Layer

A unit of stratigraphy, greater than 1 centimeter thick, often part of a bed. Layers are identified by archaeologists and the boundaries between them are often well-marked, where deposition of one layer is separated from the next by a clear interval or change in texture, color, or mineralogy. Some are not clearly demarcated as deposition of one layer may merge with another so that boundaries between them are unclear, or a layer may change in composition from place to place.

A unit of stratigraphy. Sediments and soils on an archaeological site are split up into layers by the excavator. In many cases, the boundaries between them are well marked, where deposition of one layer is separated from the next by a clear interval or change in texture, colour or mineralogy. However, some sequences are not so conveniently split up. Deposition of one layer may merge into another so that boundaries between them are unclear, or a layer may change in composition from place to place. In such cases, it is important that the excavator records exactly what has been found in as objective a manner as possible.