In archaeology, the general meaning of horizon is a distinctive type of sediment, artefact, style, or other cultural trait that is found across a large geographical area from a limited time period.[1][2][3] The term derives from similar ones in geology, horizon or marker horizon, but where these have natural causes, archaeological horizons are caused by humans. Most typically, there is a change in the type of pottery found and in the style of less frequent major artefacts. Across a horizon, the same type of artefact or style is found very widely over a large area, and it can be assumed that these traces are approximately contemporary.