Time calibration of sedimentary sections based on insolation cycles using combined cross-correlation: dating the gone Badenian stratotype (Middle Miocene, Paratethys, Vienna Basin, Austria) as an example

Cross-correlation between insolation intensities and a combination of sedimentary characters is introduced to obtain precise time calibration of sedimentary cycles. The first step is to transfer the section scale into ages using power spectra comparing the main periods with orbital cycles, while in the second step the standardized values of sedimentary signals are cross-correlated with the standardized insolation curve. As an example for the applicability of the method, we investigated calcium carbonate, organic carbon in a 9-m sampled section from the historical Badenian stratotype at Baden/Sooss (Lower Austria). Comparing courses of geochemical parameters between the historical stratotype and a nearby drilled 102-m scientific core resulted in continuation of the core section into the stratotype. Cross-correlation between magnetic susceptibility (MS) combined with the negatively correlated calcium carbonate content of the drilled section on the one side and summer solar insolation at 65 northern latitude on the other resulted in an extremely significant correlation between -14.221 and -13.982 Ma. This is younger than the before estimated time frame (-14.379 to -14.142 Ma) based on cross-correlation between MS and the orbital 100-kyr eccentricity and 41-kyr obliquity cycles. The direct continuation of the drilled section by the stratotype covering a time span of 17.7 kyr consequently dates the Badenian stratotype between -13.982 and -13.964 Ma. Therefore, the upper limit of the stratotype, assigned to the Early Badenian, puts it close to the Langhian/Seravallian boundary at -13.82 Ma, demonstrating the need for revising the Badenian stratigraphic subdivision based on orbital cycles, especially the middle Badenian Wielician substage.