摘要
In the Loess Plateau of China, the orbitally induced climatic oscillations are generally expressed by alternation of pedogenetic and sedimentary events (pedosedimentary events). In the last years, investigations at different localities revealed that complete loess-soil sequences contain 37 major soil stratigraphic units which are spatially correlativ. Recent studies have demonstrated that many of these soil units are polygenetic (polycyclic), which were formed by several pedogenetic stages interrupted by dust deposition stages, evidencing climatic oscillations within the interglacial periods. Some loess units contain also clearly ex-
