Integrating magnetostratigraphy,biostratigraphy, cyclostratigraphy and seismic data to obtain a high resolution stratigraphic record: a case study from the Vienna Basin

摘要

We have developed an integrated methodology to obtain a high resolution stratigraphic record that assists in evaluatingthe relative contributions of tectonics, eustacy, and other factors to sedimentary basin infills. The approach combinesmagnetostratigraphic and biostratigraphic analyses of well data to form a basic chronostratigraphic framework. Seismicdata are included to refine the time lines by taking into account unconformities and faults that cause time gaps. These aresubsequently corroborated by detailed analysis of electrical borehole images. The latter, having a vertical resolution of about1 cm, are used to perform a spectral frequency analysis in order to identify cyclicities in the sedimentary record. Using thechronostratigraphic framework, the cyclostratigraphic analysis is well constrained and can provide a temporal resolutionthat lies significantly higher than the Milankovitch cycles. This methodology is demonstrated with a dataset from a boreholein the Central Paratethyan Vienna Basin. Focusing on the Upper Sarmatian, the approach described above resulted in accu-rate chronostratigraphic age dating, the identification and location of time gaps caused by unconformities and faults, andan accurate sedimentation rate for this stage. The cyclostratigraphic results indicate that a strong allocyclic orbital forcingwas superposed on the overall tectonic evolution of the basin.