Fractionation of O¹⁸/O¹⁶between Coexisting Calcite and Dolomite

Abstract

The writers determined $$\delta O^{18}$$ and $$\delta C^{13}$$ of coexisting limestone and dolomite samples from several localities in the upper Mississippi Valley zinc-lead district and found little fractionation in mineral pairs. This is in conflict with the data obtained from Leadville, Colorado, from a higher temperature environment. Until these differences are better understood, $$\Delta_{calicite\_dolomite}$$ should not be used as a substitute for $$\Delta_{calcite-quartz}$$ as a geologic thermometer.