Paleogene igneous activity along the easternmost segment of the Periadriatic-Balaton Lineament

Abstract

In the Pannonian Basin three Paleogene igneous regions can be outlined, namely the Zala Basin Shear Zone, the Velence Mts and the Recsk Region. These igneous regions are aligned along the easternmost Periadriatic-Balaton Lineament System.  The igneous bodies are built up mostly by effusive rocks (andesite, dacite and basaltic andesite); however, intrusive rocks (tonalite, diorite) have been identified as well. The radiometric age of the effusive and intrusive rocks is scattered around 30 Ma, which falls into the range of the igneous bodies aligned along the Periadriatic Line (Bergell, Adamello, Riesenferner, Karawanke, etc.). Nevertheless, an Eocene onset of the magmatic activity in the Pannonian Basin is accepted on the basis of biostratigraphic data. As major and trace element composition range of the Paleogene igneous suites in the Pannonian Basin are basically the same, they are thought to have undergone the same pre-crystallization history. Geochemical characteristics of these calc-alkaline igneous r...