Abstract
There are no Saalian Stage pollen records in Northwest Europe that not only cover an entire interglacial complex but also have been successfully correlated down to marine isotope substage level. The presented pollen record fills this knowledge gap. Three pollen sequences, sampled from a well-preserved Saalian Stage river terrace near Brussels (Belgium), together span most of an interglacial complex: two interglacial cycles and one interstadial separated by colder intervals. To date the pollen data, the authors present a multi-proxy supported river evolution model through which the correlation of the pollen record with the penultimate interglacial complex (Marine Isotope Stage (MIS) 7) becomes apparent. The authors further illustrate homotaxis—defined as the similarity between pollen diagrams that are not necessarily contemporaneous—by comparing MIS 7 with MIS 5 pollen data from the same area, convincingly curve-match the pollen record with marine isotope data, and point to similarities between Southern and Northwest European vegetation dynamics and climate variability during MIS 7.
| Original language | English |
|---|---|
| Article number | 108113 |
| Pages (from-to) | 1-16 |
| Number of pages | 16 |
| Journal | Quaternary Science Reviews |
| Volume | 310 |
| Early online date | 16 May 2023 |
| DOIs | |
| Publication status | Published - 15 Jun 2023 |
Bibliographical note
Funding Information:Although Ips I & II (Fig. 3) resemble a typical Eemian vegetational development—similar tree taxa, especially Carpinus—the arrival of oak during a pre-temperate phase distinguishes Ips II from the Eemian (de Jong, 1988) in the Low Countries. Also Ips I cannot be correlated with the Eemian, because a succession of two interglacial cycles (Ips I & II) during the Last Interglacial complex (MIS 5) has never been observed in the Low Countries (Cleveringa et al., 2000; De Moor et al., 1978; Kasse et al., 2022; Zagwijn, 1961). The presence of 13 Fagus pollen grains in IPS (Fig. 3) and 1 in RAM (Fig. 4) supports this hypothesis: an inventory of Eemian terrestrial pollen sites nearby (1–40, blue dots, Fig. 6) yielded none in a total of 713 spectra (App. F). The presence of Fagus thus excludes either Ips I or II to be Eemian. Palaeobotany (Fagus) and malacology (C. fluminalis), in combination with archaeology (Levallois technology), therefore exclude that meandering river activity during the Last Interglacial complex (MIS 5) resulted in Units 2–3. Instead, the combination of proxies allows to correlate Units 2–3 with MIS 7.Units 4–5 represent braided river deposits bound to the southwest by a MIS 7 meandering channel belt (Units 2–3) and to the northeast by a similar single thread system from the last interglacial complex (Units 7–10) (Fig. 2). Units 4–5 are therefore younger than MIS 7 and older than MIS 5, and hence date from MIS 6 (191–130 ka, Lisiecki and Raymo, 2005): a conclusion supported by Lister and Sher (2001) and the just-mentioned ESR age estimates (see Units 7–10). The paleosol that developed in the lag deposit (Unit 6, Fig. 2) is correlated with the Eemian Rocourt soil (Gullentops, 1954; Gullentops et al., 2001). The top of Unit 6 indicates the ground level during the Eemian, about 5 m lower than current topography.In Table 2, we correlate forest phases recorded in Southern European pollen sequences and IRN with MIS 7 stratigraphy. Lake Kopais is our reinterpretation of the original based on a correlation with the Ioannina-284 and Tenaghi Philippon pollen sequences. We consider the combination of two oak forest phases (KP 5 & 7) separated by a grassland dominated interval (KP 6), below the Eemian zone KP 9a, to represent MIS 7 in Lake Kopais. The colder MIS 7b interval (see Section 5.5) is not reflected in the Lake Kopais pollen diagram during zone KP 7 and barely noticeable in the Ioannina-284 AP curve (zone G-3a). In the latter, the distinction between the Zitsa II (MIS 7a) and Zitsa III (MIS 7c) forest phases could only be made because of the expansion in the lowland and mountains around Lake Ioannina of late temperate tree taxa (Carpinus, Abies and Fagus) that induce a double peak of Quercus. Hornbeam, fir and beech were absent during MIS 7 in the oak-dominated lowland surrounding Lake Kopais. In the Tenaghi Philippon sequence, palynologists counted only 7 spectra (24 cm interval) with AP values < 50% between 198.82 and 200.7 ka (MIS 7b), which could easily be overlooked with the 60 cm sampling resolution of Lake Kopais (Table 2). We further support the propositions of Reille et al. (1998; contra Tzedakis et al., 1997) and Desprat et al. (2006) to correlate, respectively, only the first part of Roma III (VdC-7a, Valle di Castiglione) and the second part of zone H2 Symvolon (Tenaghi Philippon) with MIS 7a (Table 2).
Publisher Copyright:
© 2023 Elsevier Ltd
Funding
Although Ips I & II (Fig. 3) resemble a typical Eemian vegetational development—similar tree taxa, especially Carpinus—the arrival of oak during a pre-temperate phase distinguishes Ips II from the Eemian (de Jong, 1988) in the Low Countries. Also Ips I cannot be correlated with the Eemian, because a succession of two interglacial cycles (Ips I & II) during the Last Interglacial complex (MIS 5) has never been observed in the Low Countries (Cleveringa et al., 2000; De Moor et al., 1978; Kasse et al., 2022; Zagwijn, 1961). The presence of 13 Fagus pollen grains in IPS (Fig. 3) and 1 in RAM (Fig. 4) supports this hypothesis: an inventory of Eemian terrestrial pollen sites nearby (1–40, blue dots, Fig. 6) yielded none in a total of 713 spectra (App. F). The presence of Fagus thus excludes either Ips I or II to be Eemian. Palaeobotany (Fagus) and malacology (C. fluminalis), in combination with archaeology (Levallois technology), therefore exclude that meandering river activity during the Last Interglacial complex (MIS 5) resulted in Units 2–3. Instead, the combination of proxies allows to correlate Units 2–3 with MIS 7.Units 4–5 represent braided river deposits bound to the southwest by a MIS 7 meandering channel belt (Units 2–3) and to the northeast by a similar single thread system from the last interglacial complex (Units 7–10) (Fig. 2). Units 4–5 are therefore younger than MIS 7 and older than MIS 5, and hence date from MIS 6 (191–130 ka, Lisiecki and Raymo, 2005): a conclusion supported by Lister and Sher (2001) and the just-mentioned ESR age estimates (see Units 7–10). The paleosol that developed in the lag deposit (Unit 6, Fig. 2) is correlated with the Eemian Rocourt soil (Gullentops, 1954; Gullentops et al., 2001). The top of Unit 6 indicates the ground level during the Eemian, about 5 m lower than current topography.In Table 2, we correlate forest phases recorded in Southern European pollen sequences and IRN with MIS 7 stratigraphy. Lake Kopais is our reinterpretation of the original based on a correlation with the Ioannina-284 and Tenaghi Philippon pollen sequences. We consider the combination of two oak forest phases (KP 5 & 7) separated by a grassland dominated interval (KP 6), below the Eemian zone KP 9a, to represent MIS 7 in Lake Kopais. The colder MIS 7b interval (see Section 5.5) is not reflected in the Lake Kopais pollen diagram during zone KP 7 and barely noticeable in the Ioannina-284 AP curve (zone G-3a). In the latter, the distinction between the Zitsa II (MIS 7a) and Zitsa III (MIS 7c) forest phases could only be made because of the expansion in the lowland and mountains around Lake Ioannina of late temperate tree taxa (Carpinus, Abies and Fagus) that induce a double peak of Quercus. Hornbeam, fir and beech were absent during MIS 7 in the oak-dominated lowland surrounding Lake Kopais. In the Tenaghi Philippon sequence, palynologists counted only 7 spectra (24 cm interval) with AP values < 50% between 198.82 and 200.7 ka (MIS 7b), which could easily be overlooked with the 60 cm sampling resolution of Lake Kopais (Table 2). We further support the propositions of Reille et al. (1998; contra Tzedakis et al., 1997) and Desprat et al. (2006) to correlate, respectively, only the first part of Roma III (VdC-7a, Valle di Castiglione) and the second part of zone H2 Symvolon (Tenaghi Philippon) with MIS 7a (Table 2).
Keywords
- late Middle Pleistocene
- Northwest Europe
- Paleoclimatology
- Palynology
