Pollen profile from Wurzacher Becken

Interglacial lacustrine sediments of 0.3-0.6 m thickness are found in the basin of Wurzach over a distance of about 9 km as detected by 5 borings. The interglacial bed is intercalated between lacustrine sediments of Würm (above) and glaciolacustrine sediments of the Younger Riss (below). Most of the Würmian sediments are silty-sandy, calcareous and varved deposits. They were deposited as bottom sediments of a delta, which had formed in the glacial lake filling the Wurzach basin during the Upper Würm. The terminal moraine of the Younger Riss is found in the N and S of the Reed of Wurzach. In the NE it is overlain by sediments of Würm and Holocene age. The pollen bearing part of the new profile represents the last interglacial period (except its earliest phases), the two Lower Würm interstadials, which are equivalents of the Brørup and Odderade interstadial phases, and a third interstadial, the Dürnten, known from other localities in the forelands of the Alps with a forest vegetation, which consisted mainly of spruce and larch trees, and the intercalated stadial phases. These interstadials are different from those described earlier by FILZER, which on the contrary represent cold periods with highly increased reworking of pollen. The equivalents of the Brørup, Odderade and Dürnten interstadials are the "Kiefer-Fichten-Kampfzeit" and part of the "Kiefernzeit mit Fichte" of FILZER. The characteristic series of climatic events known already from a great number of sites scattered all over Europe and again at Wurzach proves that the Riss/Würm- and the Eem interglacial periods are time-equivalents. Differing amounts of Carpinus and Abies at different places in the northern foreland of the Alps are related to the migration history of the two species during the last interglacial period and must not be used to distinguish different types of interglacials (type Zeifen, type Pfefferbichl).

Pollen profiles from 8 sediment cores from the Degersee, Southern Germany

The discovery of a neolithic pile field in the shallow water near the eastern shore of the Degersee confirmed earlier palynological and sedimentological studies stating that early man was active in the region since more than 6000 years. The already available off-site data were freshly assessed, completed by additional data from old and new cores and the interpretations revised. A common time scale for the off-site data and the on-site data was obtained by AMS dating of terrestrial macro remains of the neolithic section of off-site core De_I+De_H. The ages can thus be parallelled with AMS ages of construction timber on-site. Pollen analyses from all cores provide a further time scale. The continuously and densely sampled pollen profile of the profundal zone embracing the entire Late glacial and Holocene serves as a reference. From the Boreal onwards the relative ages are transformed by AMS ages and varve counts into calibrated and absolute. A transect cored close to the neolithic pile field across the lake marl-platform demonstrates its geological architecture in the shallow water since the Lateglacial. Studies of the microfabric of thin sections of drilled cores and of box cores from the excavations demonstrate that neolithic settlements now at 2-3,5 m water depth had been erected on lake marl freshly fallen dry, thus indicating earlier lake levels dropped by 1.5-2 m. The neolithic section of the highly resolved off-site profile in the lake=s profundal zone has laminated and calcareous zones alternating with massive ones. Assemblages of diatoms and concentrations of trace elements changing simultaneously characterise the calcareous sections as deposits of low lake levels that lasted between some 40 and more than 300 years. The ages of discovered lake shore dwellings fall into calcareous segments with low lake levels. From the end of the Upper Atlantic period (F VII) appear Secondary Forest Cycles in the beech forest, a man-made sequence of repeated vegetational development with an identical pattern: With a decrease of beech pollen appear pollen of grasses, herbs and cultural indicators. These are suppressed by the light demanding hazel and birch, those again by ash, and finally by the shade demanding beech forming a new pollen peak. Seven main Forest Cycles are identified In the upper Neolithic period each comprising some 250, 450 or 800 years. They are subdivided into subcycles that can be broken down by very dense sampling in even shorter cycles of decadal length. Farming settlers have caused minor patchy clearances of the beech-mixed-forest with the use of fire. The phases of clearance coincide with peaks of charcoal and low stands of the lake levels. The Secondary Forest Cycles and the continuous occurrence of charcoal prove a continued occupation of the region. Together with the repeated restoration of the beech climax forest they point to pulsating occupation probably associated with dynamic demography. The synchronism of the many palynological, sedimentological and archaeological data point to an external forcing as the climate that affects comprehensively all these proxies. The fluctuations of the activity of the sun as manifested in the residual d14C go largely along with the proxies. The initial clearances at the begin of the forest cycles are linked to low lake levels and negative values of d14C that point to dry and warm phases of a more continental climate type. The subcycles exist independent from climatic changes, indicating that early man acted largely independent from external forces.

Pollen record and age determination of a sediment profile from Schmiechener See, Germany

Die untersuchten Schluffe und Kiese sind unter kaltzeitlichen Bedingungen in einem See mit Schwimmpflanzengesellschaften abgelagert worden. Zur Sedimentationszeit gab es in der Umgebung des Sees eine tundrenartige Vegetation, die auch Steppenarten enthielt.