A thin bed of calcareous and ferruginous greywacke, Ordovician in age, represents the presumed iron
![A thin bed of calcareous and ferruginous greywacke, Ordovician in age, represents the presumed iron Tenká poloha vápnité a železité droby ordovického stáří reprezentuje předpokládanou polohu železné r](https://webarchiv.lib.cas.cz:443/wayback/20190418160306im_/https://www.gli.cas.cz/en/system/files/users/public/zajic_5/gallery_assist/gallery_1229/prev/3.jpg)
A thin bed of calcareous and ferruginous greywacke, Ordovician in age, represents the presumed iron
A thin bed of calcareous and ferruginous greywacke, Ordovician in age, represents the presumed iron ore layer.