248 FERTILE MARLS OF THE NEW RED SAND-STONE. 



spots. The lower beds are sometimcji 

 ^ full of rolled pebbles. Few of the sand- 



^ stones of this formation are sufficiently 



hard to form building stones— many of 

 the layers consist of loose friable sand, 

 and the marls universally decay and 

 crumble to a fine red powder under the 

 influence of the weather. 

 Extent. — The new red sand-stone extends over a larger portion of the surface 

 of England than any other formation. It commences at I'orbay, in the south 

 of Devon, runs north-east into Somersetshire ; from Bristol ascends both sides 

 of the Severn, accompanies it into the vale of Gloucester, stretches along the 

 base of the Malvern hills, and north of the city of Worcester expands into a 

 gently undulating plain, nearly 80 miles in width at its broadest parL compre- 

 hending nearly the whole of the counties of Warwick and Stafford and the 

 greater part of that of Leicester. From this central plain it parts into two di- 

 visions. One of these runs west over the whole of Cheshire — (in which 

 county it contains salt springs and mines of rock salt) — the western part of 

 Flint, and on the south-west surrounds the county of Lancashire. It is there 

 interrupted by the rising of the older rocks in Westmoreland, but re-appears in 

 the eastern corner of this county, runs north-west through Cumberland, forai- 

 ing the plain of Carlisle — and thence round and across the Solway Frith till it 

 finally disappears about 20 miles north of Dumfries. The other arm, proceed- 

 ing from the towns of Derby and Nottingham, runs due north through Notting- 

 ham and the centre of Yorkshire, skirting the outer edge of the lias, and finally 

 disappears in the county of Durham to the nox'th of the river Tees. The south- 

 ern portion of this arm has a width of 20 to 30 miles, until it reaches the neigh- 

 bourhood of Knaresborough, whei-e it suddenly contracts to 6 or 8, and does 

 not again expand to more than 10 or 12 miles. 



North of Dumfries-shire these rocks are not known to occur in our island 

 In the north-east of Ireland they form a stripe of land a few miles in width, run- 

 ning from Lough Foyle to Lough Neagh, and thence, with slight interruptions, 

 to the south of Belfast. 



Soil. — These rocks, by their decay, almost always produce a deep red 

 soil. Where the red clay and marl predominate, this soil is a red clay or 

 clayey loam of the richest qualify, capable of producing almost every crop, and 

 remarkable therefore for its fertility. It is chiefly in arable culture, because of 

 the comparative ease with which it is worked, but the meadovi^s are rich, and 

 produce good herbage. Where the rocks are more sandy, and contain few 

 marly bands, the soil produced is poorer, yet generally forms a good sandy loam, 

 suitable for turnips and barley. 



In Devonshire, as in the vale of Taunton and other localities, where the lias 

 and the red sand-stone adjoin each other, or run side by side, the difference in 

 the fertility and general productiveness of the two tracts is very striking. On 

 the former, as already observed, good old grass land is seen, but the arable land 

 on the latter produces the richest and most luxuriant crops to be seen on any 

 soil in the kingdom. In this county, and in Somerset, the only manure it eeems 

 to require is lime, on every repetition of which it is said to produce increased 

 crops. The same remarks as to its comparative fertility, apply with more or 

 less force to the whole of the large area occupied by this formation in our island 

 — wherever the soil has been chiefly formed by the decomposition of the rock 

 on which it rests. In some localities (Dumfries-shire) the micaccmis, marly 

 rock is dug up, and, after being crumbled by exposure to a winter's fiost, is laid 

 on with advantage as a top-dressing to grass and other lands. 



In the south of Lancashire, and along its western coast, and on the shores of 

 the Solway, in Dumfries-shirc^ a great breadth of this formation is covered with 

 peat. 



