Chronostratigraphy and ecology of two Middle and Upper Pleistocene sites (Jersey,Channel Islands)

Thanks to their coastal location on what is now an island on the continental shelf, the two early Middle Palaeolithic sites of La Cotte à la Chèvre and La Cotte de St Brelade are especially sensitive to environmental change. The former is a small sea-cave cut during a +18 m marine transgression. At the latter site no traces of this episode have been found, but the archaeologically very rich sediments of Saalian age were sculpted into a cliff during the +8 m transgression of isotope substage 5e, and were capped by a triple soil followed by thick Weichsehan deposits ; an earlier interglacial complex is dated to 238 ±35 ky, and must be attributed to oxygen isotope stage 7. Geology, flora and fauna combine to document a long sequence of environmental change. The deep ravine system is a natural sediment trap in which wind-transported materials – chiefly loess, and sand formed by decay of the granite bedrock – alternated in a manner clearly linked to climatic change. The occupation of the two sites appears to cover much the same chronological range. They may be regarded as complementary, in that if they were used by a single human group La Cotte à la Chèvre would have provided a convenient means of slightly extending the catchment of the much larger and better placed St Brelade site, which on archaeological evidence was a far more important focus of activity. Human presence in the area was controlled directly or indirectly by climate ; there appears to have been a ‘window’ within which the sea-level was low enough to permit easy access to Jersey while the cold was not severe as to inhibit activity altogether. The landscape would have varied from, at one extreme, a comparatively wooded peninsula attached to the Cotentin, to a tableland set in a broad coastal plain with more open vegetation. Perhaps the most remarkable aspect of Pleistocene Jersey is the clarity with which the close mutual interdependence between different components is revealed – climate, sedimentation and soil formation, sea-level changes and manne erosion, physical geography, fauna and flora, human presence and economy, supplies of raw material for tool-making and stoneworking techniques.