borelogg

Borelogg is the documented record of subsurface conditions encountered during drilling boreholes for geotechnical, environmental, or hydrogeological investigations. The term is frequently used in civil engineering and geology and is sometimes spelled borelog or borehole log; in some languages, such as Scandinavian ones, borelogg is the common form.

A borelogg typically covers several key elements. The borehole identification and location, the drilling method and primary disturbance, the depth ranges sampled or tested, and the interval-by-interval description of materials encountered. Lithology is described, including rock type, soil type, color, texture, grain size, moisture, and degree of weathering. Depth to groundwater or perched water, water quality notes, and any weathered zones are recorded. Samples recovered (disturbed and undisturbed) are listed with depths and numbering. In-situ tests (for example, soil tests, cone penetration tests, or standard penetration tests) and any laboratory test results on recovered samples are noted. Modern borelogs may also include downhole geophysical or borehole imaging data.

Borelogs come in various formats, ranging from simple field logs to standardized digital records that integrate with GIS and geotechnical design software. They are used to build a stratigraphic column, assess foundation conditions, evaluate groundwater conditions, and support environmental and remediation planning.

The borelogg provides a foundational reference for engineers, hydrogeologists, and environmental professionals, enabling informed decisions about construction feasibility, risk assessment, and mitigation strategies.