Dolomitization as an eventualdetermining factor in the colour alteration index (CAI)

Abstract The Colour Alteration Index of conodonts (CAI) is indicative of the degree of alteration of organic material that exists in the interior of the conodonts. This CAI is used ordinarily in the determination of paleotemperatures. More frequent findings of abnormally high CAI values, equivalent to paleotemperatures that are not compatible with temperatures obtained by other more trustworthy methods, has taken us to use values not superior to 6 for the establishment of paleotemperatures. The CAI values measured in specimens proceding from dolostones in the Iberian Range (Spain) show in this way a certain degree of incompatibility with geological data. These anomalous values are the conse…