Copyright © 197,5, The Society of Economic Paleontologists and Mineralogists SPARIT IZAT ION OF A PELLETED L IMESTONE: A CASE STUDY OF CARBON AND OXYGEN ISOTOPIC COMPOSIT ION 1

ABSTRACT: Carbon and oxygen isotopes in limestone behave differently during epigenetic processes. In comparison with the carbon, which remains unchanged in nonrecrystallized samples, the oxygen usually equilibrates with ground water. Samples containing sparites formed by recrystallization are characterized by very low (negative) /~C values. The values obtained indicate that sparitization occurred in the presence of water having carbon and oxygen isotopic compositions imilar to recent fresh water sources from the same area. I NTRODUCTION The carbon and oxygen isotopic composition of ancient limestone may change during epi-genesis or may continue to reflect the sedi-mentary environment in which it formed. The data availahle (Keith and Weber, 1964; l)egens and Epstein, 1964; Fritz, 1967; Fontes, et al., 1970; Tan and Hudson, 1971) show that 81sO values of ancient limestone are consis