LATE PLEISTOCENE CLIMATIC VARIATIONS AT ACHENHEIM, FRANCE, BASED ON AMAGNETIC-SUSCEPTIBILITY AND TL CHRONOLOGY OF LOESS

New field investigations of the Achenheim sequence (Alsace, France) al low for the characterization of variations in the low-field magnetic s usceptibility over most of the last climatic cycle, i.e., the past 130 ,000 yr. New stratigraphic data and thermoluminescence measurements pe rmit reassessment of the previous chronological interpretation of the Upper Pleistocene at Achenheim. A high-resolution analysis of magnetic susceptibility discloses the occurrence of a fine-grained ''marker'' horizon which was also found recently in another section. This horizon is interpreted as a small-scale dust layer deposited prior to the mai n interval of loess deposition. The horizon, deposited at the marine i sotope stage (MIS) 5/4 boundary, has been found in other loess sequenc es and is especially prevalent in central Europe. It is characterized by low susceptibility values and a grayish color. New thermoluminescen ce dates indicate that the loess deposition took place after the MIS 5 /4 boundary, i.e., after 70,000 yr, These results are consistent with the Greenland GRIP ice-core dust record which also demonstrates a dust y atmosphere after 72,000 yr ago. On a more regional scale, the Achenh eim loess sequence demonstrates a reliable correlation between the wes tern side of the Eurasian loess belt and the dust record of the Greenl and ice cores. (C) 1998 University of Washington.