Slide 1
Undisturbed layers generally put older deposits below newer ones
Archaeological stratigraphy studies layers and their relationships.
In an undisturbed sequence, a deposit underneath another was generally laid down earlier than the material above it.
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The qualification about disturbance is essential. A site is the result of activities and natural processes rather than a perfectly stacked calendar. Archaeologists reconstruct those processes before turning depth into an argument about relative age.
Slide 2
A later pit can carry younger material deeper
A later pit can cut through earlier deposits. Material at the bottom of that pit may therefore be younger than layers beside it at a higher level.
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This example explains why depth alone is insufficient. The edge of the cut establishes a relationship: the pit could only be dug after the deposits it penetrated existed. Recording boundaries can be as informative as collecting objects from inside them.
Slide 3
A find’s recorded context supports its interpretation
An artifact’s location and relationship to other remains form its context.
Removing it without recording those relationships can destroy evidence needed to interpret its use and date.
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A cooking vessel beside a hearth supports a different set of questions from the same vessel reused in a burial. The object has not changed, but its associations have. Context allows an interpretation to extend beyond the artifact’s appearance.
Slide 4
A sequence does not automatically supply calendar dates
Stratigraphy can establish that one event came before another without giving either a calendar year. Other dating evidence can sometimes help anchor that sequence more precisely.
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A sequence of floor, destruction layer and rebuilding establishes an order even before an absolute date is available. That order can test a proposed history of a site. Exact dates add information, but the relationships remain valuable in their absence.
Slide 5
Excavation removes relationships that records must preserve
Excavation removes deposits as it studies them.
Plans, photographs, descriptions and finds records preserve relationships that cannot simply be recreated by digging the same layer again.
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Documentation allows another researcher to examine the reasoning after the physical context has changed. This makes a site archive part of the evidence, not an administrative extra. A well-recorded excavation leaves questions open to later analysis and improved methods.
Sources
- Archaeological Research Methods
OpenStax, Rice University
- What is Archaeology?
Society for American Archaeology
- Teaching Archaeology
Society for American Archaeology