Remapping of depth of e-log markers between Neogene basement and Lower/Upper Pannonian border in the Bjelovar Subdepression

Abstract

Within the Croatian part of the Pannonian Basin System, there are several depressions and subdepressions. A geostatistical analysis was performed in the Bjelovar Subdepression, which is part of the larger Drava Depression. Data for the analysis were obtained from structural maps of the subdepression, previously made by hand interpolation. Square grid cells (2 × 2 km) were laid over the maps. The analysis of cell data included a sufficient number of data (>700 per map) and the semivariogram analyses after which experimental and theoretical semivariograms were made. Consequently a new map set was interpolated by the Ordinary Kriging technique including the pre-Neogene palaeorelief border (‘Tg’) and e-log markers (‘Rs7’ and ‘Rs5’). New maps were subsequently compared with the older, hand-interpolated maps. It was shown that the method of transferring non-computer into computer interpolated maps via/using an artificial, regular grid of point data is an effective way of ‘digitizing’ older paper-based maps, preserving almost all of the regional information.