The traditional stratigraphic classification systems and codes evidently have had limitations when applied to Quaternary and Precambrian geology (see e.g. NACSC, 2005).
Especially challenging are the intensely deformed Precambrian terrains with complex metamorphic and plutonic rock assemblages. Consequently, the stratigraphic classification and procedure have not been formalized in the Precambrian of Finland. Nevertheless, the new stratigraphic concepts developed by international stratigraphic organizations and documented in publications by the International Union of Geosciences (IUGS), the International Commission of Stratigraphy (ICS) and the North American Commission on Stratigraphic Nomenclature (NACSN) have opened new insights in application of stratigraphy.
In 2005, the Stratigraphic Commission of Finland (SCF) was founded by the National Geological Committee of Finland. The role of SCF is to provide guidance for stratigraphic procedure, terminology and revision of geological units in Finland ( Strand et al 2010).
Geological Survey of Finland (GTK) has published the first seamless bedrock map database (DigiKP200) and a database for stratigraphic geological units (FINSTRATI) was developed during the DigiKP project (2006-2009). Almost 2000 lithostraticgraphic or lithodemic units were generated and described during the project. The nomenclature was generated according to international rules (NACSN, 2005) and with co-operation of the SCF. In the future the FINSTRATI database is maintained by GTK in collaboration with the Precambrian sub-commission of the SCF (see figure). The database now records information on all Finland stratigraphic units (bedrock) and their usage in literature, making it a centralised reference point for all Finland stratigraphic unit information.
1:200 000 bedrock map is based on the seamless bedrock map database (DigiKP) which is produced from the most relevant bedrock maps in the database project during 2006-2009. The original map database is composed of diverse scaled bedrock maps but it is generalised into the map scale of approximately 1:200 000 which is the main product of the GTK’s bedrock map database. Among lithological coding it contains hierarchical lithostraticraphical or lithodemic classifications linked into the Finstrati system.