Stable isotopic evidence for Middle Pleistocene environmental change from a loess-paleosol sequence: Karlich, Germany

Loess-paleosol sequences are important terrestrial archives of palaeoenvironmental change. Such sequences are rich in pedogenic carbonate, the oxygen and carbon isotopic values of which can provide important palaeoenvironmental information. Although some studies have pioneered the use of O and C isotopes in loess-paleosol sequences, they are not routinely used as palaeoclimate proxies. In this study we analysed the sedimentology, micromorphology, geochronology and isotopic geochemistry of a Middle Pleistocene loess-paleosol section, located at Karlich, Germany. The section studied correlates with the Elsterian glacial (MIS 12) and Holsteinian interglacial (MIS 11). Embedded tephra layers yielded Ar-40/Ar-39 ages of 466 +/- 3ka, 447 +/- 1ka and 361 +/- 3ka. The sedimentology and micromorphology of the sequence record a shift from accretionary loess accumulation (MIS 12) to prolonged pedogenesis at a stable land surface (MIS 11). Soil carbonate O-18 values record an enrichment of approximate to 3 parts per thousand during the accumulation of the loess, reaching peak values comparable with those found in the MIS 11 soil. The O-18 signal is interpreted as reflecting temperature, highlighting the potential of O-18 analysis of European loess soil carbonates as a means of reconstructing palaeotemperature history.