Annual and final report for EL 25691 Davenport Range 18 October 2007 to 18 October 2010

Abstract

Field exploration was undertaken in 2008 and 2010. The 2008 season focussed on a search for uranium, particularly of radiometric anomalies in the northwestern corner of the tenement, along Hatches Creek, where calcrete deposits were considered possible. ASTER multispectral (14 channels) satellite imagery was obtained and processed after the 2008 field excursion. Various channel mixes were displayed to provide pseudocolour and RGB images depicting a number of alteration and mineralisation styles, with a view to mapping mineralogical anomalies. A striking alunite anomaly was observed in the ASTER images. The Elkedra Dome is comprised of a perimeter ellipse of Coulters Sandstone, forming the hills of the Davenport Range, with a core comprised largely of dacite, rhyolite and ignimbrite of the Newlands Volcanics. In the north and northwest are an overlying sequence of mostly felsic Arabulja Volcanics. In 2008, four anomalies observed in airborne radiometric data were investigated on the ground. The investigation was performed with the assistance of a field gamma ray spectrometer, which was taken along the ground surface immediately below the flight lines. The anomalies were found to be over rhyolite ridges of the Arabulja Volcanics, rather than over valley calcrete. Four samples were taken, one at the most radioactive location on each anomaly. The eastern part of the tenement was visited in late May 2010, gaining access via Elkedra Homestead. This was to investigate the ASTER alunite mineralogical anomaly and the adjacent dacitic granophyre intrusion, considered as possible hosts for an economic mineral deposit. An unusual cobalt assay in the south of the tenement was also to be checked. Mapping was performed using held-held GPS instruments and uploaded into computers for processing and display with Mapinfo. The GDA94 datum, zone 53 was used at all times. Altogether, 51 soil geochemical and 18 rockchip samples were taken for assay, and later analysed in Perth using ICP-MS and ICP-OES methods for a total of twenty elements, being Au, Ag, As, Bi, Ca, Co, Cr, Cu, Fe, Hg, In, Mn, Mo, Ni, Pb, Sb, Te, Tl, U, W and Zn. None of the assay results showed better than trace amounts of gold, base metals or uranium. In particular, the 'cobalt' anomaly in the southwest of the tenement was shown to have less than 1ppm of the element. The tenement was relinquished in July 2010.