Degradation of the wetland sediment archive at Star Carr: an assessment of current palynological preservation

Abstract

This paper presents the results of an investigation into the preservation status of pollen and other microfossils in the organic sediments at the wetland Mesolithic site of Star Carr. This study assesses the degradation of the pollen record in a profile at the edge of the archaeological site, adjacent to previous pollen work carried out from 1989 to 1991 and using it as a benchmark for comparison. There has been a severe degradation of pollen grains since the earlier work, with the upper peat devoid of pollen and the lower part of the organic profile badly affected. Only the very basal sediments retain well preserved pollen. Comparisons with hydrological and geo-chemical data obtained by other workers during the assessment of the Star Carr site suggest that oxidation caused by drainage and dessication of the organic sediments, perhaps originating in fissures in the drying peat, is a primary cause of the observed severe deterioration of the pollen record. Non-pollen palynomorphs (primarily fungal and algal spores) appear to be better preserved than pollen in the present bio-stratigraphic record, showing little surface degeneration, but are not recorded in the earlier work. The pollen archive in organic sediments at the Star Carr site is now badly damaged. Any further pollen work there should be undertaken urgently but is probably not justifiable.