A critical evaluation of pollen-stratigraphic investigations of pre-Late Devensian sites in Scotland

Abstract

This paper reviews pollen-stratigraphic evidence from proposed interglacial and pre-Late Devensian interstadial sites in Scotland. The paper has two major parts. In the first the stratigraphic details of each of the sites are summarised and discussed. The sites are classified as ‘interglacial’ or ‘interstadial’ according to the interpretations adopted by recent authors, though as discussed in later sections such distinction is problematic and somewhat arbitrary. In the second part general problems of interpretation are discussed in the light of the stratigraphic details. Problems of dating and correlation are severe since most of the sediments lie close to or beyond the limit of conventional radiocarbon dating. Thus the normal approach has been to use pollen-stratigraphic comparisons with type-sites in southern or eastern England. This practice is considered questionable. Problems of assessing the provenance of pollens and spores are perhaps even more important, and at some sites are so severe as to render pollen assemblages of limited value. The problems discussed are: (a) secondary reworking of pollen; (b) long-distance wind transport of nonregional pollen; (c) pollen deterioration and (d) low pollen concentrations. Many of the problems discussed are of general significance being applicable to late Quaternary pollen diagrams from other regions. In the concluding section of the paper certain procedures are proposed that may permit a clearer assessment of potential problems of taphonomy in pollen stratigraphy.