Subject ASC0002da0
The Quarterly journal of the Geological Society of London.
v.34 (1878), Page 877 (1845)
Smithsonian Libraries
BHL Page 38636467
Keywords
section lower footbridge skelgill scale light blue flag mudstone calcerous concretion phacops zone argenteus encrinurus silurian ashgill shale flaggy geology Skelgill flags graptolites convulutus spiralis diplograpsus tamariscus calcareous Lower Footbridge Skelgill