Abstract Lake-floor morphologies may be significantly different from seafloor topographies
of other basins, typically observed in passive or active continental margins. The
bathymetry of large paleo-lakes is often overwritten by subsequent tectonic evolution,
burial beneath thick overburden and inherent compaction effects. We study the evolution
of such an initial underfilled, balance fill and finally overfilled large paleo-lake
basin by the interpretation of 2D and 3D seismic data set corroborated with calibrating
wells in the example of the Neogene Pannonian Basin of Central Europe. Lake Pannon
persisted for about 7–8Myr and was progressively filled by clastic material sourced
by the surrounding mountain chains and transported by large rivers, such as the paleo-Danube
and paleo-Tisza. We combined sedimentological observations with a backstripping methodology
facilitated by well lithology and porosity data to gradually remove the sediment overburden.
This approach has resulted in a morphological reconstruction of the former depositional
surfaces with special focus on the prograding shelf-margin slopes. Our calculations
show that the water depth of the lake was more than 1000m in the deepest sub-basins
of the Great Hungarian Plain of the Pannonian Basin. The significant compaction associated
with lateral variations of Neogene sediment thicknesses has created non-tectonic normal
fault offsets and folds. These features have important effects on fluid migration
and hydrocarbon trapping. We furthermore compare the geometries and effects of such
non-tectonic features with the activity of larger offset sinistral strike-slip zones
using 3D seismic attributes.
