Isotopes in palaeoclimatology and palaeoecology

Abstract

The importance of isotope analysis for the reconstruction of palaeoclimates and the achievement of palaeoecological information has already been mentioned in previous chapters. Since the basic work of Urey and his associates in the 1950s, extended studies have been carried out taking into account new data and problems arising from the further development of the methods. The estimation of palaeotemperatures by measuring the oxygen isotope ratios of CaCO₃ from marine fossils had great consequences for interpreting the history of climatic change of Earth, although it has turned out that palaeotemperatures have to be interpreted carefully if reliable data shall be obtained. Unrealistic results can derive from various factors such as salinity, diagenetic alteration of the samples, ice volume effects, mixing with fresh water, life habits, biological fractionation or mineralogical structure of the CaCO₃. Although these parameters might influence and limit the value of temperature determinations, each one of them gives opportunities for deriving more palaeoecological information, especially if comparable data gained through faunal or floral analysis are available.