This paper describes vertical fine-scale geochemical heterogeneity of Estonian graptolite
argillite (GA). GA samples from Pakri and Saka outcrop sections were collected at 20 cm
intervals for chemical analysis of major and trace elements, including rare earth elements.
The study indicates GA enrichment in U, V, Mo and Pb with respect to the average black
shales and thus confirms the formerly reported data on GA geochemistry in general.
However, the content of enriched elements and other trace metals was recorded to vary …

This paper describes vertical fine-scale geochemical heterogeneity of Estonian graptolite
argillite (GA). GA samples from Pakri and Saka outcrop sections were collected at 20 cm
intervals for chemical analysis of major and trace elements, including rare earth elements.
The study indicates GA enrichment in U, V, Mo and Pb with respect to the average black
shales and thus confirms the formerly reported data on GA geochemistry in general.
However, the content of enriched elements and other trace metals was recorded to vary …