Tectonically-determined distribution of monogenetic volcanoes in a compressive tectonic regime: An example from the Pannonian continental back-arc system (Central Europe)

This paper presents the results from a geographic information systems (GIS) workflow, which was used to analyze the spatial distribution and temporal evolution of volcanoes in the Mio-Pleistocene monogenetic Bakony-Balaton Highland Volcanic Field (BBHVF), located in the Pannonian Basin, Hungary. Volcanism occurred during the tectonic inversion in a back-arc setting and a compressive/transpressive tectonic regime on the hottest and thinnest lithosphere of continental Europe. The main goal of this study is to clarify the effect of the pre-existing structure of the upper lithosphere in the distribution of the volcanic centers across the volcanic field using an innovative GIS methodology. Orientation of the volcanic field was compared to the orientation of the faults in the BBHVF, and in its larger vicinity, which resulted in correspondence, suggesting the dominance of the SW-NE direction. The directions of the volcanic lineaments fit well to the two main fault directions. The fault-volcano proximity analysis suggests that the fault plane of a thrust fault was an important structural feature during the lifespan of the volcanism. All results suggest that the fault plane of a regionally significant Cretaceous thrust fault (Liter Fault) might have served as a temporary pathway for the ascending magma, whereby (similarly to other, smaller faults) redirecting the magmas causing clustering of the volcanoes. This highlights the importance of major upper crustal structural heterogeneities for magma transport in a compressive tectonic system, especially in the case of active, monogenetic volcanic fields from a volcanic hazard perspective. The present GIS workflow can be effective in analyzing the spatial patterns of the volcanism and its connection with crustal structures at monogenetic volcanic fields worldwide.