Natural

The undisturbed geological deposit beneath archaeological layers, representing soil or sediment not substantially altered by human activity.

Archaeological stratigraphy: The study and interpretation of layered deposits created by natural processes and human activity at archaeological sites. It establishes how archaeologists identify the natural beneath later deposits.
Archaeological excavation: The controlled exposure and recording of archaeological remains through the removal of deposits. Excavators may continue downward until reaching the natural.
Site formation processes: The natural and cultural processes that create, alter, and preserve the archaeological record. Geological processes shape the deposit beneath archaeological evidence.
Anthropogenic soil: Soil substantially formed or altered by human activity. Unlike the natural, it records human modification of the ground.
Law of superposition: The geological principle that, in an undisturbed sequence, older layers lie beneath younger layers. It helps establish the natural deposit’s relative position below archaeological strata.
Test pit: A small excavation used to assess buried deposits, archaeological potential, or ground conditions. Test pits can reveal the depth and character of the natural.
Alluvium: Sediment deposited by flowing water, especially in river valleys and floodplains. Alluvium is a common natural deposit beneath or between occupation layers.
Occupation layer: A deposit formed during human use of a place, often containing artifacts and other activity traces. Its archaeological contents mark human activity absent from the natural.
Stratigraphic unit: A distinct layer or feature recognized and recorded as a unit in stratigraphic investigation. The natural is interpreted as one unit in a site’s broader sequence.
Stratigraphic excavation: An excavation method that removes and records deposits according to their stratigraphic relationships. Recognizing the natural helps define the base of an excavation sequence.

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