CLIMATIC CONDITIONS IN THE EEMIAN INTERGLACIAL RECORDED BY STABLE ISOTOPES FROM A NEUMARK-NORD LIMNIC SEDIMENT SEQUENCE (CENTRAL GERMANY)

The interglacial limnic sequence in Neumark-Nord, situated in the Elbe-Saale district in central Germany, was studied by the stable isotope analysis of bulk autochthoneous carbonate. In order to improve profile resolution, we sampled a total of 5 subprofiles over a distance of about 200m in areas where the subprofile concerned had the highest resolution. According to stratigraphic pollen analyses, the profile segments examined cover the transition from the Late Saalian to the Eemian (Late Saalian, PAZ E1) and the whole interglacial period up to the spread of pine at the end of the Eemian (PAZ E7). The complete profile comprises basin schluff in the lower part, finely laminated calcareous muds in the middle, and redeposited calcareous mud in the upper part. The interglacial sequence is completed by a compact layer of non-redeposited calcareous muds. According to the isotopic analysis findings (given as delta values in ‰ versus PDB), the carbonate content initially determined by clastic carbonate of marine origin (Triassic formation: C-13 ca. 1‰; O-18 ca. 0‰) was replaced by autochthonous limnic carbonate during the transition from the end of the Saalian glacial to interglacial conditions. The boundary can be seen in the isotope curves as a clear transition to negative delta values (C-13 ca. -3‰; O-18 ca. -6‰). Warm climatic conditions began in PAZ E4a. The range of the climatic optimum in the Eemian (PAZ E4b to 5) is characterized by the relatively heavy oxygen isotope values (O-18 ca. -2‰) for carbonate within the sequence studied. The rise in the carbon isotope values to about 8‰ indicates continuously increasing eutrophication in the lake, which reaches a maximum in PAZ 5. Another increase in eutrophication (C-13 up to +5‰, O-18 ca. -3‰) can be seen in Pinus PAZ (E7). As previously found from several sediment sequences in central and northern Germany, the results confirm that warm climatic conditions with just minor oscillation prevailed during the middle Eemian and during the climatic optimum of the Eemian.