Publication Details

Carr, P. F., Fanning, M., Jones, B. G. & Hutton, A. C. (2003). Geochronology of coal measures in the Sydney basing from U-Pb shrimp dating of airfall tuffs. 35th Sydney Basin Symposium on Advances in the study of the Sydney Basin (pp. 303-305). Wollongong, Australia: School of Geosciences, University of Wollongong.


Zircon-bearing rhyolitic and dacitic airfall tuffs in the Late Permian Sydney Basin coal measures provide ideal chronostratigraphic markers due to their widespread occurrence and rapid emplacement. SHRIMP U-Pb zircon dates for several stratigraphically-controlled airfall tuffs are consistent with their relative ages and biostratigraphic data, and indicate that the Illawarra Coal Measures accumulated in less than ~ 12 million years. Isotopic ages of the A waba Tuff and the Burragorang Claystone Member are indistinguishable within analytical uncertainty and support the correlation of these units proposed previously on the basis of geochemical fingerprinti~g. Deposition of coal-bearing sequences in the southern Sydney Basin apparently commenced a few million years before deposition of similar sequences in the Bowen Basin but deposition ceased at the same time in both regions.