Groundwater origin and dating studies in Szigetkoz

High-resolution sedimentological and subsidence analysis of the Late Neogene, Pannonian Basin, Hungary

Detailed sedimentological and paleontological analyses were carried out on more than 13,000 m of core from ten boreholes in the Late Neogene sediments of the Pannonian Basin, Hungary. These data provide the basis for determining the character of high-order depositional cycles and their stacking patterns. In the Late Neogene sediments of the Pannonian Basin there are two third-order sequences: the Late Miocene and the Pliocene ones. The Miocene sequence shows a regressive, upward-coarsening trend. There are four distinguishable sedimentary units in this sequence: the basal transgressive, the lower aggradational, the progradational and the upper aggradational units. The Pliocene sequence is also of aggradational character. The progradation does not coincide in time in the wells within the basin. The character of the relative water-level curves is similar throughout the basin but shows only very faint similarity to the sea-level curve. Therefore, it is unlikely that eustasy played any significant role in the pattern of basin filling. Rather, the dominant controls were the rapidly changing basin subsidence and high sedimentation rates, together with possible climatic factors.