L008 seismic survey of the Nerrima Dome, WA, 1953

Brief description

This report contains the results of a seismic survey on the Nerrima Dome, a major structure within the Fitzroy Basin and near its south-western boundary. The dome is situated near the Fitzroy River about 100 miles south-east of Derby in the West Kimberley district of Western Australia. The Nerrima Dome has been mapped at the surface in Permian sediments and is a complex structure. It was desired to determine if the dome existed at depth and, if not, the structure at depth, with a view to locating a site for a deep drilling test. The target beds for such a test are Devonian and/or Ordovician sediments over which the Permian sediments are believed to lie unconformably. Reflection methods were tried and proved unsuccessful and the survey was carried out using refraction methods. Although the structure underlying the dome has not been clearly shown, the refraction method has indicated that it is complex and does not conform with the domal structure at the surface. There appears to be a major unconformity at comparatively shallow depth (2000 ft). The deep structure (7000 ft) although apparently less complex than that immediately below the unconformity, also bears no obvious relation to structure at surface. The results so far obtained are reasonably conclusive in showing that no simple dome-like structure of large magnitude exists under the Nerrima Dome.

Lineage

Maintenance and Update Frequency: asNeeded

Statement: The oil possibilities of the Kimberley district of Western Australia were first recognised in 1919 when Harry Price, a well sinker, reported traces of oil in the area now known as Prices Creek. Subsequently, four bores were drilled in the Prices Creek area by Freney Kimberley Oil Company and three were reported to have disclosed traces of oil. Further traces of oil were reported in bores put down later by the same Company on the Mount Wynne and Poole Range Domes. Regional Geological mapping in connection with the search for oil has been carried out mainly by Dr Arthur Hade (1924 and 1934), Kraus and Findlay (1941-42), Dr Frank Reeves (1947-48) and more recently by a party of Bureau geologists (1948-1952). Other investigators have been in the area and contributed to the total knowledge but in general they have devoted their efforts to the study of particular problems or particular areas. The Nerrima Dome was located by Dr Wade. In 1939, the Freney Kimberley Oil Company commenced drilling on the Nerrima Dome at a site selected by Dr Wade. Owing to drilling difficulties and the war, the boring was stopped at 4271 ft. An attempt to deepen the well after the war was unsuccessful. In 1948, the Bureau carried out detailed geological mapping of the Nerrima Dome (Guppy, Cuthbert & Lindner, 1950) and in 1952 geophysical work was undertaken. A detailed Gravity survey over the Nerrima Dome was completed and a regional gravity survey of the Fitzroy Basin was commenced. A refraction seismic survey of Nerrima Dome was also completed and forms the subject of this report. The seismic survey was confined to the Nerrima Dome and covered an area of approximately 100 square miles between latitudes 18o 22'S and 18o 32'S and longitudes 124o 11 'E and 124o 33'E. Some additional test shooting was done outside this area in order to determine if conditions for the recording of reflections were similar to those within the area.