The removal, cutting away, or erosion of earlier deposits, features, or stratigraphic surfaces by later natural or human actions, producing a truncated stratigraphic profile in which original layers or portions of features are missing or severed.

Principle

Because truncation eliminates parts of the stratigraphic record, an absence or reduction of earlier material in a profile may reflect removal rather than original non‑occurrence; therefore stratigraphic completeness cannot be inferred from surviving deposits alone.

Demonstration

Illustrative scenario → Ploughing and shallow colluvial erosion remove the upper portion of a buried Roman occupation layer. Recognition → Edges of truncated features, sealing unconformities, and truncated cut profiles are documented. Action → Field team records truncation surfaces, alters sampling to target surviving margins, and seeks off‑site or deeper contexts for missing evidence. Consequence → Interpretations of settlement intensity or absence are revised to account for selective loss of the record.

Misapplication

Interpreting the absence of early features or artifacts as proof there was no earlier occupation without testing for truncation. Semantic error: equating current absence with original absence ignores destructive overprinting processes.

Consequence

Failure to identify truncation can lead to underestimates of past activity, misdating of deposits, inappropriate sampling strategies, and incorrect assertions about site chronology and extent; correct identification prompts targeted strategies (edge sampling, deeper testing, coring) to recover residual evidence.

Reversal

Where truncation is shallow, localized, or patchy, underlying features may survive intact in protected pockets; conversely, in periglacial, fluvial, or heavily reworked urban contexts truncation can be complete and preclude recovery of earlier horizons, limiting possible inference.

Boundary

Clearly within: a stratigraphic profile where later excavation or ploughsoil has removed the tops of earlier features. Boundary case: partial reworking that removes artefact surfaces but leaves feature bases. Clearly outside: bioturbation that mixes but does not remove whole deposits, or primary deposition processes that never produced the missing layer.

Semantic Tension

Preservation versus detectability: truncation destroys evidence (reducing preservation) but also creates recognizable surfaces that, if recorded, inform on destructive processes; analysts must balance interpreting absence against documenting truncation itself.

Synthesis

Truncation should be read as an active process that converts former positive stratigraphy into negative evidence; robust interpretation demands explicit recording of truncation surfaces and strategies to seek residual or off‑profile archives.