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On the Humberhead Levels between the Rivers Ouse and Trent, the former raised mires of Hatfield Moors and Thorne Moors have been studies using pollen analytical, stratigraphic and radiocarbon dating techniques. Pollen analysis of nine sites from both mires has revealed a series of changes in vegetation which can be attributed to the activities of people. A series of phases of agricultural activity have been delimited from the Bronze Age through to the Middle Ages. These periods of agricultural activity are separated by phases of forest or woodland regeneration. Five regional pollen assemblage zones have been proposed encompassing a period of time from c.4500 BP to c.500 BP.
Microstratigraphic study of the ombrotrophic peat from both mires has revealed a number of recurrence surfaces, of which the unhumified peat component corresponds to phase shifts to wetter mire conditions. These recurrence surfaces have been placed into five major groups which appear to reflect, in the main, deteriorations in the prevailing climate, although sea-level changes and autogenic vegetational processes are also of importance.
Macrostratigraphic investigation of both mires has enabled the peat deposits to be categorised into three distinct stages of mire development: rheotrophic, mesotrophic and ombrotrophic mire. Thorne Moors shows all three stages, although there are temporal variations in the initiation and persistence of these stages in different areas of the mire. On Hatfield Moors, only a very limited development of the first two stages was encountered, and ombrotrophic peats are dominant. The differences in ontogenesis may be due to hydroedaphic variations in the vicinity of each mire. Includes 'Appendix: radiocarbon dates from the Humberhead Levels' (97–100).
