Six bentonite samples from the Silurian (Wenlock) Steinsfjorden Formation collected in the Ringerike District of Norway have been mineralogically and compositionally characterised. The results are used to stratigraphically correlate three bentonites in the Ringerike District. The bentonites crop out in rocks deposited in widely varying sedimentary environments in a relatively small geographic region highlighting dynamic and varied sedimentary environments in the area during middle Silurian times. Correlation with bentonites from rocks of similar age along the north-south axis of the Oslo paleo-rift was not possible. A potential correlation between one bentonite at Ringerike with bentonites in the Slite Formation on the island of Gotland is proposed. This suggests that although there is evidence of significant volcanic activity preserved in the Lower Palaeozoic rocks of Scandinavia and northern Europe, spatial distribution and preservation of ash is highly variable.
Note on the composition and mineralogy of Wenlock Silurian bentonites from the Ringerike District: Implications for local and regional stratigraphic correlation and sedimentary environments