Abstract. Eine revidierte Vergletscherungsgeschichte des nördlichen Vorlandes der Schweizer Alpen wird vorgestellt, basierend auf Feldbefunden und chronologischen Daten von verschiedenen Schlüssellokalitäten und Regionen. Die ältesten quartären Sedimente der Schweiz sind mehrphasige Kiese, in die Till und Hochflutsedimente eingeschaltet sind (’Deckenschotter’). Bedeutende Unterschiede im Basisniveau der Schotterablagerungen erlauben die Unterscheidung zweier komplex augebauter Einheiten (’Höhere Deckenschotter’, ’Tiefere Deckenschotter’), die durch eine Phase bedeutender Einschneidung getrennt sind. Säugetierreste stellen die ältere Einheit (‘Höhere Deckenschotter’) in die Zone MN 17 (2.6–1.8 Ma). Jeder der Komplexe enthält Belege für zumindest zwei, möglicherweise sogar bis zu vier eigenständige Eiszeiten, woraus sich in Summe bis zu acht frühpleistozäne Vergletscherungen des Schweizer Alpenvorlands ergeben. Die frühpleistozänen Deckenschotter sind von mittelpleistozänen Ablagerungen durch eine Zeit bedeutender Erosion getrennt, die wahrscheinlich durch tektonische Bewegungen und/oder eine Umleitung des Alpenrheins verursacht wurde (Mittelpleistozäne Reorganisation – MPR). Das Mittel-/Spätpleistozän beinhaltet vier oder fünf Eiszeiten, die nach ihren Schlüsselregionen als Möhlin-, Habsburg-, Hagenholz- (unsicher, unzureichend belegt), Beringen- und Birrfeld-Eiszeit benannt sind. Die Möhlin-Eiszeit repräsentiert die grösste Vergletscherung des Schweizer Alpenvorlandes, während die Beringen-Eiszeit von nur wenig geringerer Ausdehnung war. Der letzte Glazialzyklus (Birrfeld-Eiszeit) umfasst wahrscheinlich drei eigenständige Gletschervorstösse, die auf ca. 105 ka, 65 ka und 25 ka datiert wurden. Für den letzten Eisvorstoss wird eine detaillierte Radiokohlenstoffchronologie für den Eisaufbau und das Abschmelzen präsentiert.

Different pathotypes existing in the field isolate ‘e’ of Plasmodiophora brassicae were separated by repeated propagation in resistant host plants or by inoculation with single spores. The resulting isolates were studied by combining the molecular markers of fingerprint‐like patterns and characterization of pathogenic capacity using genetically homogenous Arabidopsis ecotypes under controlled environmental conditions, so that the selection of virulent pathotypes within resistant host plants could be demonstrated. These host‐selected isolates shared the molecular and phytopathological characters of corresponding single‐spore isolates.

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Abstract. 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.

The sedimentary infills of subglacially eroded bedrock troughs in the Alps are underexplored archives for the timing, extent and character of Pleistocene glaciations but may contain excellent records of the Quaternary landscape evolution over several glacial–interglacial cycles. The onset of sedimentation in these bedrock troughs is often reflected by diamicts and gravels directly overlying bedrock in the deepest basin segments. Subglacial or proglacial depositional environments have been proposed for these coarse‐grained basal units but their characteristics and origin remain controversial. This article presents results from drill cores that recovered a coarse‐grained basal unit in a major buried bedrock‐trough system in the Lower Glatt Valley, northern Switzerland. The excellent core recovery allowed a detailed study combining macroscopic, microscopic and geochemical methods and gives unprecedented insights into the transition from erosion to deposition in overdeepened bedrock troughs. These results show that the basal infill comprises diamicts, interpreted as subglacial tills, separated by thin sorted interbeds, originating from subglacial cavity deposition. The stacking of these units is interpreted to represent repeated switching between a coupled and decoupled ice–bed‐interface indicating an ever‐transforming mosaic of subglacial bed conditions. Decoupling in response to high basal water pressures is probably promoted by the confined subglacial hydraulic conditions resulting from the bedrock acting as aquitards, the narrow reverse sloping outlet and a large catchment area. While stratigraphic and lithological evidence suggests that erosion and the onset of basal sedimentation occurred during the same glaciation, different scenarios for the relative timing of infilling in relation to formation and glaciation of the bedrock trough are discussed. Overlying deltaic and glaciolacustrine sediments suggest deposition during subsequent deglaciation of the bedrock trough. The basal sediment characteristics are in agreement with previous reports in hydrogeological and seismic exploration and suggest the occurrence of similar basal successions in other subglacially overdeepened basins in the Alps and elsewhere.