Palaeoenvironmental reconstruction of the Younger Dryas in Jersey, UK Channel Islands, based on plant and insect fossils

Abstract

Plant and insect remains from sand and organic silt intercalated with solifluction deposits, the silt dated to an approximate 230 radiocarbon-year period during the first part of the Younger Dryas Stadial of the Devensian Lateglacial, are described and discussed. The sand and silt were deposited into water and onto wetland under a periglacial climatic regime, probably by a combination of slope wash and a snow-melt stream. Pollen, plant macroremains and Coleoptera allow the inference of an arctic-alpine environment with a mosaic of vegetation communities including dwarf-shrub heath, herb-rich grassland and wetland. The insect assemblage is used to calculate the mean temperature of the warmest month (T-Max) at between 9degreesC and 13degreesC and the mean temperature of the coldest month (T-Min) at between -20degreesC and -3degreesC. These are the first unequivocal lithostratigraphical, biostratigraphical and chronostratigraphical data concerning the Devensian Lateglacial in the UK Channel Islands. They are compared with similar information from northern France, northern Belgium, The Netherlands, southern England and South Wales.