Abstract
The Cambro-Ordovician alum shales in Scandinavia have anomalously high contents of certain trace elements, among them U, V and Mo, when compared to other black shales in the world. Variations in the contents of these elements within the formation show a clear correlation with the stratigraphy. The geochemical signature of the different levels of the stratigraphy is apparent over vast areas of the Baltoscandian Platform but has also proved to be valid for fossiliferous black phyllites in the Caledonian autochthon, the lower nappes and one of the higher nappes. Investigation of the content of U, V and Mo in graphitic phyllites of the Stikke Nappe in the Seve-Köli Nappe Complex of the Stekenjokk area has identified the presence of anomalously high contents of these elements compared to average black shales. The content of these elements in the graphitic phyllites correlates clearly with that found in the Early Ordovician Dictyonema-bearing shales in eastern Trøndelag and on the Baltoscandian Platform; it is, therefore, suggested that these metasediments in Stekenjokk are of the same age.