Early phase ductile deformation elements in the limestone of the eastern part of the Bükk Mts, Hungary

Abstract

In the Paleozoic and Mesozoic rocks of the Bukk Mountains the imprints of a polyphase deformation and an anchi-epizonal metamorphism were observed. The physical conditions of this metamorphism were the same as that of the earliest, ductile deformation phase. The imprints of later deformation phases can generally be distinguished by their tectonic style. Our investigation was focused on the style of folding and on the different textural elements of limestone which developed during the early deformation phase. According to lithologic conditions and geographical position, the folds show a certain style variety. The multilayer fold geometry depends on the thickness ratio and the competence contrast between the layers. In the occurrence of different textural patterns the position within a fold and the pre-deformational grain size play an important role. The main deformation mechanism in the fine-grained matrix was pressure solution, while coarse-grained crystal aggregates show signs of dynamic recrystallizatio...