RIS ID
9970
Abstract
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.
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.