The geological structure, history of geological development and potential mineral resources of the eastern gulf of Finland
The geological structure of the seabed of the Gulf of Finland is characterised by the development of Archaean - Low Proterozoic crystalline and Upper Proterozoic - Low Paleozoic sedimentary rocks, which are covered by Quaternary (mainly Upper Quaternary) sediments. All economic mineral deposits discovered within the eastern Gulf of Finland are associated with the Quaternary sediments. The natural loose building materials such as sand and sandy-gravel mix have the greatest economic value. A special aspect is a new kind of mineral resource - ferromanganese concretions - a poor manganese ore. In addition, limno-glacial clays can be used as material for building ceramics.