In anthropology and archaeology, a datum is a fixed reference point used for measurement, mapping, and spatial control during excavation or survey. It ensures that all artifacts, features, and stratigraphic layers are recorded in relation to a consistent coordinate system.
🌍 Definition
- Datum: A permanent, established point of reference from which spatial measurements are taken.
- Purpose: Provides accuracy and consistency in recording artifact locations, site features, and stratigraphy.
- Analogy: Like a “zero point” or benchmark in surveying.
🔑 Characteristics
- Fixed Location: Often marked physically (e.g., a stake, nail, or concrete block).
- Elevation Reference: Used to measure vertical depth of artifacts and features.
- Horizontal Control: Serves as the origin for grid systems laid across excavation sites.
- Permanent Marker: Ideally placed in a stable, undisturbed area to last throughout the project.
- Linked to Survey Systems: Can be tied to national or global coordinate systems (e.g., GPS, USGS benchmarks).
📚 Anthropological Significance
- Excavation Accuracy: Ensures artifacts are recorded in precise spatial relation.
- Comparative Studies: Allows archaeologists to reconstruct site stratigraphy and spatial organization.
- Mapping: Datum points anchor site maps, excavation grids, and 3D reconstructions.
- Standardization: Critical for scientific rigor and reproducibility in archaeological documentation.
🛠 Examples
- Single Datum: A nail in bedrock used to measure all excavation depths.
- Site Grid Datum: A corner stake marking the origin of a square excavation grid.
- Regional Datum: A GPS coordinate tied to a national survey system.
- Museum Contexts: Provenience data often references the original excavation datum.
✨ Summary
A datum is a fixed reference point used in archaeology and anthropology to ensure accurate spatial recording of artifacts, features, and stratigraphy. It anchors excavation grids and maps, making site documentation consistent and scientifically reliable.
