Palaeoclimate records from OIS 8.0-5.4 recorded in loess-palaeosol sequences on the Matmata Plateau, southern Tunisia, based on mineral magnetism and new luminescence dating

Mineral magnetic studies of loess-palaeosol sequences on the Matmata Plateau, southern Tunisia, coupled with a new chronology based on luminescence dating, confirm the presence of at least four phases of pedogenesis during the period 100-250 ka. Inter-site correlations between the reddened fersiallitic palaeosols confirms that, despite modern gullying processes, the records are regional and repeatable. The palaeosol magnetic signal is controlled by the formation of secondary ferrimagnetic minerals, which may be easily detected by magnetic susceptibility and frequency-dependent susceptibility measurements. Comparison of the magnetic record with global proxy climate records shows a correlation with loess-palaeosol sequences in China and the marine oxygen isotope (OI) record during stages 8.0-5.4. Preliminary attempts to infer palaeoprecipitation levels from modern analogues of soil magnetism-climate associations suggests that during the periods 100-120 ka and similar to 200 ka precipitation was > 400 mm a(-1), compared with modern precipitation < 150 mm a(-1). (C) 2001 Elsevier Science Ltd and INQUA. All rights reserved.