Cyclostratigraphy and sequence stratigraphy of the Solent Group (Eocene-Oligocene) of the Isle of Wight, UK

A stratigraphic reinterpretation of the Eocene-Oligocene Solent Group is presented here, based on the Whitecliff Bay section of the Isle of Wight, Hampshire Basin, UK. High resolution palaeontological, sedimentologica and mineralogical analyses allow the establishment of facies groups, which are used to demonstrate the presence of seven conspicuous sequences. For the first time, these are tied to an accurate magnetostratigraphic framework. Investigation of the cyclic signal in clay mineralogical data reveals that sea level was controlled by the ~400ka cycle of astronomical (Milankovitch) forcing at this critical period in Earth history, when the change from a greenhouse world to an icehouse world took place. This has also allowed uncertainty surrounding the location of the Eocene-Oligocene boundary within the Solent Group to be cleared up. A major incision event associated with glacial build up at the Eocene-Oligocene boundary is recorded, but is smaller than that predicted by isotope records (Miller et al. 1991), possibly as a result of rapid subsidence rates