Catena (soil)

[1] Each soil type or "facet" differs somewhat from its neighbours, but all occur in the same climate and on the same underlying parent material.

The term catena (Latin: chain) was first coined by scientist Geoffrey Milne to describe these soil-topography units.

[7] Catenas can also develop on low relief hillslopes, but because less potential energy is available, the redistribution of mass can be dominated by subsurface flow of plasma, a combination of dissolved and suspended solids in soil water.

On a steeper slope in the middle of a catena, erosion (surface runoff) is faster, so facets are typically thinner and drier.

[10][11] On a permeable basic rock such as chalk, the catena may consist of thick brown earths on the flatter facets, with thin rendzinas on the steeper slopes, while the valley bottom may include alkaline fen peat or river alluvium.

A catena is a sequence of soils down a slope, created by the balance of processes such as precipitation , infiltration and runoff.
Cross Section of Dry Zone Catena of Sri Lanka showing relationship to rural land use
Gullies in wet peaty soil in Scotland show where water has run off, before sinking into deeper soils at the bottom of the catena.