Middle to late Pleistocene palaeoecological reconstructions and palaeotemperature estimates for cold/cool stage deposits at Whittlesey, eastern England

Fossiliferous beds in a complex sequence of late Middle to Late Pleistocene deposits at Whittlesey, eastern England, provided a rare opportunity for a multidisciplinary study of the palaeoecology of cool/cold stage deposits from different glacial stages. The fossiliferous sediments investigated form part of the River Nene 1st Terrace. Three of the four fossil assemblages investigated pre-date the last interglacial stage (Ipswichian/Eemian/marine oxygen isotope stage (MIS) 5e), whereas the other dates to part of the MIS 3 interstadial complex (Middle Devensian/Weichselian). Pollen, plant macrofossil, molluscan, coleopteran, ostracod, foraminifera and vertebrate data are available to a greater or lesser extent for each cool/cold stage assemblage, and they broadly present the same ecological picture for each one: a continuum from low-energy permanent to non-permanent aquatic habitats through marshland with associated waterside taxa, together with flood influxes of fluvial, riparian and ruderal taxa. Although each fossil assemblage records cool/cold climatic conditions, to a greater or lesser extent, these conditions are more apparent in the insect and ostracod faunas. In comparison with results published for the Last Glacial Maximum (LGM) stadial in The Netherlands, palaeotemperature estimates based on ranges of mutual agreement between independent coleopteran and ostracod methods for the three pre-Ipswichian/Eemian assemblages indicate minimum mean July air temperatures that are from +1° to +3 °C warmer, but January values that embrace the −8 °C estimate for the LGM. There is, however, a disparity between the coleopteran and ostracod palaeotemperature estimates for the Middle Devensian/Weichselian fossil assemblage, which are based on two different sample stratigraphic levels; the lower, coleopteran assemblage is indicative of very cool, continental climates, whereas the stratigraphically slightly higher ostracod assemblage suggests a climatic amelioration. Lack of numerical age-estimates prevents a robust stratigraphical interpretation, but the youngest pre-Ipswichian/Eemian fossil assemblage could date to the MIS 7–6 transition, at a time when cooling possibly preceded glacially driven sea-level fall. It is apparent from the rich coleopteran data that some continental cold-indicator taxa also appeared in pre-Ipswichian/Eemian cold stages and therefore assignment of continental cold-indicator taxa to particular Devensian/Weichselian intervals should be undertaken with care

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

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