Landslides in the Sydney Basin - Geoscience Australia

Seismic Hazard in SydneyProceedings of the one day workshopoccur to the north and south and which mark the edges of the two plateaux, the Hornsby andWoronora Plateaux. To my knowledge these structures, which by my suggestion of formation aremainly contemporaneous with the major formation of the Lapstone structures, show no evidence ofreverse movement on any large scale. The curvature of these structures as they swing easterly seemsto conform with a fairly simple pattern of downdragging of the central basin (Figure 3).Although it might be simplistic, one would expect a strong thrusting from the west to producesympathetic curving of faults westerly at the north and southern extensions of a strong north-southtrending thrust, rather than what we now map.CONCLUSIONSThere is much still to learn about the structural nature and tectonic history of the inner (andtotal) Sydney Basin. It is pleasing that this task is being taken up with vigour by geologists andgeophysicists. It will surely bear fruit and contribute to the raising of safety standards withinand extending beyond the metropolis, particularly with respect to seismicity.REFERENCESAndrews, E.C., 1910. The Tertiary unity of eastern Australia. Journal and Proceedings of the RoyalSociety of New South Wales, 44, 420 - 480.Bembrick, C.S., Herbert, C., Scheibner, E. and Stuntz, J., 1973. Structural sub-division of the NewSouth Wales portion of the Sydney – Bowen Basin. New South Wales Geological SurveyQuarterly Notes 11, 1 – 13.Branagan, D.F., 1975. Further thoughts on the Lapstone Structure. 10th Symposium on Advances inthe Study of the Sydney Basin, Abstracts. Department of Geology, University of Newcastle,22 – 23.Branagan, D.F., 1977. Faults in the Hawkesbury Sandstone, 1977 11th Symposium on Advances inthe Study of the Sydney Basin, Abstracts. Department of Geology, University of Newcastle,20.Branagan, D.F., 1985. An overview of the geology of the Sydney Region. In Pells, P.J.N., (ed.)Engineering Geology of the Sydney Region. Rotterdam: Balkema, 3 – 48.Branagan, D.F., 1991, Pyrmont Geology. 25th Symposium on Advances in the Study of the SydneyBasin. Department of Geology, University of Newcastle, 162 – 169.Branagan, D.F., 2000a. The Hawkesbury Sandstone: its origins and later life.In G.H. McNally andB.J. Franklin (eds.) Sandstone City (Sydney’s dimension stone and other sandstonegeomaterials). Monograph No. 5, Environmental, Engineering and Hydrogeology SpecialistGroup, Geological Society of Australia, 23 – 38.Branagan, D.F., 2000b. Structural Geology of the Hawkesbury Sandstone, with particular referenceto the city of Sydney and nearby areas. In G.H. McNally and B.J. Franklin (eds.) SandstoneCity (Sydney’s dimension stone and other sandstone geomaterials). Monograph No. 5,environmental, engineering and Hydrogeology Specialist Group, Geological Society ofAustralia, 39 – 54.Branagan, D.F., Mills, K.J. and Norman, A.R., 1987. Sydney Faults – Facts and Fantasies. 22ndSymposium on Advances in the Study of the Sydney Basin. Department of Geology,University of Newcastle, 111 – 118.Branagan, D.F. and Mills, K.J., 1990. Some newly-exposed faults in the Sydney Region. 24thSymposium on Advances in the Study of the Sydney Basin. Department of Geology,University of Newcastle, 105 – 111.Branagan, D.F. and Norman, A.R., 1984. Sydney Faults: More conundrums? 18th Symposium onAdvances in the Study of the Sydney Basin. Department of Geology, University ofNewcastle, 125 – 12.11