Evolution of Hungarian tectonics: an overview of a century of research on and around Lake Balaton

Abstract

Early concepts in Hungarian tectonics were born about a century ago as a result of exploration of Lake Balaton and its
surroundings conducted by Lajos LÓCZY.
The papers collected in the present volume deal with the tectonic studies of the past decade around Lake Balaton.
Therefore, it was considered necessary to review the early tectonic concepts in the light of contemporary knowledge in a
comparative manner. First, an overview of the fundamentals of the fixistic median mass (Zwischengebirge) concept is
given and its early mobilistic alternative is also presented. Some of the subsequent geological results favouring a mobilistic
interpretation are analyzed, and the major contribution of seismic surveys and deep drillings for establishing the Alpine
nappe structure of the Transdanubian Range is emphasized.
Another early concept explained the formation of the Pannonian Basin in terms of the subsidence of blocks bounded by a
longitudinal and a meridional set of faults. It was also thought that the present surface morphology, particularly a meridional
system of valleys and ridges, was controlled by these faults. An early alternative view rejected this block-faulting and, instead,
suggested regional scale-folding in the basin, and wind erosion as a primary mechanism of surface evolution. The new data
gathered on the neotectonic evolution of the Pannonian Basin relies on seismic mapping of the young deformational features
and the determination of the present day stress field. It is concluded that reactivation of Miocene synrift faults and/or
Cretaceous compressional detachment planes has occurred and has resulted in folding at the south-western periphery, and
regional strike-slip faulting all over the basin and surrounding mountains. Thus wind erosion as a main mechanism of
Holocene surface evolution in the Pannonian Basin can be regarded as undegoing a process of revival.