Devensian Lateglacial and early Holocene floral and faunal records from NE Northumberland

Abstract

SUMMARY Radiocarbon-dated Late Devensian and early Holocene pollen, molluscan and ostracod assemblages, from the sediments of an infilled kettle-hole lake near Wooler in north-eastern Northumberland, are described and discussed in both a local and a wider context. During the Lateglacial interstadial, open birch woodland developed for a short time after herbaceous vegetation had first dominated the surrounding landscape. Scrub was present for the remainder of the interstadial. Mollusca and Ostracoda immigrated into the lake during the pre-woodland phase of the interstadial, then disappeared, perhaps due to a climatic deterioration. A depauperate fauna returned in the latter part of the interstadial, when a less hostile aquatic environment may have existed. In the succeeding Loch Lomond Stadial, a periglacial climate led to tundra-like vegetation and to the extirpation once again of the lacustrine fauna. In the early Holocene, Betula- then Corylus -dominated woodland was preceded by scrub and heath. Mollusca and Ostracoda recolonized the water body at the start of the Holocene, with the former quickly developing a diverse fauna. Two episodes of increased lake level with an intervening fall are suggested by the faunal assemblages. The second rise in water level was accompanied by vegetation changes in its environs, which may have been linked to a wetter and cooler climate than that which preceded it, and which occurred between 8000 and 7000 BP.