3 Context and Archaeological Relationships

Contexts as units of evidence

A context is a distinct deposit, cut, or other stratigraphic unit identified during excavation. It is the basic unit used to record archaeological evidence: each context receives a unique identifier and is documented separately so that its characteristics, contents, location, and relationships can be analyzed later. A context is not automatically a complete activity or a single moment in time; interpretation depends on its physical properties and its relationships to other contexts.

Contexts are identified through observable differences, including boundaries, color, texture, composition, and inclusions, as well as their relationships to nearby deposits and features. A context record typically describes what was observed and where it was found. Plans, section drawings, photographs, and notes preserve its position and physical relationships. Because excavation removes deposits, careful documentation must allow others to understand and reassess the evidence afterward.

Deposits, cuts, fills, and features

A deposit is material that has accumulated or been placed in a location. It may result from natural processes, such as flooding or soil formation, or from human actions, such as dumping, construction, or occupation. Deposits are often recorded as positive contexts because they consist of material present in the ground.

A cut is a boundary created when material is removed or displaced, for example, when someone digs a pit, ditch, or foundation trench. It records the removal of earlier material rather than a body of material itself. Its shape and extent can be observed where it truncates other deposits. Material later placed within the cut is recorded separately as one or more fills.

A feature is an archaeological entity recognized through one or more contexts. The feature is the interpreted whole; its contexts are separately observed units that provide evidence for that interpretation. Keeping a cut distinct from its fills helps distinguish the act of digging from the later processes that filled the cut.

Reading a filled pit

Consider a pit dug into an earlier soil layer:

• Context 10: an earlier soil deposit.

• Context 11: the pit cut, which truncates Context 10.

• Context 12: a lower fill inside the cut.

• Context 13: an upper fill above Context 12.

The pit feature consists of the cut (Context 11) and its fills (Contexts 12 and 13). The sequence shows that Context 10 existed before the pit was dug, Context 11 marks the removal of material, and the fills entered the pit afterward.

Finds from a fill are evidence associated with that deposit, but they do not necessarily date the original cutting event exactly. Material may have been residual, redeposited from earlier deposits, or introduced later.

Establishing relative sequence

Stratigraphic relationships establish the relative sequence of events. If one deposit lies above another without disturbance, the upper deposit is generally later. If a cut truncates a deposit, the cut is later than the material it removed. A fill inside a cut must postdate the creation of that cut. These relationships provide relative order; they do not, by themselves, give calendar dates.

Contexts may be earlier than or later than another context, such as a layer beneath a later undisturbed deposit or a fill deposited after a cut was made. They may be contemporary when evidence supports formation at the same time, although contemporaneity can be difficult to establish from stratigraphy alone. Contexts may also be unrelated or uncertain when no direct physical relationship is visible or the evidence is insufficient.

A direct relationship must be distinguished from an assumption based only on proximity. Two deposits beside one another are not necessarily the same age; a clear boundary or other evidence is needed to establish how they relate. Where deposits meet, their contact may show that one abuts, overlies, or is cut by another.

Organizing relationships in a Harris matrix

A Harris matrix is a diagram that represents stratigraphic relationships in a readable structure. It shows which contexts are earlier or later and helps identify separate sequences. The matrix is an analytical model built from observed relationships, not a substitute for original context records, plans, or sections.

Accurate records preserve the evidence used to construct and assess the matrix. A matrix organizes observed relationships, while the records and drawings retain details about each context and its physical position.

Why context relationships matter

The archaeological record is not simply a collection of objects. An artifact’s context—its location in a deposit, cut, or fill and its relationship to other units—helps establish how it entered the ground and how it relates to past activity.

Stratigraphic analysis combines context relationships with other evidence, including artifacts, environmental remains, and scientific dating, to develop interpretations of a site’s sequence. Recording observed evidence separately from interpretation makes conclusions more transparent and open to reassessment. Accurate context records and a stratigraphic matrix preserve and organize the evidence so interpretations can be checked and revised.