Seismic reflection investigations of the Hellyer orebody and Que-Hellyer volcanics, North West Tasmania

Abstract

Two separate seismic reflection surveys have been conducted over Aberfoyle Resources Hellyer orebody and the enclosing Cambrian Que-Hellyer volcanics. The initial survey, conducted as a test case to determine if seismic reflection techniques could detect massive sulphide orebodies at depth, successfully identified the Hellyer orebody, which was found to have a characteristic seismic expression. Identification and mapping of stratigraphic units within the Que-Hellyer volcanics was also possible due to the good geological control available.The second survey did not successfully identify the Hellyer orebody, although some information relating to the structure of the enclosing basin could be inferred from the seismic data. Due to data degradation conventional seismic interpretation techniques could not be applied to the second survey.High resolution seismic surveys can detect massive sulphide orebodies if low velocity overburden problems are eliminated and high frequency data is collected. High resolution surveys can also provide structural and stratigraphic information between widely spaced drill holes in volcanic terrains.