Soil Order

Raw Soils [W]

Infant soils that may never grow older because of active erosion or sedimentation.

Raw Soils are very young soils. They lack distinct topsoil development or are fluid at a shallow depth. They occur in environments where the development of topsoils is prevented by rockiness, by active erosion, or by deposition.

Raw soil, Denniston Plateau.
Raw soil, Denniston Plateau.
Raw Soil on sand.
Raw Soil on sand.


Raw Soils are scattered throughout New Zealand, particularly in association with high mountains (alpine rock areas and active screes), braided rivers, beaches and tidal estuaries. They cover 3% of New Zealand.

View map View map of Raw soils.

Physical properties

Raw Soils have no B horizon, and a topsoil is either absent or less than 5 cm thick. Most occur in environments with active erosion or deposition. Fluid soils have a continuously high water-table.

Chemical properties

Fertility is limited by lack of organic matter and nitrogen deficiency.

Biological properties

Vegetation cover is sparse and often consists of ephemeral herbaceous plants, mosses, or lichens.

Soil groups

Soil orders are divided into soil groups based on variation in factors such as drainage status, parent material, chemical and physical properties

[WG] Gley Raw

Periodically wet

[WH] Hydrothermal Raw

Soils naturally warmed by geothermal activity

[WX] Rocky Raw

Rock at shallow depths

[WS] Sandy Raw

Dominated by sand or loamy sand to depth

[WF] Fluvial Raw

In sediments deposited by flowing water

[WT] Tephric Raw

In sediments originating as volcanic ejecta

[WO] Orthic Raw

Other Raw Soils