Downland Soil
The soil profile of chalk downland in England is a thin soil overlaying the parent chalk. Weathering of the chalk has created a characteristic soil known as rendzina. Unlike many soils in which there are easily distinguished layers or soil horizons, a chalk rendzina soil consists of only a shallow dark humus rich surface layer which grades through a lighter brown hillwash containing small pellets of chalk, to the white of the chalk itself. This is largely because of the purity of the chalk which is here about 98% calcium carbonate and the consequent absence of soil-building clay minerals which are abundant, for example, in valley floors.
Steep slopes on chalk downland develop a ribbed pattern of grass covered horizontal steps a foot or two high. Although subsequently emphasised by cattle and sheep walking along them, these terracettes (commonly known as sheep tracks) were formed by the movement of soil downhill, a process known as soil creep.
Read more about this topic: Downland
Famous quotes containing the word soil:
“Have you seen but a bright lily grow
Before rude hands have touch’d it?
Have you mark’d but the fall of the snow
Before the soil hath smutch’d it?
Have you felt the wool of the beaver,
Or swan’s down ever?
Or have smelt of the bud of the brier,
Or the nard in the fire?
Or have tasted the bag of the bee?
O so white, O so soft, O so sweet is she!”
—Ben Jonson (1572–1637)