ALBERT

Description: LOŽEK (1986) is of the opinion that Pupilla loessica has been found recently in Central Asia. The aim of this study is to provide some initial, concrete contributions to the discussion of this subject. It should be understood as a basis for further investigations. During recent visits on site between 1995 and 2006 in Central Asia in the Russian Altay, in Northern Mongolia, in the Baikal region and in the Tien Shan, numerous recent malacocenoses were examined. In many places evidence was found of a form of Pupilla which had not previously been described from this region; its shell morphology cannot be distinguished from Pupilla loessica. Its distribution is concentrated in the strongly continental Khrebet Saylyugem in the South Eastern Altay. The probability of the occurrence of Pupilla loessica in Central Asia is supported, apart from the shell morphology criteria, by the preference of this species for more continental types of habitat with average annual temperatures markedly below 0° C and the corresponding accompanying fauna adapted to the cold, including e.g. Columella columella, Vertigo genesii, Vallonia tenuilabris, etc., which make these fauna easily comparable to the Pleistocene glacial associations of the Central European region.

Description: Middle and Upper Quaternary volcanic events are often difficult to date, in particular when minerals suitable for 40Ar/39Ar-dating are missing. Here, we present first tests of a newly developed technique to use the thermoluminescence (TL) of maar tephra and crustal xenoliths for dating the eruption event. We take into consideration that resetting of the latent geological TL of country rock fragments during eruption may be incomplete. We therefore develop the “partial heat – longest plateau” (PHLP) technique to approach the inherited TL signal at eruption. This technique can overcome TL age overestimates due to incomplete zeroing, as is demonstrated for some eruptions in the Quaternary Eifel Volcanic Field, Germany, in the time range from 11 to 300 ka old. Although we avoid the often observed strong anomalous fading of volcanic feldspars and other volcanic minerals by using heated country rock xenoliths, we still face the problem of longer-term anomalous fading which may be responsible for apparent age underestimates. The orange-red TL emissions (RTL) of pure fine-grained quartz extracts from crustal xenoliths are also tested from two samples. This approach needs, however, further systematic investigations into the TL characteristics of RTL.

Description: The stratigraphy and paleogeography of the Deckenschotter (“cover gravels”) of the Rhine glacier system between Lake Constance, the city of Schaffhausen and the Klettgau area (Switzerland, Germany) was revised. This was achieved by means of new surveying and mapping, petrographical analysis und a systematic evaluation of available literature and borehole data. Within the Deckenschotter three morphostratigraphic units can be discerned: (a) Höhere (higher) Deckenschotter, (b) Tiefere (lower) Deckenschotter and (c) Tiefere Deckenschotter, unteres Niveau (lower level). The topographically highest unit, the Höhere Deckenschotter, cannot be subdivided into lithostratigrafic units. The gravels classified as Tiefere Deckenschotter are grouped into two morphostratigraphical units; the altitude difference of the bases of both units is minor. They are, however, separated by an erosional discontinuity caused by a signifi cant rearrangement of the hydrographic network.The older one of the two units (Tiefere Deckenschotter) comprises sediments of at least two depositional phases, separated from each other by a hiatus. There are signs of temperate climatic conditions during the period of non-deposition. The tectonic analysis of the study area showed that in general the altitude of the Deckenschotter was not affected by post-depositional tectonic activity. A tectonic displacement of the Deckenschotter occurrences in the Hegau cannot be ruled out as their topographic position is unusually high compared to equivalent deposits further paleo-downstream. However, this does not affect the proposed morphostratigraphic subdivision. The Upper Rhine Graben system (tectonic lowering) controlled the hydraulic base level and the morphogenesis for both the Deckenschotter occurrences discussed here and those in central northern Switzerland. Therefore, the morphostratigraphic units of both regions can be correlated, even though the number of lithostratigraphic units does not match. In the Höhere Deckenschotter this could be ascribed to an incomplete sedimentary record or a lack of data; on the other hand, this might indicate that the connection Lake Constance – Upper Rhine Graben was established later than the connection Lake Walen – Upper Rhine Graben. In contrast, there is no simple morpho- or lithostratigrafic correlation with the early pleistocene deposits of the German Alpine Foreland, since they are oriented towards and controlled by the Donau river system.

Description: Ground temperature measurements have been carried out at eleven different sites of the Prokhodnaja valley in the high mountains of the Zailijskij Alatau (Northern Tian Shan, Kazakhstan) between the summers of 2003 and 2004. For this purpose the periglacial zone and adjacent altitudinal zones have been examined between 2,500 and 4,000 m asl with an equidistance of 250 m. The influences of the altitude, the exposure as well as the depth below the earth’s surface on the thermal content and condition of periglacial soils have been considered. The measurements provide useful information about the relations between quantity and quality of freeze-thaw action and the parameters mentioned above.

Description: The method of surface exposure dating using in-situ produced cosmogenic nuclides has become an important and widely applied tool in Quaternary science. One application is the dating of erratic boulders on moraines. An important problem however remains: the evaluation of potential pre-exposure time for samples from boulder surfaces. We have tested pre-exposure by sampling all sides of a recently exposed boulder in order to measure inherited nuclides from prior exposure periods. The sampled erratic boulder rests on the right lateral moraine of the most recent advance of the Glacier de Tsijiore Nouve in the Arolla Valley, Switzerland. Mapping of the area was done to reconstruct the Holocene fluctuations of the glacier. This glacier is especially useful for such a test as it is characterized by an ideal geometric relationship between accumulation and ablation area and, therefore, responds rapidly to mass-balance changes. The sampled boulder was deposited in 1991. Assuming no prior exposure the expected concentration of a given cosmogenic nuclide should be near zero. The 10Be/9Be ratios of the five measured samples were indistinguishable from blank values within the given errors, demonstrating that the samples did not experience pre-exposure. Three samples measured for 21Ne reveal 21Ne/20Ne and 22Ne/20Ne ratios similar to those of air, with no detectable prior cosmogenic Ne accumulation.

Description: The Holocene flood plain of the River Rhine is a complex dynamic sedimentary system. A series of geochronological results for the Bremgarten section including optically stimulated luminescence (OSL) and radiocarbon dating was determined to improve the understanding of part of the Holocene evolution of the River Rhine. The applied single aliquot regenerative (SAR) protocols and the applied experimental studies to find the best luminescence behaviour leave us with confidence that OSL dating is a suitable method for dating fluvial sediments from large river systems. Insufficient bleaching of the sediments from Bremgarten prior to deposition seems to be not as dramatic as previously thought. OSL and radiocarbon dating results give evidence for a short period of major erosion and re-sedimentation of fluvial sediments from the “Tiefgestade” at the Bremgarten section between 500 and 600 years before present. This time period correlates with the beginning of the Little Ice Age at about AD 1450. Several severe floods occurred in Southern Germany between AD 1500 and 1750; all those floods correlate to the period of the Little Ice Age, including the destruction of the village of Neuenburg AD 1525.

Description: A description and classification of the successions of the new scientific core drillings at Heidelberg is presented. Since 2002 drilling and research activities were ongoing in the Heidelberg Basin (HDB), as a mid-continental sedimentary archive within the Upper Rhine Graben (URG), Germany. The HDB is supposed to host one of the longest continuous successions of Quaternary sediments in Europe, due to continuous subsidence of the basin and sediment input from various sources. The HDB is about half-way between the Alpine source area of the Rhine and the North Sea. Here the Quaternary input is least affected by discontinuities due to climate events as alpine glacier meltdown events or periods of low sea level. Reversely, the low influence of climate leads to a larger tectonic control. The sedimentary succession of more than 500 m is considered as primarily controlled by tectonics, but with incorporated climate signals. For classification purposes, sediment provenance, lithofacies-associations, and the ratio of accommodation space and sediment input are used. Some biostratigraphic markers are also available. We suggest a sedimentary scenario where the overall fluvial environment is twice interrupted by lacustrine intervals. The accommodation space varies too: in one period it expands even beyond the eastern boundary fault of the HDB.

Description: A pollen record from the borehole Heidelberg UniNord, in the northern Upper Rhine Graben shows evidence for one of the rare Waalian thermomers. The record may not comprise the complete thermomer it certainly reflects a sort of succession, initiated by sequences with high values of pine and spruce, followed by a dominance of pine, hemlock-spruce and spruce and finished by a dominance of hemlockspruce, oak and hornbeam becomes visible. Pollen percentage values for Tsuga reach 20 % indicating that this taxon is an important forest element. There is a continuous presence of Carya, Pterocarya, Eucommia, Celtis and Ostrya-type. Neighbouring pollen records reveal similar patterns. The pollen diagram is closely related with the Waalian profiles Leerdam and Eindhoven from the Netherlands.

Description: Currently, the Heidelberg Basin is under investigation by new cored research boreholes to enhance the understanding concerning the control on Pliocene and Quaternary sedimentation by (neo)tectonics and climate. The Heidelberg Basin is expected to serve as a key location for an improved correlation of parameters that characterise the climate evolution in North Europe and the Alpine region. The recovery of sediment successions of high temporal resolution that are complete with respect to the deposition of Pleistocene glacials and interglacials in superposition is of special importance. Prior to the new research boreholes in Viernheim and Heidelberg geophysical pre-site surveys were performed to identify borehole locations that best achieve these requirements. In the area of the Heidelberg Basin the strongest negative gravity anomaly of the entire Upper Rhine Graben is observed (apart from the Alps), hinting at anomalously thick sediment deposits. However, especially reflection seismic profiles contributed significantly to the decision about the borehole locations. In the city of Heidelberg for the first time, the depocentre of the Heidelberg Basin, as indicated by additional subsidence compared to its surroundings, was mapped. In this area, sediments dip towards the eastern margin of the Upper Rhine Graben. This is interpreted to represent a rollover structure related to the maximum subsidence of the Upper Rhine Graben in this region. At the Viernheim borehole location the seismic survey revealed several faults. Although these faults are mainly restricted to depths greater than 225 m, the borehole location was fi nally adjusted with respect to this information.

Description: Cores from several boreholes in the Ludwigshafen area were analysed to investigate their sedimentology, palynology, palaeomagnetics, rock magnetics and heavy mineral composition. The preliminary results are presented from the new Ludwigshafen-Parkinsel borehole P35, which was drilled 500 m WSW of borehole P34, to a total depth of 300 m. Correlation between the two boreholes reveals similarities and dissimilarities in stratigraphy, structure and the thickness of the sediments. As a result of core documentation and the preliminary evaluation of the investigation results, a good correlation is established between the coarse and fi ne-grained sequences in both boreholes down to a depth of 122 m. However, the Plio-Pleistocene boundary in borehole P35 is much deeper than in P34. A fault throw of 42 m is assumed, attributable to young tectonics. The poor correlation between the thicknesses of the sediments in the lower sections of the two boreholes suggests that tectonism was particularly active in the Pliocene and Lower Pleistocene. The different occurrence of interglacial sequences in the two Ludwigshafen boreholes can be attributed to fl uvial dynamics and neotectonic events. Further palynological analysis is required to determine whether the alternation of at least fi ve interglacial periods determined in the Ludwigshafen-Parkinsel P34 borehole, can also be confi rmed in the P35 borehole. The information gained so far from the correlation of the already analysed Middle Pleistocene interglacials in the Ludwigshafen/Mannheim area, as well as the links with the primarily Lower Pleistocene sections in Schifferstadt, already suggest that this would allow a much better understanding of the changes in vegetation and climate during the Pleistocene.