ABSTRACT
The knowledge of the origin and distribution of loess is prerequisite to the study of loess landform, structure, physical and mechanical properties, and geohazards. In 1841, J. D. Charpentier contended that loess is a very fine glacial clay deposit that resulted from the melting of glaciers and later hypothesized a glacial origin. The mineral and chemical compositions and other components of primary loess are almost identical in space; thus, hypotheses other than that related to the aeolian origin of loess are difficult to support. In 1920, considering the homogeneity of loess with vast spatial distributions, K. Keilhack proposed an extraterrestrial origin. South American loess presents a broad geographic distribution extending across the Chaco—Pampean Plain of Argentina and neighboring areas of Uruguay, southern Brazil, Paraguay, and the eastern Bolivia lowlands. The distribution pattern of loess in China is not only controlled by mountains and topography, but also related to the zonal distribution of climate.
