Neotectonics and the preglacial landscape of eastern Norfolk, UK

The British Geological Survey (BGS) borehole database, relevant maps, and the Memoirs have been researched in order to deduce, by recording the elevation of the base of the Happisburgh and Corton Formations, as much as possible about the preglacial (Cromerian) landscape of eastern Norfolk. A relatively flat low-lying landscape is revealed, with the position of the shorelines during marine highstands before the first glaciation, and what appear to be associated relic regressive surfaces, located. With a W-E trending fault located just north of Norwich, there is also evidence of a neotectonic uplift probably related to that found in the pre-Anglian Bytham valley. But north of the fault the uplift in land level is less, but still consistent with neotectonism consisting of a “tipping” process towards the North Sea sedimentary basin. Evidence for buried fluvial systems has been found, including possible precursors of the current Yare and Wensum rivers. A tentative chronology based on proposals advanced by other workers is presented and its limitations explored. The effect of the karstic surface of the Chalk on interpretation of Crag sequences is also considered.