Penfold Nickel Project
 |
|
Click image to enlarge
|
The Penfold Project covers an estimated 48 strike kilometres of under explored mafic-ultramafic stratigraphy within the Coolgardie and Kambalda domains. Both the Coolgardie and Kambalda domains have demonstrable endowment of komatiite - hosted nickel sulphides, with the Kambalda domain having produced more than 1 million tonnes of Ni metal.
 |
|
Click image to enlarge
|
The ultramafic sequences within the Penfold Nickel Project have close similarities in komatiite composition, stratigraphic relationships and age to the adjacent nickeliferous camps at Kambalda, Widgiemooltha and the Nepean deposit south of Coolgardie. Given the corresponding geological setting of the Penfold Project ultramafic sequences to those of proximal nickel camps, it is believed there is a similar probability of the project having nickel sulphide occurrences.
The Abattoir Prospect on Location 53 is the obvious target for immediate exploration, with historic diamond drilling intercepts of 15.2m @ 0.64% Ni and 6.1m @ 1.88% Ni (including 3m @ 3.1% Ni + Cu) to be confirmed by the first phase of drilling.
The effectiveness of previous nickel exploration also requires critical assessment. In areas of outcrop, surface exploration techniques (such as geological mapping and prospecting, costeaning and geochemical sampling) have been effective in identifying outcropping mineralisation. The main phase of nickel exploration in the 1960’s and 1970’s identified areas where these techniques were likely to be successful. The ultramafic sequences are known to extend under cover along strike from outcrops (from the aeromagnetic data), where surface sampling techniques employed by earlier explorers were less effective due to the lack of geochemical indicators in transported surface material. Where drilling was employed, the drilling methods were often ineffective in providing meaningful samples in areas of high water table, soft clays or broken, indurated zones within the regolith.
 |
|
Click image to enlarge
|
There has been a lapse of thirty years in systematic exploration for nickel sulphide mineralisation within the project area (a period during which gold was the commodity of interest), during which time exploration technology has enjoyed significant advances in drilling and geophysical techniques, and many areas under cover can now be effectively assessed to depths of 200-300m. Further, there is now a greater awareness of the importance of the regolith environment when analysing geochemical surveys and a willingness to drill to bedrock in
 |
|
Click image to enlarge
|
areas where reliable geochemical information is required. Opportunities for exploration success exist where the ultramafic sequences are situated under transported cover. In these areas shallow mineralisation, extending into the regolith may have gone unrecognised. Similarly, deeper targets, represented by mineralisation below the base of weathering and having no surface geochemical expression are also likely to have been overlooked.
In summary, the main exploration features of the Penfold Nickel Project are:
- The ultramafic sequences are believed to have the same age, stratigraphic association and composition as ultramafics hosting the Kambalda - Widgiemooltha nickel camps and the Nepean nickel deposit. On this basis the potential for nickel mineralisation occurring within the Penfold Project is considered to be high.
- Historic exploration concentrated around areas of outcrop; ultramafic sequences under cover were generally not as effectively explored due to limitations in drilling equipment and geophysical surveying techniques.
- Nickel sulphide mineralisation identified in an unusual setting at the Abattoir Prospect has not been explored conclusively.
- The greatest potential remains for the discovery of mineralisation under transported cover and/or deeper mineralisation occurring below the depth of weathering.
- Detailed mapping and re-interpretation of local stratigraphic younging directions since the nickel boom era indicate that opportunities exist for further testing of basal contact positions. For example, the basal contact of the Horseshoe ultramafic sequence may have been mis-interpreted by earlier explorers as a hangingwall contact.
