Figure 3. Stable carbon vs. oxygen isotopes of the host rocks, brachiopods and the major cement generations of the La Vid Group. The limestone and the majority of the dolostone values in the shaded boxes show only a slight early diagenetic overprint in comparison to the brachiopod data from Ala (1996). The brachiopods should reflect the composition of seawater carbonates at the time of their deposition (Popp, 1986). The arrows indicate an alteration of the limestones and the brachiopods samples, which lie outside of the dark shaded box, as well as of S-Dol 1, towards the depleted d¹³C-values of Cal 3.