The OCG WMS Service showing the Geology of Italy at 1:500.000 scale is based on the digitization of the Geological Map of Italy at the same scale published during the 1970's and 1980's by the Geological Survey of Italy. The layers available are: Chronostratigraphy, lithostratigraphy and lithology.

The database for geological map of Romania at 1:1 000 000 scale had been built on the basis of geological map built by an authors team in 1978 and is organized in two layers (Geologic Unit – lithostratigraphy and Geologic Structure – geological boundaries and faults) and two tables. This has been modified for harmonization in to OneGeology Europe project.