Subject ASC0003s6v
The geological magazine, or, Monthly journal of geology.
[Decade 1]:v. 4 (1867), Page 251 (1867)
Harvard University, Museum of Comparative Zoology, Ernst Mayr Library
BHL Page 32512100
Keywords
phosphate bed chart strata layer phosphate lime llanfyllin wales rubble shale sandstone retepora favosites orthis parva schist hill limestone hirnant band bala blue quarry geology cross-section Wales geological cross-section Llanfyllin North Wales phosphate north Wales