Pollen and land-snail analysis of calcareous soils

Recently, pollen analyses have been undertaken on a number of soil profiles, mostly Neolithic land surfaces on the Chalk, which have been investigated by molluscan analysis. The two methods often give discrepant conclusions. For instance, the molluscs at Windmill Hill suggested woodland whereas the pollen indicated farmland. A number of such cases are considered, and explanations put forward for some of them. The different nature of pollen grains and snail shells may be reflected in their persistence in the soil, pollen being ephemeral (and therefore more or less co-eval) in these base-rich soils, whilst shells may be more persistent. The two methods, therefore, could be reflecting different phases of ecological history, with the pollen reflecting the latest—and perhaps transient—phase.