Techniques for validating the historic record of lake sediments. A demonstration of their use in the English Lake District

A lake sediment core from an upland catchment has been investigated in order to determine the nature of the anthropogenic record, and to demonstrate technques by which historic can be validated. The core was subjected to chemical analysis (major elements and selected trace metals), and sequential extractions. Two unrelated anthropogenic events were recorded in the sediments: the onset of woodland clearance ca. 1000 BP and of lead mining ca. 800 BP. Major element profiles indicating erosion rates can be validated using supporting organic carbon data, and the historic record of trace metal inputs can be validated by comparison of sequential extraction results expressed as percentages of total metal at each depth, with the results of similar non-pollutant species.