Permian limestone in the southeastern Bowen Basin, Queensland: an example of temperate carbonate deposition

Abstract

During the Permian the Bowen Basin, a foreland basin in eastern Australia, was influenced by cold to cool-temperate climatic conditions at a paleolatitude of 60 °S. Limestones are rare in the sequence except in the southeastern Bowin Basin area where two limestone-bearing sequences are present. The limestones are mainly skeletal grainstones and rarer packstones; skeletal grains include crinoids, bryozoans, brachiopods, molluscs, ahermatypic corals, foraminifera and sponge spicules. Crinoid remains are dominant, but brachiopod-rich and coral-rich limestones are present locally. Non-skeletal carbonate grains are absent from the limestones. Terrigenous components range from negligible to dominant. Comparison of the limestones with others in the Permian sequences in eastern Australia reveals a consistency in sedimentary style, the only variations being in the relative proportions of the skeletal fragments. The Permian limestones share similar characteristics with temperate Cenozoic limestones of New Zealand, suggesting that differences in carbonate sedimentation between tropical and non-tropical regions have been consistent through time and reflect real sedimentological differences.