West Wyalong Maiden Drilling Confirms Mineralised Porphyry System
- Multiple porphyritic intrusives intersected over a strike length of 2.5 kilometres.
- Drilling results analogous to the initial exploration results which led to the discovery of Ok Tedi (PNG) and Big Cadia.
- Elevated copper, gold and molybdenum mineralisation evident as signature features of mineralised porphyry systems.
- Widespread strong alteration observed common to porphyry copper-gold-molybdenum deposits with frequent quartz, quartzcarbonate and anhydrite veining.
- Extensive zones of pyrite-dominated sulphides intersected in all drillholes including disseminated and banded pyrite and chalcopyrite, and stringer molybdenite.
- All six holes completed and logged in detail, with assays pending for four holes.
Multiple porphyritic intrusives have been intersected over a strike length of 2.5 kilometres, which are associated with elevated chalcopyrite, molybdenite and gold mineralisation, and extensive zones of sulphide mineralisation - together being signature features of porphyry copper-gold-molybdenum mineralised systems.
The intensity of copper-gold-molybdenum anomalism increases from the northernmost hole AWT001 to the south towards AWT002.
Assays for holes AWT003 to AWT006 which extend further to the south from AWT002 are pending.
Figure 1 (see the link below) is a plan view illustrating the locations of the holes and the geophysical anomalies that the drilling programme was designed to test.
Visual observations of the alteration and mineral assemblages in the drill core, along with voluminous brecciated magnetite skarn and concentrated vein molybdenite and chalcopyrite, indicate that the drilling is near to either a main mineralised body or a series of mineralised bodies.
Within all holes now drilled and logged in detail, widespread alteration ranges from hypabyssal calc-silicate (potassic/propylitic) alteration and magnetite skarn seen dominantly at Theia, to phyllic and argillic alteration typical of epithermal environments seen dominantly at Narragudgil.
Extensive diffuse banded and disseminated pyrite has been observed in the overlying mafic volcanic package, along with disseminated pyrite throughout certain porphyritic intrusives. Most of the drill core has been included for sampling and assay to adequately test for gold and minor copper mineralisation, which is typically not visible in drill core from porphyry systems.
Assays for the first two holes - AWT001 and AWT002
The first two holes drilled (AWT001 and AWT002) were designed to test the northern extent of the Theia anomaly.
The assay results for these two holes, together with the drill core visual observations, are consistent with a near position to a porphyry copper-gold-molybdenum deposit.
The assay results include the following significant intersections by AWT002:
- 24.1 m at 0.25% Cu, 0.11g/t Au and 214 ppm Mo from 161.4 m
including 10.6 m at 0.37% Cu, 0.14 g/t Au and 376 ppm Mo from 161.4 m;
- 17.1 m at 0.08% Cu, 0.02 g/t Au and 559 ppm Mo from 197.3 m
including 0.8 m @ 3,520 ppm (0.35%) Mo from 211.6 m;
and the following significant intersections by AWT001:
- 4.0 m at 0.04% Cu, 0.01 g/t Au and 174 ppm Mo from 143.5 m
- 4.0 m at 0.23% Cu, 0.03 g/t Au and 31 ppm Mo from 223.6 m
- 7.8 m at 0.40 % Cu, 0.01 g/t Au and 9ppm Mo from 313.5 m
including 0.6 m @ 1.59% Cu from 319.7 m.
Each of the above intervals are contained within broader anomalous copper (>0.01%) zones that surround narrow dykes and sills of tonalite to monzonite composition that are indicative of a complex, poly-phase, fertile system. The dykes and sills intrude through host volcanogenic units to the east and a monzonite intrusive stock to the west (drill core petrology pending).
Identified peers are the magnetite skarns at Ok Tedi in Papua New Guinea (PNG) and at Big Cadia. The geochemistry and lithology at Big Cadia provided important clues that ultimately led to the discovery of the considerably larger Cadia Ridgeway deposit.
For additional information on porphyry copper-gold system exploration, investors may wish to read the article about the discovery process at Cadia by John Holliday, Colin McMillan and Ian Tedder:
All drillholes have been logged and sampled. Assays for the remaining four drillholes are pending.
Upon finalisation of assays and QAQC processes, 3D modelling will be undertaken to fully understand the geometry of the area and the implications of the assays.
Further to this, hyperspectral logging (Short Wave Infrared) of all drill core will be undertaken to fully appreciate the extent and composition of alteration to aid in further drill planning, and petrographic analyses will be undertaken to specifically quantify the present rock types, and implications of those rock types.
Detailed information about the results from AWT001 and AWT002 is reported in the following appendices (see the link below).
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About Argent Minerals Limited
Argent Minerals Limited (ASX:ARD) is an Australian publicly listed company with a 100% interest in a silver/gold project at Kempfield NSW. Work is underway on the preparation of an EIS and a feasibility study for the first stage of the project which will involve heap leaching some 8.8 million tonnes of mainly oxide and transitional material to produce over 9.5 million ounces of silver and 15,000 ounces of gold over a 5 year mine life. Argent is also earning up to a 70% interest in two other NSW projects - gold at West Wyalong and base metals at Sunny Corner.
Argent Minerals Limited