Present Status and Applications of the Astronomical (Polarity) Time Scale for the Mediterranean Late Neogene

Following the initial tuning of late Pliocene-Pleistocene \delta¹⁸O records from the open ocean, the astronomical time scale was extended to the base of the Pliocene, using sedimentary cycle patterns observed in land-based marine sections from the Mediterranean. Here I will present a review of the progress subsequently made in establishing an Astronomical (Polarity) Time Scale (A(P)TS) for the Mediterranean Neogene by our research group and (inter)national collaborators. Firstly, the astronomical time scale has been extended back to 13.6 Ma. Secondly, this time scale has been evaluated and the accuracy of astronomical solutions quantitatively assessed by means of a detailed statistical comparison of precession/obliquity interference patterns in climatic proxy records and astronomical target curves. Thirdly, the existent Messinian gap in the time scale has been closed, showing that the onset of the Messinian sa-linity crisis started at exactly the same time all over the Mediterranean. Fourthly, the continental record is increasingly being incorporated, allowing detailed "bed-to-bed" correlations with the marine record and extension of the APTS back to 13 Ma. Fifthly, ⁴⁰Ar/³⁹Ar dating of volcanic ash beds intercalated in astronomically dated successions aims at the intercalibration of astronomical and radio-isotopic time. Sixthly, identification and astronomical tuning of Milankovitch-type of cyclicity facilitates detection of sub-Milankovitch cycles both in the marine and in the continental record. Seventhly, climate modelling is applied to get a comprehensive understanding of climate system(s) responsible for sedimentary cycle formation in the Mediterranean late Neogene. Finally, the influence of longer-term astronomical cycles which operate on tectonic time scales has been evidenced and the astronomical time scale has been successful applied in studies of seafloor spreading rate histories.