Andosols

Soils with a vitric or andic horizon (slightly to moderately weathered horizons in pyroclastic deposits dominated by short-range-order minerals, notably allophane and imogolite) starting within 25 cm from the soil surface. In addition, they may have a histic, fulvic, melanic, mollic, umbric, ochric, duric, or cambic horizon. Other diagnostic horizons (unless buried deeper than 50 cm by volcanic deposits) are absent.

Andosols occur throughout the world where volcanic activity is common, especially in the circum-Pacific region and along the mid-Atlantic Ridge. 

 

To the Andosol Picture Gallery