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  • Legacy product - no abstract available

  • The Sydney Basin extends for 380 km along the east coast of New South Wales south of latitude 32°S, and has an onshore area of about 36 000 km2 . About 4800 m of Permian and Triassic sedimentary rocks are preserved in the basin which lies between the New England and Lachlan Fold Belts. The study of the Sydney Basin by the Sedimentary Basins Study Group of the Petroleum Exploration Branch of the Australian Bureau of Mineral Resources was undertaken in co-operation with the New South Wales Department of Mines, who prepared a 1:500 000 geological map (PI. 1). The study has required constant exchange of ideas and information with petroleum exploration companies and the Department of Mines. In addition to the authors of this Bulletin the following members of the Sedimentary Basins Study Group since late 1966 have contributed to the study: D. J. Forman, M. A. Reynolds, K. G. Smith, R. Bryan, A. R. Jensen, P. J. Alcock, P. J. Hawkins, R. B. P. Pitt, S. Ozimic, J. I. Raine, K. Rixon, and B. G. West.

  • The Australian Calibration Line (ACL) , with a total gravity interval of 3 Gal, was established during 1970 between Laiagam in Papua New Guinea and Hobart in Tasmania. During 1973 the Australian Bureau of Mineral Resources and the USSR Geodesy and Cartography Survey made joint observations along the full length of the ACL. Measurements made with eight Soviet GAG-2 gravity meters established a gravity scale for Australia to an accuracy of 2.5 parts in 105. This scale and a datum of 979 671.86 mGal for Sydney A were adopted for Australia in 1973. The Soviet scale established for the ACL appears to be within 1 part in 104 of both the IGSN71 scale established for the Western Pacific Calibration Line by absolute determinations, pendulum measurements and international gravity meter comparisons, and the scale established for the Soviet Calibration Line by OVM pendulums. The Soviet scale for the ACL defines a milligal which is 1.5 parts in 104 larger than that defined by IGSN71 values for the ACL, and 5 parts in 104 larger than the 1965 Mean Australian Milligal that was used as an Australian milligal standard between 1965 and 1973. Both of these scales are partly based on Cambridge pendulum measurements made in Australia during 1950-51. These measurements are now thought to have been incorrect in scale. LaCoste, Romberg gravity meters have been used during six surveys along the whole or part of the ACL. The LaCoste observations have been reduced using the Soviet ACL scale and the new datum for Sydney A. The most probable values for airport gravity stations, calculated from the LaCoste results, have a precision of better than 0.01 mGal and are consistent to within experimental error with values calculated from the GAG-2 results. LaCoste observations reduced using the Soviet ACL scale give more accurate values for the gravity differences of the main intra-city ties and calibration ranges along the ACL.

  • The R502 series of maps has been replaced by the National Topographic Map Series (NTMS). The R502 series consists of 542 map sheets and covers Australia at a scale of 1:250,000. It was compiled from aerial photography, but only about one quarter of the series was contoured. The standard sheet size is 1 degree of latitude by 1.5 degrees of longitude. Transverse Mercator map projection and Clark 1858 datum were used. Coverage of the country was completed in 1968.

  • The International Map of the World (IMW) series is no longer maintained, and printed copies of this map are no longer available. The Australian portion of the series consists of 49 maps. They were produced to an international specification using the R502 series at 1:250,000 scale as source material. Production commenced in 1926 and was completed in 1978. The maps were revised from time to time and the last reprint was undertaken in 2003. Each standard map sheet covers 4 degrees of latitude by 6 degrees of longitude and was produced using a Lambert Conformal Conic projection with 2 standard parallels. The series has recently been superseded by the 1:1 000 000 topographic map general reference.

  • The International Map of the World (IMW) series is no longer maintained, and printed copies of this map are no longer available. The Australian portion of the series consists of 49 maps. They were produced to an international specification using the R502 series at 1:250,000 scale as source material. Production commenced in 1926 and was completed in 1978. The maps were revised from time to time and the last reprint was undertaken in 2003. Each standard map sheet covers 4 degrees of latitude by 6 degrees of longitude and was produced using a Lambert Conformal Conic projection with 2 standard parallels. The series has recently been superseded by the 1:1 000 000 topographic map general reference.

  • The R502 series of maps has been replaced by the National Topographic Map Series (NTMS). The R502 series consists of 542 map sheets and covers Australia at a scale of 1:250,000. It was compiled from aerial photography, but only about one quarter of the series was contoured. The standard sheet size is 1 degree of latitude by 1.5 degrees of longitude. Transverse Mercator map projection and Clark 1858 datum were used. Coverage of the country was completed in 1968.

  • The R502 series of maps has been replaced by the National Topographic Map Series (NTMS). The R502 series consists of 542 map sheets and covers Australia at a scale of 1:250,000. It was compiled from aerial photography, but only about one quarter of the series was contoured. The standard sheet size is 1 degree of latitude by 1.5 degrees of longitude. Transverse Mercator map projection and Clark 1858 datum were used. Coverage of the country was completed in 1968.

  • The radiometric, or gamma-ray spectrometric method, measures the natural variations in the gamma-rays detected near the Earth's surface as the result of the natural radioactive decay of potassium, uranium and thorium. The data are collected on airborne geophysical surveys conducted by Commonwealth, State & NT Governments and the private sector.