Tutorial:Floors

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Floor Layers
A floor layer is a specially prepared or constructed surface. This can be for many purposes including occupation, walking, cooking or threshing. Floors can be: Different activities produce various floor types. For example, stable floors and threshing floors can be characterised by thickly layered coarse phytoliths which are relics, respectively of dung or cereals, the actual organic matter having been lost by oxidation.
 * 1) Constructed of materials intentionally brought into an area such as plaster, gravel and sand.
 * 2) The local substrate purposefully prepared or modified by sweeping, intentional compaction or occupation trampling. These can lack strong lithological contrasts between the surrounding layers and may be difficult to recognise in an excavation.

Modification of floor layers
Human or animal trampling sometimes acting together with natural puddling can modify, destroy or partially disrupt a surface. Slaking, the reaction of calcium hydroxide with water, causes crust formation on the floor surface. When well developed, the surface can be sealed by a fine laminated crust which is poorly or non-permeable and favours runoff. The features of trampling and associated slaking of a floor are rarely observable because of disturbances by further human activity and later by root and faunal working. Dry and soft materials along with intentionally hardened floors will compact poorly resulting in the size reduction of soil aggregates, thus increasing their vulnerability to weathering by wind.