The accurate engineering description of soils and rocks is fundamental to the success of any civil engineering or geo-environmental site investigation.
In the vast majority of cases the materials recovered from the ground are seen only once and it is in this very short space of time that the geotechnical/geo-environmental-engineer must decide on the composition of the soil and hence describe and record it.
These descriptions invariably form the building blocks of conceptual ground models and are the basis for important design decisions, work often carried out by different personnel from another organisation.