Geosite introduction of Aso

14.Aso Yellow Soil (Aso Odo) Geosite

Aso Yellow Soil (Aso Odo) Geosite

Environmental and cultural gifts from the great volcano

This geosite offers evidence of the long-standing local practice of using ores deposited by the volcano. Aso Yellow Ochre, also called limonite, is a type of soil used in many products even today. It contains approximately 70% iron, which gives it its yellow color.

Large quantities of red iron oxide have been excavated from burial mounds nearby, leading scholars to conclude that the ancient people of Aso burned yellow ochre to produce the pigment. In that era the red earth was called "ni," and in China it was prized as an elixir of health and immortality. The Gishiwajinden, a third century Chinese historical text, includes many mentions decorative and ceremonial items using ni being presented as gifts by Queen Himiko of the ancient Japanese realm of Yamatai to the Chinese kingdom of Wei.

Aso Yellow Ocher (Limonite)

Aso yellow ocher, a lacustrine deposit heavy in iron, is distributed in the alluvial plains of Asodani Valley's central and western areas. It is the raw material for producing iron ore and red iron oxide pigment, and is also used in desulfurizing agents and livestock feed.