Palynological record of Lake Nero in Russia

This collection prepared to IX Congress of INQUA containes 25 articles concerning general and regional problems of Pleistocene. The chronological scale of the Late Pliocene and Pleistocene, climatical cycles and methods of the absolute dating are considered. Some data obtained by means ef paleomagnetic, thermoluminescence and radiocarbon methods at several point sections (Likhvin, Rostov-Jarosiavsky, Priasovje, Ob-garm, Chagan, Pryobskoje Plateau, Lower Volga) are given.

Pollen and spore deposition in different areas of the Lena Delta

Studies of the annual pollen and spore deposition in different areas of the Lena Delta were undertaken for the first time in the Asian sector of the Arctic during the Russian-German ''LENA 98'' and ''LENA 99'' expeditions in the framework of the International ''Laptev Sea System-2000'' Project. To achieve this objective, three spore-pollen traps were set up along the meridional delta profile in accordance with the European Pollen Monitoring Programme for the period July 1998 to August 1999. A comparison between the results of spore-pollen analysis of the contents of traps and the surrounding vegetation was performed. The results confirmed the current spore-pollen spectra are comprised both of pollen and spores of the local plants and of long-distance pollen and spores. The dependence of the long-distance pollen deposition on the character of the wind regime of the region was established. The prevailing southerly and southeasterly wind direction determines the main pollen influx of tree species from the areas of their growth south of the delta. The features of the morphological structure and fossilization of pollen and the features of the productive capability and plant growing conditions are of large significance in the pollen transfer and deposition.

Pollen and macroremains from four profiles from site Samerberg 1

Pollen and macrofossil analysis of lake sediments revealed the complete development of vegetation from Riss late-glacial to early Würm glacial times at Samerberg (12°12' E, 47°45' N, 600 m a.s.l) on the northern border of the Alps. The pollen bearing sediments overlie three stratigraphic units, at the base a ground-moraine, then a 13 m thick layer of pollen free silt and clay, and then a younger moraine; all the sediments including the pollen bearing sediments, lie below the Würm moraine. The lake, which had developed in an older glacial basin, became extinct, when the ice of the river Inn glacier filled its basin during Würm full-glacial time at the latest. One interglacial, three interstadials, and the interdigitating treeless periods were identified at Samerberg. Whereas the cold periods cannot be distinguished from one another pollenanalytically, the interglacial and the two older interstadials have distinctive characteristics. A shrub phase with Juniperus initiated reforestation and was followed by a pine phase during the interglacial and each of the three interstadials. The further development of the interglacial vegetation proceeded with a phase when deciduous trees (mainly Quercus, oak) and hazel (Corylus) dominated, though spruce (Picea) was present at the same time in the area. A phase with abundant yew (Taxus) led to an apparently long lasting period with dominant spruce and fir (Abies) accompanied by some hornbeam (Carpinus). The vegetational development shows the main characteristics of the Riss/Würm interglacial, though certain differences in the vegetational development in the northern alpine foreland are obvious. These differences may result from the existence of an altitudinal zonation of the vegetation in the vicinity of the site and are the expression of its position at the border of the Alps. A greater age (e.g. the Holsteinian) can be excluded by reason of the vegetational development, and is also not indicated at first sight from the geological and stratigraphical data of the site. Characteristic of the Riss/Würm vegetational development in southern Germany - at least in the region between Lake Starnberg/Samerberg/Salzach - is the conspicuous yew phase. According to absolute pollen counts, yew not only displaced the deciduous species, but also displaced spruce preferentially, thus indicating climatic conditions less favourable for spruce, caused by mild winters (Ilex spreading!) and by short-term low precipitation, indicated by the reduced sedimentation rate. The oldest interstadials is bipartite, as due to the climatic deterioration the early vegetational development, culminating in a spruce phase, had been interrupted by another expansion of pine. A younger spruce-dominated period with fir and perhaps also with hornbeam and beech (Fagus) followed. An identical climatic development has been reported from other European sites with long pollen sequences (see chapter 6.7). However, different tree species are found in the same time intervals in Middle Europe during Early Würm times. Sediments of the last interglacial (Eem or Riss/Würm) have been found in all cases below the sediments of the bipartite interstadial, and in addition one more interstadial occurs in the overlying sediments. This proves that Eem and Riss/Würm of the north-european plain resp. of the alpine foreland are contemporaneous interglacials although this has been questioned by some authors. The climax vegetation of the second interstadial was a spruce forest without fir and without more demanding deciduous tree species. The vegetational development of the third interstadial is recorded fragmentary only. But it has been established that a spruce forest was present. The oldest interstadial must correspond to the danish Brørup interstadial as it is expressed in northern Germany, the second one to the Odderade interstadial. A third Early Würm interstadial, preserved fragmentarily at Samerberg, is known from other sites. The dutch Amersfoort interstadial most likely is the equivalent to the older part of the bipartite danish Brørup interstadial.

Sedimentological and palynological analysis of sediment cores from the northeastern Vietnamese Mekong River Delta

Three radiocarbon-dated sediment cores from the northeastern Vietnamese Mekong River Delta have been analysed with a multiproxy approach (grain size, pollen and spores, macro-charcoal, carbon content) to unravel the palaeoenvironmental history of the region since the mid Holocene. During the mid-Holocene sea-level highstand a diverse, zoned and widespread mangrove belt (dominated by Rhizophora) covered the extended tidal flats. The subsequent regression and coeval delta progradation led to the rapid development of a back-mangrove community dominated by Ceriops and Bruguiera but also represented locally by e.g. Kandelia, Excoecaria and Phoenix. Along rivers this community seems to have endured even when the adjoining floodplain had already shifted to freshwater vegetation. Generally this freshwater vegetation has a strong swamp signature but locally Arecaceae, Fabaceae, Moraceae/Urticaceae and Myrsinaceae are important and mirror the geomorphological diversity of the delta plain. The macro-charcoal record implies that natural burning of vegetation occurred throughout the records, however, the occurrence of the highest amounts of macro-charcoal particles is linked with modern human activity.

Pollen records of profile Krumbach from southern Germany

Some years ago a fossil lake basin was found in the northeastern part of the former Rhine-pied- mont-glacier, situated between the endmoraine system ofthe elassical Riß- andWürm glacia- tions, respectively. The lacustrine sediments contain the pollenflora ofthe Eemian interglacial. They are intensively thrusted. These sediments are eovered by a loam-layer, rieh in elasts. The thickness of this loam-layer varies between at least 170 and 400 cm. It consists in its major part of loess-loam and solifluction material. Yet just on top of the lake sediments mentioned an in- tensively compressed loam, characterized by quarzgrains with all features of glacially pressed material, together with striated elasts is met with. It strongly resembles atil!. Ifthis is true, the stratigraphie division ofthe last glaciation strongly deviates from the hitherto accepted scheme, incorporating an early glacier advance, long before the elassical young-endmoraine systems of the Würm glaciation were formed.

Biostratigraphical investigations of Lago d'Averno, near Naples

Remains of diatoms, molluscs, ostracods, foraminifera and pollen exines preserved in the sediments of Lago d'Averno, a volcanic lake in the Phlegrean Fields west of Naples, allowed us to reconstruct the changes in the ecological conditions of the lake and of the vegetation around it for the period from 800 BC to 800 AD. Lago d'Averno was at first a freshwater lake, temporarily influenced by volcanic springs. Salinity increased slowly during Greek times as a result of subsidence of the surrounding land. Saline conditions developed only after the lake was connected with the sea by a canal, when Portus Julius was built in 37 BC. The first post-Roman period of uplift ended with a short freshwater phase during the 7th century after Christ. Deciduous oakwoods around the lake was transformed into a forest of evergreen oaks in Greek times and thrived there - apparently almost uninfluenced by man - until it was felled, when the Avernus was incorporated into the new Roman harbour in 37 BC, to construct a shipyard and other military buildings there. Land-use was never more intense than during Roman times and weakest in Greek and Early Roman times, when the Avernus was considered a holy place, the entrance to the underworld.

Composition of the argillite sequence, continental slope of the Sea of Japan

The argillite sequence located at the base of the sedimentary cover on the continental slope of the Sea of Japan was studied by petrographic, palynological, and X-ray diffraction methods. Two spores-pollen complexes were distinguished in it: the Late Oligocene reflecting cooling and the Early Miocene corresponding to initiated warming. Data obtained indicate that the sequence is composed of terrigenous silty-clayey sediments that accumulated in shallow coastal-marine settings. The global sea-level rise at the Early-Middle Miocene transition, combined with regional tectonic processes, determined basin's deepening, owing to which the argillite sequence was overlain by a thick layer of Middle Miocene diatomaceous-clayey sediments. Due to tectonic movement along existing faults in the terminal Late Miocene, the argillite sequence occurring initially at depths of at least 400-500 m was locally exhumed to the basin bottom.