SUBMARINE GRAVITY SURVEYS IN ST. VINCENT GULF AND INVESTIGATOR STRAIT, SOUTH AUSTRALIA, IN RELATION TO OIL SEARCH
The APPEA Journal
5(1) 168 - 178
Published: 1965
Abstract
A total of 476 submarine and 307 coastal (beach) stations has been observed in and about St. Vincent Gulf and Investigator Strait. These were observed from the oceanographic vessel 'Saori' by manned sea-floor diving chamber, and/or scuba-operated encapsuled meter. Location control was by theodolite fix as from the shore and/or by sextant fix.The survey has provided Bouguer gravity station data contourable on 1 milligal intervals with an estimated maximum error of ± 0.3 milligals in the more remote seaward situations (principally due to surveying), down to ± 0.1 in closer inshore situations.
The survey has
defined the principal structural elements in and about St. Vincent Gulf and Investigator Strait;
defined the western margin of the Upper Proterozoic to Cambrian Adelaide Geosyncline;
provided a more detailed understanding of coastal block-faulting about the western escarpment of the Mt. Lofty Ranges;
defined a longitudinal series of gravitational maxima beneath the Orontes Platform which are predicted to relate primarily to Cambrian fold structures, and which are probably erosionally breached in the north;
outlined the probable margin of the submarine portion of the Troubridge (Permian) infra-basin;
located a gravitational cross-feature displaying a strong north-south gradient opposite Port Vincent that relates in part to the northern margin of the Troubridge Permian infra-basin, but which appears also to be a locus of transcurrent faulting displaying south-block-west movement;
subdivided the St. Vincent Basin into two provinces via a north-west-south-east structure extending south-east from about Macintosh Bank. Possible faulting in this zone indicates downthrow to the north defining potential southern limits of deeper Tertiary basin development.
https://doi.org/10.1071/AJ64029
© CSIRO 1965
