Results of earlier stable isotope studies on lamprophyre-carbonatite bodies and red calcite dykes in the Transdanubian Mid-Mountains are summarized in this paper. Their genetics have similarities in that they were formed during the Cretaceous and that magmatic fluids presumably played a significant role in the formation. A tentative model is proposed in which magmatism and magmatic fluid circulation would appear in the Transdanubian Mid-Mountains in different forms depending on spatial and/or temporal positions; i.e. emplacement of mantle-derived lamprophyre-carbonatite bodies during the Middle-Upper Cretaceous that induced carbonate vein formation and formation of red calcite dykes of Aptian to Campanian age that show magmatic delta-13C and deltaD signatures and can be related to movements of deep-seated igneous fluids
