U–Pb geochronology and palynology from Lopingian (upper Permian) coal measure strata of the Galilee Basin, Queensland, Australia

ABSTRACTThis study presents the first chemical abrasion-isotope dilution thermal ionisation mass spectrometry (CA-IDTIMS) U–Pb zircon ages from tuffs in Lopingian (upper Permian) strata of the Galilee Basin, Queensland and reassigns the B coal-seam to the ‘Burngrove Formation equivalent.’ Five Lopingian tuffs were dated: four from the CRD Montani-1 drill hole including three from the ‘Fair Hill Formation equivalent’ (255.13 ± 0.09, 254.41 ± 0.07 and 254.32 ± 0.10 Ma) and one from the ‘Burngrove Formation equivalent’ (252.81 ± 0.07 Ma, approximately the age of the Yarrabee Tuff in the adjacent Bowen Basin); and a single tuff from the Black Alley Shale in the GSQ Tambo-1-1A drill hole (254.09 ± 0.06 Ma). In the Galilee Basin, all three units are constituents of the Betts Creek Group, here formally elevated in nomenclatural status from the Betts Creek beds. On the western margin of the basin, the group thins, and the ‘J and K’ seams (formerly known as the Crossmore and Glenaras sequences, respectively) in th...