Geological maps of neogene sediments in the bjelovar subdepression (northern Croatia)

Abstract

The methods applied in this paper constitute the conventional (without software packages) interpolations in subsurface geological mapping that pertain to basin analysis of the Bjelovar Subdepression in northern Croatia. The Bjelovar Subdepression covers about 2900 km2, which is the scale of small basins within the Pannonian Basin System. The maps were constructed by interpolation of six stratigraphical and lithostratigraphical markers. These maps form the basis for explanations of (1) deposition and deformation evolution of sediments and structures, (2) spatial distribution of possible hydrocarbon traps and (3) evaluation of location of mature source rock. There are mapped large unconformities, especially in the eastern portion of the subdepression, two main synclines (western and eastern) and several anticlines (Pavljani, Dežanovec). Fault activity was easily observed, and the slight domination of normal faulting was proven in Badenian-Early Pontian (16.4-6.3 Ma) ages, and reverse faulting in the Late Pontian-Quaternary (6.3-0.0 Ma). Maximum throws were up to 300malong some stratigraphical borders.