.20% Pb from 1m, 2m @ 0.39% Pb from 6m and 1m @ 0.38% Pb from 11m
- 29m @ 0.37% Pb, 0.11% Cu from 1m in RSRAB035, including 3m @ 0.68% Pb, 0.11% Cu from 2m, 3m @ 0.59% Pb, 0.12% Cu from 10m, 2m @ 0.72% Pb, 0.15% Cu from 14m and 3m @ 0.55% Pb, 0.18% Cu from 18m
- 2m @ 0.54% Pb from 8m in RSRAB037
- 15m @ 0.86 g/t Au from 7m in RSRAB035
- 1m @ 1.21% Pb from 31m and 6m @ 0.44 g/t Au from 48m in RSRAB043
- 1m @ 1.53% Pb from 34m in RSRAB045
- 10m @ 0.84 g/t Au, 0.20% Cu, 0.26% Pb from 60m including 4m @ 1.88 g/t Au, 0.35% Pb from 61m in RSRC003
- 5m @ 0.76% Cu from 62m in RSRC007
- 4m @ 0.48% Pb from 41m in RSRC009
- 2m @ 0.80% Pb from 61m in RSRC011
The Sandy Creek prospect is directly along strike from the stratigraphic contact intersected at the Mallee Bull deposit and occupies the same geological unit; a north-south trending belt of sandstone and siltstone of the Shume Formation, a proximal turbidite sequence separating the sedimentary packages of the Upper and Lower Amphitheatre Groups.
North-South trending massive bucky quartz veins and quartz stock work veining in the area are evidence of a high strain and structurally complicated environment. Furthermore, there are interbedded siltstone, sandstone and volcaniclastic units; all features identified at Mallee Bull and thought to facilitate a heterogeneous strain regime suitable for creating dilational sites for mineral deposition.
A coincident IP anomaly and discrete magnetic low identified in the area was the target for historic diamond hole SCDD001 drilled in 2002 by Pasminco. Down-hole EM identified a very strong off-hole conductor (>1000 siemens) 50m below and slightly north of SCDD001. This conductor was the target of hole SCDD002 drilled in 2003 which returned 10.2m @ 1.6% Cu, 7.4% Pb, 68 g/t Ag from 521.8m. In August 2013, follow-up drilling by Peel was completed with diamond hole PSCDD001. Several broad zones of mineralisation/alteration were intersected including; a 25m zone of disseminated pyrrhotite-dominant sulphides from 237m; and a 19m zone of variable pyrrhotite-dominant sulphides from 493m including a 4m zone of strong galena-dominant mineralisation averaging 48 g/t Ag, 0.50% Cu, 9.63% Pb, 1.1% Zn from 493m. The true width of these intercepts is estimated to be close to the down-hole intercept. Follow-up high-powered DHEM survey of PSCDD001 indicates that the anomaly remains open in multiple directions.
Subsequent activities at the Sandy Creek prospect have included a detailed gravity survey, diamond, RC and RAB drilling, with encouraging mineralisation encountered in diamond drillholes PSCRCDD002 and PSCDD002. In PSCDD002, drilled to target a strong chargeable IP and DHEM anomaly situated about 500m below surface in the central part of the main prospect, several intervals of locally strong pyrrhotite-pyrite-sphalerite-chalcopyrite-galena mineralisation were found to occur in narrow massive veins and fracture fills with associated sericite and chlorite alteration. Significant intercepts include 1m @ 82.3 g/t Ag, 1.48% Cu, 9.16% Pb, 5.36% Zn from 499m and 1m @ 25.4 g/t Ag, 3.65% Pb, 6.91% Zn from 502m; the results continue to highlight the potential of Sandy Creek to host economic mineralisation.