Final report for the 12 month period 29 October 2009 to 28 October 2010

Abstract

Walhallow EL 25917 comprising 500 blocks was divided on a 3 kilometre by 3 kilometre grid across the tenement for 175 sample point locations. Access was mainly by bore tracks and fenceline tracks that accessed the majority of the tenement. Inaccessible areas were not sampled. The survey took 28 days, using a four wheel drive vehicle, across the majority of the tenement for a total of 149 samples. Samples were labeled with the WAL prefix with each weighing approximately 500 grams, sieved to -1mm and placed in a labeled plastic cliplock bag. Sample locations were determined by a handheld Magellan MAP 330M handheld GPS. Sample locations were relocated from transported soils areas to residual soil areas. Nodules and pisoliths were noted in the soils and removed by sieving. Rock samples of all lithologies on the tenement were analysed in the field and slabbed specimens were analysed using a Nikon SMZ800 binocular microscope in the West Perth geology office. All lithologies confirmed the 1:250,000 SE53-7 Wallhallow geology nomenclature. A short description of the sampled soil and its geological environment also noting the nature, distribution and genesis of regolith types and the relationships between the various regolith units and the association with the underlying bedrock. At every site a reading was taken of the soil to be sampled by a scintillometer. An average was taken of readings every 10 seconds for as long as it took to take the sample. Scintillometer readings were also taken at selected outcrops, such as the calcareous grey siltstone, mottled saprolitic fossiliferous siltstone, ferruginous and massive white sandstones and various laterites in different stages of weathering. Results indicate all samples returned a range of concentrations from very low to average abundance across all elements assayed. Rock samples were identified as the average lithologies and nothing of interest was noted. Scintillometer counts indicated average to below average background levels. There are 4 dominant regolith profiles that cover the tenement, these being red-brown fine to medium grained transported quartzose sands; residual grey-brown to yellow-brown soils some with high percentages of lateritic pebbles derived from the weathering of Cretaceous sediments; the residual friable black soils that form over the Cretaceous massive grey calcareous siltstones, and laterite capping formed over the Lower Cretaceous sediments. Baryte nodules occurring in limonitic siltstones within the Cretaceous grey siltstone were a function of surface weathering and concentration. No other concentrations of sulphide or oxide were noted. Geochemical soil analyses have shown that across a variety of surficial environments and contacts, there were no elevated elemental values that exceeded general background levels for the given rocktypes and their residual soils. Sampling on major structural dislocations failed to find any elemental concentrations. On the basis of field reconnaissance and laboratory geochemical results, it is recommended EL 25917 be relinquished in its entirety.