Layer directory
A layer directory is the log (geological record) of the soil layers that are encountered when drilling in the subsoil (e.g. subsoil ).
The drilled layers are recorded, named and described in detail with their depth (depth). For each layer or depth, information can be given about: soil or rock designation, composition ( lithology ), rock formation ( genesis ), thickness, color, mechanical properties, age, water content, consistency , lime content, etc.
The layer index is a basis and an essential part of a drilling documentation and an engineering geological soil report .
The content and form of a list of layers are regulated in DIN 4022 (subsoil and groundwater; naming and describing soil and rock). DIN 4022, which has now been replaced by a European standard, distinguishes three types of layer lists in its three parts:
- List of strata for boreholes without continuous extraction of cored samples
- Layer index for drilling in rock (solid rock)
- Layer index for boreholes with continuous extraction of cored samples (loose rock)