tienpohja
Tienpohja is a geographical term referring to the lower layers of bedrock or glacial till that underlie the soil and are visibly exposed in road cuts or along rivers. It is a Finnish term that literally translates to "road bottom".
In a broader sense, the term tienpohja can also be applied to other areas where the underlying
Tienpohja can be composed of a variety of rock types, including granite, gneiss, and basalt, among others.
In road construction, tienpohja can be of significant interest due to its role in indicating the underlying