Combining geology and archaeology for an unprecedented improvement in the knowledge of Quaternary environments and Palaeolithic record: a northern France perspective

The approach combining geology and archaeology was initiated in the Somme valley in northern France at the end of the 19th century by pioneers of Palaeolithic research such as J. Boucher de Perthes (1860). Later, still in this area, the study of Quaternary sequences and palaeoenvironments was marked by the development of the first multidisciplinary studies integrating data from molluscs, micromammals, pollen and the first radiocarbon dates in the 1970s. Finally, over the last thirty years, the geoarchaeological approach has undergone an unprecedented development supported by i) the rapid development of rescue archaeology and ii) the refinement of tools such as geochronology (ESR on quartz, TL & OSL, geophysics, isotopic geology, etc.). Today, Northern France can be considered a major reference "laboratory" for geoarchaeological approaches and Quaternary research. In this area, recent work involving thousands of test pits (up to 8-10 m deep) and large archaeological excavations (> 2 000 m²) has led to a real leap forward in our knowledge of loess-palaeosols records, fluvial terrace sequences and valley-bottom fluvial environments. This provides a robust database for studying the interactions between Palaeolithic occupation and palaeoclimatic and palaeoenvironmental change. The presentation will draw on some 30 years of fieldwork in the area, including early experience of 'rescue' archaeology such as the Channel Tunnel for high-speed rail lines. The new results to be summarised here will concern both loess-palaeosols records and fluvial sequences from the Somme terrace system. For the loess-palaeosols sequences, the last interglacial-glacial cycle that is the best preserved and widespread over the whole area, provides a detailed and robust reference stratigraphic framework with about 40 individual units detected over the whole area. With regard to the Pleistocene fluvial record and associated Palaeolithic sites, the outcome of preventive archaeological work is less important as terrace deposits are by nature more localised and therefore not often affected by rescue excavations. However, during the last 20 years two major discoveries have been made in fluvial sequences: i) in the high terrace of the Somme River at Abbeville with the rediscovery of the Moulin Quignon site now dated at about 650 ka and exhibiting the oldest evidence of Acheulean in western Europe and ii) the Eemian tufa sequence and Middle Palaeolithic site of Caours (± 123 ka) which has completely changed our perception of Neanderthal occupation of western Europe during temperate periods. In the future, the approach will be extended in the context of the Canal Seine North-Europe project*, which will cross the entire loess area of northern France and where major Palaeolithic excavations have already begun in January 2025.

 

* https://www.canal-seine-nord-europe.fr/en/the-channel-map/