The Icenian Crag of southeast Suffolk

• Published in: Philosophical Transactions of the Royal Society of London. B, Biological Sciences
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society 1974
• Subjects: Arctic
• Online Access: http://dx.doi.org/10.1098/rstb.1974.0039; https://royalsocietypublishing.org/doi/pdf/10.1098/rstb.1974.0039

Sections in the Icenian Crag at Chillesford, Aldeburgh, Thorpe Aldringham, Sizewell, Dunwich, Wangford and Southwold are described. Pollen and mollusc assemblages from these sites are tabled. The Icenian Crag is shown to contain a temperate pollen assemblage, resulting from a regional deciduous forest of the time. The assemblage is provisionally correlated with the Pastonian stage of the Middle Pleistocene, as Tsuga is very poorly represented and Abies is absent. The mollusc assemblages are divided into a sublittoral or infralittoral facies, a sheltered estuarine or wadden area facies, an open coast facies and a high-boreal or sub-arctic silty deposit facies, probably infralittoral. The unconformable relation of the Icenian Crag to Red and Coralline Crags at Chillesford and Aldeburgh and to Baventian sediments at Easton Bavents indicates a strong marine transgression over Lower Pleistocene deposits in Pastonian times. The beach plain of the Westleton Beds is included within this transgressive phase. Pollen assemblages from deep boreholes at Sizewell and Southwold show that the transgression deposits overlie Lower Pleistocene sediments correlated with the PreLudhamian, Thurnian and Baventian stages. A correlation is suggested between the Pastonian and the Cromerian III Interglacial of the Netherlands.