Relinquishment report for EL 8189, 6 October 2005

Abstract

All activities in the reporting period centred on site investigations for the proposed expansion of the McArthur River zinc-lead deposit from the existing underground mine to a large scale open cut operation which would require significant civil works prior to the commencement of mining. This would include the diversion of the McArthur River and Barney Creek, the construction of a levee around the perimeter to retain flood waters during a 1 in 500 year event and the construction of an emplacement facility to contain waste rock. These investigations were undertaken by Golders Associates on behalf of civil designers, Kellogg, Browning and Root (KBR) and Environment Engineers (URS) to assist in the process of finalising the Environmental Impact Study, and comprised geotechnical, geophysical and hydrogeological studies, including: - Drilling and sampling of 26 geotechnical boreholes, totalling 360 metres, diamond drilled at least 3 metres into weathered bedrock; - Hydrogeological drilling, sampling and falling head permeability tests of 20 probe holes and 4 monitoring bores within the alluvium adjacent to the McArthur River; - Groundwater sampling and analysis; - Borehole geophysical logging; - Excavation and sampling of 64 test pits for construction material availability; - 9.15 km of geophysical seismic refraction survey to accurately map depth to bedrock along the centrelines of the diversion channel and bund wall; - Insitu permeability testing; - Laboratory testing.