Subject ASC00011r7
The Quarterly journal of the Geological Society of London.
v.56 (1900), Page 84 (1900)
Smithsonian Libraries
BHL Page 41487374
Keywords
section geology shale mudstone flag bed grit fault Sectional fossil map Sectional fossil map Silurian rock sequence Wales Rhayader geological strata Gwastaden Cairn Cambrian Railway-line Gwastaden Rhyd-hir Brook silurian shale