Exploration of three small licence subareas located near Cleve, Rudall and Verran has targeted possible Palaeoproterozoic stratiform or hydrothermal base and precious metal deposits hosted within Hutchison Group metasediments. Interpretation of...
Exploration of three small licence subareas located near Cleve, Rudall and Verran has targeted possible Palaeoproterozoic stratiform or hydrothermal base and precious metal deposits hosted within Hutchison Group metasediments. Interpretation of 1979 Pancon-flown detailed aeromagnetic data defined five discrete magnetic anomalies that might represent buried volcanogenic magnetite / sulphide - bearing bodies, possibly later remobilised within Lower Proterozoic metasediments. Two of the anomalies were selected to undergo grid-based ground magnetic surveys and magnetic source body modelling. They were Cleve anomaly 3, where previously CRA Exploration had obtained a banded iron formation outcrop rock chip assay of 0.57 g/t Au, and Cleve anomaly 5, located along strike from an abandoned copper mine dug into poorly outcropping schistose ironstone beds. In July 1997, Platsearch also commissioned contract detailed geological mapping, plus reconnaissance calcrete and soil geochemical sampling on 500 m centres, which resulted in the delineation of several low order gold anomalies which appeared to be related to BIF facies and cross-cutting quartz veins. Follow-up soil sampling of ridges and spurs then ensued to confirm anomalies with >10 ppb Au. After Acacia Resources (later part of Anglogold Australasia) took up a joint venture with Platsearch on 24/8/99 and assumed licence operatorship, additional soil and rock chip sampling was carried out, before the completion of five short RAB drilling traverses (20 holes totalling 1038 m) to test some gold anomalies associated with the Cleve anomaly 3, one having up to 1.92 g/t Au plus 1780 ppm Cu from a brecciated ironstone gossan, that lay along an interpreted NW-trending mineralised structure. No significant bedrock mineralisation was located by this drilling (the best drillhole intercept being 4 m @ 0.36 ppm Au below 12 m depth in 99RUDR016). Other small gold-in-soil anomalies, detected by sampling on 200 m centres at the Yadnarie and Silver Monarch prospects, were targeted next by Anglogold, who conducted RAB drilling on three short traverses at Yadnarie (17 holes for 669 m) plus 2 holes (129 m) on a single traverse of Silver Monarch. Again, no appreciable bedrock mineralisation was encountered (best result 15 m @ 0.35 g/t Au in hole 99RUDB023 at Yadnarie prospect). Re-logging and re-assaying of the Lower Proterozoic drill core section in the former WMC DDH SJCD2 (34 samples taken over the depth interval 663-696.5 m) confirmed the existence at depth in the Rudall magnetic anomaly region of slightly haematite - altered and silicified Hutchison Group chemical metasediments containing trace sulphide veinlets carrying no significant metal values. On 14/8/2000, Anglogold elected to exit the joint venture, due to the results so far achieved not supporting the likelihood of identifying an exploration target in the Rudall area that was suited to its corporate strategy. No subsequent field work was performed by Platsearch during the remaining four years of its tenure of EL 2790, prior to this second partial relinquishment event.
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