Natural Magnetic Archives of Past Global Change

Rock magnetic parameters of sediments reflect palaeoenvironmental and palaeoclimatic conditions during deposition in the marine and in the continental realm. The processes which lead to enhancement or degradation of the magnetic properties are well known – though not completely understood. They include variable terrigenous material influx, organic and inorganic in situ formation of ferromagnetic minerals and diagenetic destruction of these minerals. Cyclical changes in the magneticmineral assemblages occurring at the orbital periodicities involved in standardMilankovitch theory have been observed in numerous sedimentary records, at least during the last seven million years. This confirms the relationship between rock magnetism and past global change. Quantitative interpretation of the magnetic signals, however, is still in its infancy and is hampered by the complex interplay of the signal formation processes.