Some Australian Oxygen Isotope Temperatures and a Theory for a 30-Million-Year World-Temperature Cycle

Oxygen-isotope temperatures are reported for living shells from Davis Base (Antarctica), Macquarie Island, and Victoria, and for fossil Australian shells from the Holocene to the Paleozoic. A summary is made of paleotemperatures during the Jurassic, Cretaceous, and Tertiary from which the possibility of a 30 m.y. temperature cycle is suggested. An explanation of this cycle in terms of the atmospheric CO₂ content is discussed, which may be extended to give an explanation of glacial ages.