Two potential source rock zones occur within the Neogene sedimentary fill of the Pannonian basin. These units may be up to one kilometer thick, but the average organic carbon content is relatively low (0.5-1.5010). The upper zone (in the upper part of the lower Pannonian, s. l.) has just entered the oil generation window, but the lower zone (in middle Miocene to lower Pannonian rocks) passed into the oil generation window at around 8 Ma, and in the deepest parts of the basin it is already overmature. This second zone is significantly overpressured, and is estimated to have become overpressured initially at about 8 Ma. Combining maturation histories with coeval estimated pore pressures in the Makó-Hódmezővásárhely trough indicate that within this deeper zone of potential source rocks: (1) migration out of the upper part of the source rock zone was upwards and laterally, while (2) migration out of the middle and lower parts of this zone was probably downwards out of the source rocks and then laterally within more permeable rocks below.
Figures & Tables
The Pannonian Basin: A Study in Basin Evolution
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.