Contribution of Seismic Reflection Data to Chronostratigraphy of the Pannonian Basin

Abstract
Available magnetostratigraphic and radiometric age data for Neogene sedimentary rocks within the Great Hungarian Plain can be shown to be consistent with each other if primary seismic reflectors are interpreted as geological time lines. Using this premise, we argue that the boundary between the lower and upper Pannonian (s. I.) units is diachronous and varies from 9 Ma to about 7 Ma. Lithogenetic units, determined by analyzing the trend of lithologic development in drill holes, and the correlation of these units by reflection seismic data provide a means of dividing the lower Pannonian into three subunits ⁠. By combining age data with these correlations, the unconformity between synrift and postrift sediments can be shown to represent a time gap of one to several million years in many places in the Pannonian basin. The Pannonian basin system is an integrap part of the Alpine mountain belts of east-central Europe. It is completely encircled by the Carpathian Mountains to the north and east, the Dinaric Alps to the south, and the Southern and Eastern Alps to the west. In 1912, Kober defined the Pannonian basin as one of the type “Zwischengebirge,” a relatively un-deformed region characterized by block faulting and situated between externally vergent thrust belts. More recent studies using subsurface data have shown that the Pannonian area was extensively deformed by Mesozoic thrusting and subsequently disrupted by a complex system of Cenozoic normal and wrench faults. Thus, the Pannonian “massif” has undergone several types of deformation, which are partly hidden by a thick sequence of sedimentary rocks of Neogene-Quaternary age. The Pannonian basin is actually a system of small, deep basins separated by relatively shallow basement blocks. The Neogene-Quaternary sedimentary rocks exceed 7 km in thickness in some areas, and the basin system (including the Transylvanian basin) is about 400 km from north to south and 800 km from east to west. It is currently interpreted by most workers as a Mediterranean back arc extensional basin of the middle Miocene age. The Carpathians, Eastern Alps, and Dinarides, which surround the Pannonian basin, are the result of Mesozoic and Cenozoic continental collision between Europe and several continental fragments to the south, including Africa. Thrusting was direted outward from the present Pannonian basin toward the European platform and the Adriatic region. In all the orogenic belts, the interior parts of the thrust belts were deformed in Mesozoic time, while the outer parts were deformed in Tertiary time. The volume presents 26 papers and eight regional maps resulting from a joint five-day symposium held in Veszprem, Hungary, in 1982 entitled “Evolution of Extensional Basins within Regions of Compression with Emphasis on the Intra-Carpathian Region.” The symposium was sponsored jointly by the Hungarian Oil and Gas Trust, the Hungarian Geological Survey, and the U.S. National Science Foundation.

This publication has 0 references indexed in Scilit: