Glacial Drift of the Central Plain 45 



country, but most of the southern mountains are formed 

 of Old Eed Sandstone, Trliicli occupies a large area, and 

 also rises from under the limestone of the southern portion 

 of the central plain to form isolated mountain ranges. 

 In the north-east and south-east there are considerable 

 areas of Ordovician and Silurian rocks, in the centres 

 of which rise lofty mountains of granite. Finally, the 

 extreme north-east is a plateau country of basalt over- 

 lying chalk and Trias ; these are almost the only rocks of 

 later date than the Palaeozoic existing in the country, with 

 the exception of glacial deposits which overlie the older 

 rocks in many places. 



In sharp contrast to Scotland, with its almost uniformly 



siliceous soils, by far the greater part of the 



Carboniferous j.^^,^ ^^ which the soils of Ireland are based 



Lunestone . r^ i • f 



Plain. is the Carboniferous Limestone, which forms 



the great central plain, extending from 

 Dublin on the east coast right across the country to 

 Gralway on the Atlantic, and from Fermanagh on the 

 north to the borders of Co. Cork in the extreme south. 

 Most of the glacial drift with which this plain is largely 

 covered contains much lime, and it is to this calcareous 

 soil, together with the equable moist climate, that the 

 excellent Irish grasslands, justly famed for cattle-raising, 

 are due^. Conspicuous among the glacial accumulations 

 are the dry grass-covered gravel ridges known as "eskers." 

 In Co. Cavan and other places " drumlins " of boulder-clay 

 with steep rounded flanks furnish loamy and often stony 

 soils. In spite of their form, the drumlins are often selected 



1 In 1910 there were 23 head of cattle to every hundred acres of land 

 of all kinds in the whole country, while in some counties this number 

 was considerably exceeded ; thus Co. Meath in Leinster had 38 head 

 to the hundred acres. These figures compare with (in 1909) less than 

 16 for England and only 6 for Scotland. Some of the English counties 

 however, in the Midlands and west, show high figures, e.g. Cheshire 28, 

 Leicester 27, Cornwall 25 ; Anglesey in Wales had nearly 32. 



