Lichenometric Chronology and Archaeological Features on Raised Beaches: Preliminary Results from the Swedish North Bothnian Coastal Region

Abstract

Growth rates for Rhizocarpon geographicum (L.) D.C. and Rhizocarpon alpicola (Hepp.) Rabh. have been studied at different locales on the Swedish North Bothnian Coast. Shore displacement rates have been used to date maximum thallus diameters of lichens growing on cobble and boulder beaches (wave-washed moraine) at increasing elevations above mean sea level. Linear growth rates have been observed for the period ca. 200 to 1400 BP. These results, in combination with general shore chronology and radiocarbon dating, will be used for determining the ages of coastal archaeological features. Lichenometry may well prove to be an invaluable archaeological and historical tool within the Bothnian and Baltic coastal regions.