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    Correlation of uppermost Devonian and Lower Carboniferous miospore zonations in Byelorussia, Poland and western Europe
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    Abstract The stratigraphical occurrence of 38 Upper Devonian miospore taxa is compared to some miospore and conodont zones in 28 intercalibrated levels. The accurate position of 15 miospore First Occurrence Biohorizons and one Last Occurrence Biohorizon in terms of the conodonts available in a few regions of western Europe is discussed in detail and their correlation evaluated.
    Conodont
    Devonian
    Citations (39)
    During the late Famennian, quantitative palynology allows four continental ecological niches to be recognized, three marine megaenvironments and two kinds of contrasting palynofacies (oxic/anoxic). Applied to a restricted marine back-barrier setting during a maximum of a regression peak (Ourthe Valley, Eastern Belgium), such analysis suggests two kinds of cycles: 1) recurrence of wet climates developing upstream swamp margin plant communities, 2) recurrence of high sea-levels developing downstream “coal” swamps. These are 6th order cycles i.e. of less than 100 ka and do not introduce any significant long-term change in the continental vegetation. Applied to a latest Famennian sequence around the Hangenberg Event in Sauerland, Germany, where the changes in sea-level are known to have been severe, the same kind of analysis suggests a higher rate of sedimentation than in the Ourthe Valley and short cycles involving climatic changes and sea-level changes, probably also of the 6th order. Continental vegetation has not been strongly affected by the Hangenberg Event sensu stricto (the base of the Hangenberg Black Shale). On the contrary, younger “continental Hangenberg events”, corresponding to the peak of the regression, probably associated with a much wetter climate, have strongly modified the contemporaneous “upland” and “coastal” plant communities. The “coastal” one has not recovered after that peak, probably as a consequence of a colder climate (BRAND, 1993). The duration of the Hangenberg Events (corresponding to the miospore LN Zone) was probably less than 100 ka as also suggested by SANDBERG & ZIEGLER (1996). The consequence is that the glacial episode known in Brazil, which is characterized by the same miospore Zone, had also a very short duration. Latest Famennian climate was probably unstable with quick oscillating cold (or glacial) and temperate (or interglacial) phases in the high latitudes.
    Swamp
    Palynofacies
    Continental Margin
    Marine transgression
    Coastal plain
    Citations (26)