Early and Middle Pleistocene pollen assemblages of deep core drillings in the northern Upper Rhine Graben, Germany

Abstract

Recent core drillings, carried out during water-economic exploration in the area of Mannheim/Ludwigshafen/Schifferstadt (Rhine-Neckar region, Germany), have produced a more differentiated stratigraphic division of the Pleistocene sediments of the northern Upper Rhine Graben. Pollen analytical investigations as well as malacological, heavy mineral, palaeomagnetic and lithological research have led to a stratigraphic reinterpretation of the gravel layers and intermediate horizons. Based on the results of the pollen analyses, the Mannheim interglacial period in the upper intermediate horizon (Oberer Zwischenhorizont, OZH) cannot be assigned to the Eemian as stated earlier. The occurrence of Fagus, Celtis and Azolla, along with the results of malacological analyses, indicate a Cromerian age for the Mannheim Interglacial. In addition, a pollen sequence from a different interglacial in the core sediments from Schifferstadt could also be assigned to the Cromerian. The Schifferstadt Interglacial is divided into a lower optimum phase with high values of Ulmus, Quercus and Corylus while Carpinus is completely absent, and an upper optimum phase with low values of Carpinus. Fagus is absent in the whole sequence. The OZH comprises not only the two interglacial pollen sequences described above but also parts of at least four Middle Pleistocene Interglacials. In the lower part of the drillings in Schifferstadt and Ludwigshafen, which are assigned to the Early Pleistocene, pollen assemblages with Fagus are likely to correlate with parts of the Tiglian A substage. There is a clear change to a Tertiary type of pollen flora at 91 m at Schifferstadt and at 186 m in Ludwigshafen.

Infrared radiofluorescence (IR-RF) dating of middle pleistocene fluvial archives of the Heidelberg Basin (Southwest Germany)

“…Following pollen contents a Cromerian age (older than OIS 15 if following Fig. 7) of the Upper Interlayer could be assumed as it contains pollen markers from different interglacials (Knipping, 2008) and also the found mollusc fauna (Rähle, 2005;Wedel, 2008) would agree with this interpretation.…”

“…Knipping (2008) investigated pollen assemblages from this layer, and concluded that this layer cannot be correlated with the Eemian interglacial. Following the pollen contents as well as the molluscs identification (Rähle, 2005;Wedel, 2008), a Cromerian age was suggested for the Upper Interlayer.…”

“…Based on the IR-RF ages we now can assume a deposition during an early Saalian stage for this layer. This means that there is a discrepancy between the interpretation of the available biostratigraphical information based on pollen and molluscs (Rähle, 2005;Knipping, 2008;Weidenfeller and Knipping, 2008;Wedel, 2008) and the IR-RF age estimates. Following pollen contents a Cromerian age (older than OIS 15 if following Fig.…”

Macaques at the margins: the biogeography and extinction of Macaca sylvanus in Europe

“…Fir pollen has also been recovered from Hoxne although its stratigraphic position is not clear (Ashton et al, 2008 The plant species at any given location obviously fluctuated according to glacial cyclicity in the Pleistocene. This is evident, for example, in well-studied Middle Pleistocene deposits of the Upper Rhine Valley where pollen spectra indicate late-glacial flora such as juniper and birch giving way to an interglacial sequence that includes oak and elm, with pine, spruce, beech and other genera now known only from south east Asia sampled elsewhere in the sequence (Knipping, 2008). The plasticity evident in modern M. sylvanus (Menard, 2002) indicates that past conspecifics would have been ideally placed to 'ride out' at least the initial vegetation changes that occurred during the transition from interglacial to glacial conditions before dying out or retreating to refugia, and may have been able to move back into previous occupation areas quite rapidly with glacial retreat.…”

A consistent magnetic polarity stratigraphy of late Neogene to Quaternary fluvial sediments from the Heidelberg Basin (Germany): A new time frame for the Plio–Pleistocene palaeoclimatic evolution of the Rhine Basin

“…The descriptions and analyses of core P36 are as yet undisclosed. Until now, only studies of the older sister cores P34 and P35 have been published, e.g., Rolf et al (2008), Weidenfeller and Knipping (2008), and Knipping (2008).…”