The Bureau of Mineral Resources, Geology & Geophysics (BMR) (now Australian Geological Survey Organisation), Commonwealth Department of Primary Industries & Energy, conducted the Gunnedah Basin Seismic Survey during January to April 1991. The major aim of the seismic survey was to record deep seismic reflection data across the Gunnedah Basin and bounding margins. The seismic survey would also address several problems relating to the geometry of structural units and major faults.
The location of the seismic line was determined in consultation with explorationcompanies and the NSW Department of Minerals and Energy (now Department of Mineral Resources). Factors controlling the positioning of the seismic line included the location ofexisting roads and tracks, avoiding surface basalts where possible, and ensuring the primary scientific objectives of the survey were targeted.
The deep seismic reflection survey by the BMR recorded 253 km of 8-fold CMP seismic data. The continuous seismic line, BMR91.G01, was quite crooked in places due to access problems in state forests and the extremely hilly area between Manilla and Uralla. LineBMR91.G01 crossed major geological features including the Gilgandra Trough, Rocky Glen Ridge, West Gunnedah Sub-basin, Boggabri Ridge, Mules Creek Sub-basin, Mooki Fault,and the Tamworth Belt, Peel Fault and Tablelands Complex within the New England Orogen.To generate a multi-disciplinary dataset, gravity observations were made at 360 m intervalsalong the seismic line, and the seismic line was also flown using the BMR geophysicalaircraft to record aeromagnetics and raliometrics.
The seismic data have been processed, with the data showing good seismic reflectionimages of the main structural features targeted in the seismic survey. The seismic data will be interpreted to construct revised geological models of the Gunnedah Basin and adjacentbasement terranes.
