Some applications of paleopedology in Japan

• Published in: Geoderma Vol. 22; no. 1; pp. 45 - 60
• Main Authors: Kato, Y., Matsui, T.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.1979; Elsevier BV
• Subjects: Japan; Japan
• ISSN: 0016-7061; 1872-6259
• DOI: 10.1016/0016-7061(79)90039-9

Paleosols in Japan consist of buried soils and relict soils. The former occur primarily in tephra deposit, whereas the latter occupy old land surfaces in various parts of the country. The buried soils affect construction of highways and urban development. The relict soils pose problems in forestry. The paleosols formed in tephra and buried by subsequent volcanic eruptions are chiefly Andosols with their low bulk densities, low solid ratios, high specific surfaces and high water losses. These characteristics are responsible for poor engineering performance of the paleosols and tephras. These have been especially troublesome in the Kanto plain near tokyo and around the Ashitaka Volcano. Some buried soils in tephra, as for example those in the San'in district, are exceptions to the general rule and have desirable properties for construction. Those tephras have clay fractions low in allophane and high in layer-silicate minerals. The buried soils have provided approximate ages of human artifacts through radiocarbon dating of humic horizons. Conversely, identification of artifacts found in buried soils has helped to bracket their ages. Paleosols that are relicts are chiefly members of a Red-Yellow group, many of which seem to be Udults (Ultisols). The soils apparently began forming in warmer past periods but still persist on the land surface. Such soils are strongly acid and very low in plant nutrients, with resulting low productivity when used for forestry or farming. Moreover, such soils are readily subject to erosion because of their landscape positions and poor plant cover.