THE DEVELOPMENTAL HISTORY OF SCRAGH BOG, CO. WESTMEATH AND THE VEGETATIONAL HISTORY OF ITS HINTERLAND

Stratigraphical, macrofossil and pollen analytical studies on the sediments of Scragh Bog, a small fen in central Ireland, are described. The Flandrian pollen diagram is divided into local pollen assemblage zones which in turn are related to the zones of Mitchell (1956). The Ulmus‐Quercus‐Alnus assemblage zone of the Atlantic period is proposed as a regional assemblage for base‐rich areas in Ireland as distinct from the Alnus‐Quercus‐Pinus regional assemblage of Jessen (1949). The changes associated with the Elm decline are considered in detail. The subfossil records, which are not abundant, include Acrocladium giganteum and Sphagnum contortum from the Late‐glacial and Antitrichia curtipendula and Isothecium myosuroides, both probably from zone VIIIa. The depositional processes in the basin and the vegetational history of the hinterland are reconstructed. The nature of Landnam and the possibility of in situ survival of the present‐day fen communities are discussed.