Many soils in California have horizons (layers) with exceptionally low K[sub.sat] values that severely limit downward percolation, such as cemented layers (duripan
, petrocalcic), claypans (abrupt increases in clay content) and strongly contrasting particle size distributions.
Moreau AMSDS, Costa LMD, Ker JC, Gomes FH (2006) Genesis of hardened horizons, fragipan and duripan
in soils of the coastal tablelands of south Bahia.
They have been denoted with different names such as silcrete in the USA; talpetate in Nicaragua; hardpan, duripan
, and cangahua in Colombia and Ecuador; cancagua, moromoro, tosca, and nadis in Chile; hardpan in Peru; and kora and masa in Japan .
Older soils generally tend to be more complex and show more extensive duripan
(caliche) development and clayrich B-horizons (Othberg, 1994).
Aridisols will have one or more of the following features within 100 cm of the soil surface: a calcic, cambic, gypsic, natric, petrocalcic, petrogypsic, or a salic horizon, or a duripan
or an argillic horizon.
Depending on the age and the degree of washing, accumulation horizons of silica (duripan
) or of iron oxides (plinthite and ferruginous crusts) may occur.
Tepetates are volcanic soils that consist of a duripan
exposed through erosion of the overlying soil.
(Chapter 3)--A relatively impermeable layer in soil composed of cemented silica.
. A soil layer hardened and cemented by silica.
Subsurface horizons cemented by silica found less than 3 ft (1 m) below the soil surface are known as duripans
. In arid regions, they are often calcic, and the soils containing them are therefore classified as duripan
phases of calcisols.
* Caliche and duripans
are layers of soil in which chemicals cement soil particles together.