The dictyonema shale of Estonia

In the northeastern Baltic, Tremadocian Dictyonema Shale is found in northern Estonia and in the St. Petersburg (former Leningrad) Region in Russia. The formation can be seen in the Baltic Ladoga Cliff forming the southern edge of the Finnish Bay. The Estonian Dictyonema Shale is characterized by low carbonate (Ca, Mg, Mn), Na and high potassium feldspar (K) content. Its trace element composition resembles also to the Scandinavian Alum (Dictyonema) Shale having high concentrations of U, V and Mo. Up to now, only a few investigations related to the geochemistry and lithology of the Estonian Dictyonema Shale have been presented in English. This work was done to give a short review of studies in Russian and Estonian literature. New data about trace element and organic geochemistry were added into this paper. Titles of the references were given in English, the language of the articles and summaries has been mentioned also.