Zonal Distribution of Carbon Isotopes in Supergene Calcite Crystals from the Dal'negorsk Deposit, Primor'e Region

摘要

Study of the geochemistry of stable isotopes can efficiently solve issues of the genetic mineralogy only if we can define the sources of matter involved in mineral formation. The present paper reports original data on the distribution of carbon isotopes in two types of supergene calcite. Calcite of type 1 was sampled from stalactites in karst cavities in Triassic limestone blocks. Calcite of type 2 is a product of the reaction of wollas-tonite with CO_2-rich groundwaters. The isotopic composition of calcite was determined with a Delta+ Advantage (Thermo Finnigan) mass spectrometer. The accuracy of δ~(13)C determination was 0.07per thousand PDB. Material for the analysis was taken with a diamond drill 3.5 mm in diameter.