Ref ID : 3298
Louis Beyens; On the subboreal climate of the Belgian Campine as deduced from diatom and testate amoebae analyses. Rev.Palaeobot.Palynol. 46:9-31, 1985
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A peat core from the valley of the Mark river was analyzed for its pollen and diatom content. The diatom spectra from the Subboreal part formed a series in which the successive assemblages revealed a lowering of the water-level (decreasing percentages of planktonic forms), and an evolution in the water from a somewhat more alkaline to an almost neutral condition. This is correlated with an increase in oligotrophic and oligotrophic-mesotrophic species. These phenomena are explained as the consequences of the flooding of the fen by the more alkaline and eutrophic river water, after which the stagnant body of water returned to its former hydrological state. Another peat core originates from a bog located in the dune belt along the same river. It was investigated for its pollen, diatoms and testate amoebae. Testate amoebae enabled the author to detect an oceanic phase in mid-Subboreal times, during which the bog surface was subaquatic in summer. It would appear that the flooding in the valley and the wet phase in the bog are synchronous. Extrapolation of radiocarbon dates enabled this oceanic phase to be dated. As a result the Subboreal climate in the Belgian Campine can be subdivided into three periods: (1) from +/-4680 B.P. until +/-4350 B.P.: continental phase with dry summers; (2) from +/-4350 B.P. until +/-4075 B.P.: an oceanic phase; (3) from +/-4075 B.P. until at least 3200 B.P.: renewed continentel conditions.