The Sydney Basin crops out along the eastern coast of New South Wales for about 200 km to both the north and south of Sydney. It comprises a succession of Permian and Triassic marine and non-marine, cold-climate, clastic sedimentary rocks, together with a series of intrusions and extrusions which were emplaced during several magmatic episodes. The formation of the Sydney Basin in the Late Palaeozoic was caused by a multistage process of cratonic accretion in the Lachlan Fold Belt, followed by subsidence as part of a foredeep basin. A mid-Permian period of diastrophism produced the New England Fold Belt and the final structure of the Sydney Basin.
Initial development of the Sydney Basin comprised a shallow rift system accommodating a coal measure sequence in the southern part of the basin whereas marine and volcanic units were emplaced to the north. The sag phase of Sydney Basin development led to a major transgression, with superimposed eustatic sea level variations, during the deposition of the predominantly marine Shoalhaven Group in the mid to Late Permian. Volcanism and emplacement of igneous intrusions in the Late Permian heralded the subduction associated with the docking of the New England Fold Belt. The latter event caused thrusting and uplift to the northeast of the Sydney Basin that resulted in the southward extension of deltaic and terrestrial volcanolithic facies, including major coal seams, into the Sydney Basin. This loading in the foredeep resulted in depression of the depocentre and the eastward extension of quartz-rich facies across the basin from the Lachlan Fold Belt. Later igneous activity occurred sporadically through the Mesozoic and Tertiary.
Geology research on the Sydney Basin undertaken at the University of Wollongong has been directed at determining the geological history of the basin with emphasis on the tectonic and structural development, volcanic history, timing and petrogenesis of igneous rocks, sedimentation, palaeoenvironment, faunal studies and coal resources. Excellent exposures together with access to drill cores have permitted study of the three-dimensional architecture of the succession. This research activity has involved a number of staff members including Paul Carr (igneous rocks), Brian Jones (sedimentology), Adrian Hutton (sedimentology and coal) and Chris Fergusson (structural geology) and many Honours and postgraduate theses but numerous avenues of research await investigation.
Major themes of research include:
Igneous geochemistry
Magma emplacement
Interactions between igneous extrusions and sedimentary facies
Correlation and geochronology of tuffs
Coal petrography and coal depositional environments
Shallow marine sedimentary successions, shelly and trace fossils
Terrestrial-marine interactions in the sedimentary record, including eustatic sea level changes
Terrestrial sedimentary facies
Sequence stratigraphy and basin analysis
Structural analysis and tectonism
