Fig. 3From: Continental weathering as the source of iron in Jurassic iron oolites from SwitzerlandA Principal component map and B Fe/C-ratio map of iron oolite sample from Herznach (H1), showing concentric layering of the iron ooid. C Magnetite cubes growing at the expense of flattened green chamositic iron ooids related to the Windgällen folding events (WG6). D Poorly sorted iron ooids with broken ooid fragments or polyooid as ooid nuclei document ooid transportation processes in the iron oolites from Erzegg (EE-P1). E View from Unteres Furggeli to the eastern Windgällen region. The black Blegi Iron Oolite band (marked red) is clearly visible in the field. F Sampled profile at Erzegg, with interlayers of iron oolite and marls with clay schists (see profile in Fig. 4)Back to article page