Climatic patterns in other southwestern French sites

No other site in southwestern France has produced a climatic and environmental sequence for the earlier stages of the Upper Pleistocene which can compare either in length and completeness, or in the level of detail and resolution, with that recorded at Combe Grenal. There are, however, a number of sites which can be used either to corroborate and reinforce the general climatic implications of the Combe Grenal sequence or to add some new elements to the final stages of the climatic sequence which are not well represented in the Combe Grenal deposits. The two main sites in this connection are Pech de l'Aze II, located close to the small valley of the Enea only 6 km to the north of Combe Grenal, and the lower shelter at Le Moustier located in the Vezere valley, some 22km to the north-west (see Fig. 8.1). The importance of these sites is that they have both been dated recently by a long and internally coherent series of absolute dates, which can be used to provide direct control over the correlation of the climatic and environmental sequences with the more general climatic sequences recorded in deep-sea cores (Valla-das et al. 1986; Grün et ah 1991; Meilars & Grün 1991).

The sequence recorded at Pech de YAze site II (summarized in Figs 2.24-2.26) can be described briefly, since this appears to provide in most respects a close parallel for the climatic, vegetational and faunal sequence documented in the earlier part of the last-glacial sequence at Combe Grenal (Bordes 1971a, 1972; Laville 1975; Laville et al. 1980; Paquereau 1969; Bordes & Prat 1965; Grün et al. 1991). The major interstadial episode rep resented in layers 4A-4C (characterized by overall arboreal pollen ratios of around 50-60 percent and including many warmth-demanding deciduous tree species: Fig. 2.24) is almost certainly the equivalent of the similar warm episode reflected in levels 43-41 at Combe Grenal and has been dated by electron-spin-resonance (ESR) measurements on associated animal teeth to around 70-85,000 BP (Fig. 2.26) - i.e. clearly coinciding with isotope stage 5a (Grün et al. 1991). The subsequent, much less marked, climatic ameliorations in levels 2G' and 2G most probably correlate with the similar milder intervals recorded in layer 38 and between layers 35 and 36 at Combe Grenal. After this point the entire character of the sedimentary, pollen and faunal sequence reflects a sharp transition to much colder and apparently much drier conditions, clearly coinciding with the climatic transition from isotope stages 5a to 4. The ESR dates for these upper levels centre on ca 60-70,000 BP, although with a degree of dispersal in the individual measurements which could cover almost any period from the beginning of isotope stage 4 to the earlier part of stage 3 (Fig. 2.26). Perhaps the most striking aspect of this climatic sequence is reflected in the associated faunal assemblages (Bordes & Prat 1965; Laquay 1981). As at Combe Grenal, the lower part of the last-glacial sequence (layers 4E-2G) is marked by a heavy predominance of red deer and other temperate species such as wild pig, roe deer and aurochs, with only very sporadic remains of reindeer. Reindeer first appear clearly in level 4A2 and rise rapidly to dominance in the upper part of layer 2, apparently associated with the early glacial maximum of isotope stage 4 (Fig. 2.25). The entire sequence at Pech de l'Aze II therefore provides in most respects a close parallel for that documented in the lower and middle parts of the Combe Grenal sequence. The Pech de l'Aze II sequence is particularly important in confirming the overall chronology proposed for this part of the climatic succession at

Figure 2.24 Pollen sequence through the earlier last-glacial deposits (layers 2-4) at Pech de VAze II, after Paquereau 1969. The proposed chronology for the sequence is indicated in Fig. 2.25.

Reindeer %

Isotope stage Arboreal pollen % correlation

Reindeer %

Isotope stage Arboreal pollen % correlation

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