Wattle Dam Project
Introduction
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The Wattle Dam project is located 55km SW of Kalgoorlie within an area of documented nickel sulphide and gold mining activity. The project is located 15km NW along strike from the Widgiemooltha nickel mining centre and abuts or encloses the Armstrong, Andrews and 1A nickel sulphide mines.
The project was explored during the 1970s as part of an exploration push which discovered the Andrews Shaft (3/5D) underground nickel sulphide mine with a pre-mine resource of 660,000 tonne at 2.47% Ni. Other deposits, the 1A, 5A and 5B were identified, however with the establishment of the Andrews Shaft, systematic regional exploration apparently ceased.
Modern explorers have targeted the project principally for gold, providing a geological and geochemical framework to the area.
Latest Development by Pioneer
A programme of mapping and geochemistry is underway at Wattle Dam. This is rated as HIGH PRIORITY following the discovery of fresh Nickel Sulphides within a gossan sample.
A collaborative effort between prospector Mr Trent Stehn, joint tenement holder Ramelius Resources Limited and Pioneer geologists has resulted in the discovery of nickel sulphides in a gossan at Wattle Dam. Stehn alerted Pioneer to the gossan location and in subsequent sampling, weathered and fresh nickel sulphides have been identified. A sample is described as "A silicified, ferruginised gossan after Fe-Ni-Cu sulphides." The gossan is geochemically very anomalous, assaying 0.45%Ni, 0.24%Cu and 80ppb Pt+Pd ("PGM").
Soil Geochemisty and Mapping
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Following the completion of regional 200x50m soil sampling, a programme of detailed costean and grid geochemistry; and mapping was instigated, focussing on anomalous areas to evaluate as drill targets. Mapping and sampling is on-going.
Areas investigated include:
- Stehn's gossan location;
- 5B South prospect - the southern strike extension of the 5B Nickel sulphide deposit; and
- 5K prospect, with three ultramafic zones (thought to be structural repetitions of a single ultramafic unit).
Anomalous geochemistry coincides with basal contact positions.
During this programme 3,820 geochemical samples have been taken to date confirming 5 priority areas. In areas where the geology is amenable, detailed FLTEM surveys will be used to corroborate target models before drilling.
Aeromagnetic Survey
Detailed aeromagnetic data has been interpreted by Southern Geoscience Consultants. The interpretation, in conjunction with Pioneer mapping, is used to trace ultramafic stratigraphy, interpret the mineralised basal contact and identify possible accumulations of magnetic sulphide mineralisation.
Petrography
Pioneer's consultant describes the Stehn gossan sample as:
"Remnant sulphides consist of supergene pyrite pseudomorphing pyrrhotite. Former primary pentlandite (10%) as 2.0mm sized grains are thinly disseminated throughout the pyrrhotite and also form as narrow veinlets within the groundmass. A small number of remnant violarite patches up to 0.5mm in size are preserved within the sulphidic zone. Minor very fine aggregates of covellite after former chalcopyrite are associated with the violarite."
The discovery is of great importance as it is the first record of nickel sulphide mineralisation within Pioneer's Wattle Dam tenements.
Project Summary
Geological Setting
The Spargoville group is located at the northern end of the Widgiemooltha Greenstone Belt and consists of a belt of linear to slightly arcuate, tightly folded, mafic-ultramafic rocks and chert, on the southeastern flank of the Depot Dome.
The ultramafics correlate with the host units of the Mt Edwards, Widgiemooltha, Miitel and Redross Nickel Sulphide Mines.
The ultramafic rocks include spinifex textured komatiites, now altered to tremolite, chlorite and talc. Metasedimentary rocks close to the faulted contact with ultramafic rocks are laminated, micaceous, quartzo-felspathic siltstones with varying amounts of biotite, which defines a moderate foliation generally parallel to bedding. Metamorphosed felsic volcanics occur to the east.
The ultramafic sequence is repeated, due to folding or thrusting.
Exploration Activity
The Spargoville nickel sulphide deposits are located within two small excisions to Pioneer's tenements. These were discovered in the late 1960s by Selcast Exploration Limited, resulting in the construction of the Andrews Shaft which accessed the 5D deposit. Production took place between 1974-1979. Numerous other anomalies were detected and three smaller deposits, the 1A, 5A and 5B, identified. Recorded resources (including those mined) for the Spargoville nickel sulphide deposits total 1,200,000 tonne at 2.5% Ni. Much of the early geochemistry from drilling and costean sampling was not recorded or has been lost, however Selcast hole H309 returned 14.6m at 0.95% Ni and 0.014% Cu at 1Z and Spinifex RAB hole PNR031 returned 20m at 0.50% Ni and 0.024% Cu at 5N.
Based on current and historical production in the immediate vicinity of Wattle Dam, Pioneer rates this project very highly and has accordingly puts high priority on completing work programmes here.
Soil Geochemistry
A soil geochemistry survey comprising 1,006 samples was completed over the eastern ultramafic units, with results indicating anomalous areas with coincident, elevated Ni-Cu and PGE analyses.
Aeromagnetic Survey
A detailed aeromagnetic survey of the entire project has been completed and images received. An interpretation has been completed by Southern Geoscience Consultants. Data is interpreted for evidence of ultramafic stratigraphy, facing and possible accumulations of magnetic sulphides.
Moving Loop Electromagnetics
A 1,150 station MLTEM survey is complete with fifteen conductors modelled. The survey covered the eastern ultramafic units.
Reverse Circulation Drilling
Five RC holes were completed for a total of 894m. Four holes were drilled to reconcile TEM anomalies; and one specifically tested the 5J stratigraphy, including the nature of sulphides recorded in 1970s drill logs.
TEM anomalies drilled were explained by sulphidic black shales, however WRC008 at 5J encountered a high-magnesian komatiite, locally described as "Spotted Dunite", which is the host stratigraphy at all the Spargoville NiS mines. Importantly, this hole intersected a thin band of matrix sulphides at a sediment-free basal contact. Anomalous Ni results from drill samples are consistent with an endowed NiS environment.
