Abstract
Synopsis: The most successful application of oxygen isotope studies on fossils has been the elucidation of the relationship between temperature changes, glaciation, and the isotopic composition of the oceans during the Pleistocene, from analyses of planktonic and benthonic foraminifera. This work is now being extended into the earlier Cenozoic, and is revealing the history of the accumulation of the Antarctic ice, and much else about Cenozoic climates. A review of the principles, limitations and future promise of the method is given by critically comparing some recent contributions.