Geochemical Reconstruction of the Provenance, Tectonic Setting and Paleoweathering of Lower Paleozoic Black Shales from Northern Europe

Lower Paleozoic black shales from Estonia, Sweden, and Russia were analyzed for major trace elements to reconstruct the provenance, tectonic setting, paleoweathering conditions of these shales. The shale is highly enriched in U, V, Mo, Pb (except samples Sweden where slightly enriched), SiO2, Fe2O3, K2O, TiO2 depleted CaO, Na2O, MnO, with respect average provenance signatures (Th/Sc versus Zr/Sc, Al2O3 TiO2, Zr plots, Zr/Sc ratio) Baltoscandian suggest that they derived rocks intermediate felsic composition recycled sediments. likely region was Paleoproterozoic igneous metamorphic basement southern central Finland, which consists predominantly (acidic gneisses, volcanics, microcline granites migmatites) (small granitic intrusions large rapakivi granite intrusions), reworked older Ediacaran Cambrian sediments; however, proportion clastic input sources not uniform three regions studied. discrimination settings source materials using SiO2 K2O/Na2O plot a new discriminant method (APMdisc) favors passive margin setting. Chemical Index Weathering (CIW) indicates material studied has experienced an intense degree chemical weathering. indices (Chemical Alteration CIA CIW) also show significant secondary potassium enrichment.