Editorial to the special Special Volume of Global and Planetary Change “Coupled Deep Earth and Surface Processes”

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 7–8 Myr 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 1000 m 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.