The Agriculture of Glamorganshire. 
167 
Geological Features. — The older geological formations are 
the Silurian, the Old Red Sandstone, the Mountain Limestone, 
the Millstone-grit, and the Coal-measures ; whilst the newer 
formations are the Permian, the Trias, the Keuper, the Rhaetic 
teds, the Lower Lias, and the Alluvium. The whole of these 
formations crop up in a greater or less degree throughout the 
county, and become the base on which the surface soil rests. 
The Silurian formation is met with on the eastern boundary 
near Cardiff. The Old Red Sandstone appears in patches to 
the north-east of Cardiff and in the neighbourhood of Bridgend, 
and it also forms a strip across the whole of Gower. The 
Mountain Limestone and Millstone-grit form respectively the 
outer and the inner ring encircling the whole of the Coal- 
measures. The extent of the coalfield carries these two forma- 
tions beyond the boundary of the county on the west, north, 
and east, excepting a comparatively small area at Dowlais on 
the north-east corner of the county, where the Mountain Lime- 
stone is worked and used for fluxing the iron ore in the 
furnaces. The Coal-measures occupy fully two-thirds of the 
whole area of the county, viz. the hill districts to the north and 
north-west. The Permian formation is met with in the neigh- 
bourhood of Llantrissant. The Trias appears at Radyr near 
Cardiff. The Keuper is found on the coast at Penarth. The 
Rhaetic beds are also met with on the shore-line near Penarth. 
The Lower Lias extends over the greater portion of the Vale of 
Glamorgan. Alluvial deposits chiefly exist near the mouths of 
the various rivers, and in some parts of the valleys through 
which they flow. The principal alluvial deposits are the East 
and West Moors, near Cardiff ; the valley of the river Ely, near 
Peterston ; the Sully and the Flemingstone Moors ; and the 
Penllyn Moors, near Cowbridge. The term " moors " is asso- 
ciated in most men's mind with "heather," but the marshv 
grass lands of this and the adjoining county of Monmouth are 
known by this name. 
Whilst the Coal-measures occupy the first place in the county, 
as far as area is concerned, the Lower Lias is second in this 
respect, and the Mountain Limestone comes next. The other 
formations occupy only small areas, and are, in a manner, of 
more importance to the geologist than the agriculturist. The 
Lias and the Mountain Limestone formations are frequently 
contorted, and disturbed in their conformability, and inter- 
spersions of patches of other rocks are common. The quality 
ot the surface soil varies very much, in consequence of the dis- 
turbed state of the strata. The surface deposits frequently 
differ so materially from the subjacent rocks, owing to denuda- 
tion and other causes, that the formation on which they rest 
bears little or no relation to them. 
