THE PHYSICAL GEOGRAPHY OF THE PAST. 
251 
Although the Cheviots formed land during early Carboni¬ 
ferous times, we have sufficient evidence to indicate that the 
area was an island , and that we have to look still a little 
further North for the coast of that great continent which was 
drained by the rivers of the Carboniferous period. In Lanark¬ 
shire we find the old Carboniferous beach resting upon the 
old Red Sandstone, and, to a great extent, derived from its 
waste. From the thinning out of all the beds above this, 
there is the strongest possible evidence that, across a line 
drawn from the Firth of Tay to the extreme North of the 
Island of Arran, the shore conditions continued for a very long 
period in Lower Carboniferous times, and that the land rose 
rapidly North of this line,in the region of the Scotch Highlands, 
to a much greater height than it does at the present time. 
In Ireland the Carboniferous Limestone is strongly repre¬ 
sented in Clare, Tipperary, and Queen’s County, its greatest 
development being only about half a degree of latitude further 
south than its greatest development in our own Northern 
Midlands. Here, just as with us, the limestone shows the 
same tendency to give place to mechanically formed deposits, 
i.e., sandstones and shales, further towards the north and 
north-west, indicating, as with us, the direction in which the 
old land lay. That the western portions of Donegal, and of 
Connaught, formed part of this coast there is a great deal of 
evidence to show, and it is probable that the western portion 
of County Kerry was also above water. 
Around the old Silurian Rocks of our Lake District there 
are found thick uneven deposits of Conglomerate and Sand¬ 
stone, belonging to the base of the Carboniferous, and, from 
their irregularity and the rapid way they thin out, it is evident 
that they were beach deposits banked around an island in the 
Carboniferous Sea. There are also similar deposits in the 
southern part of the Isle of Man. 
Having traced the Mountain Limestone of the deep water 
of Central Derbyshire to the north and north-west shore of 
the sea in which it was deposited, we will retrace our steps 
once more to the Derbyshire district, and ascertain what 
becomes of this massive limestone when followed southwards. 
The southern prolongation of the limestone of the Weaver 
Hills plunges, as we have seen, beneath the more recent New 
Red Measures, near Ashbourne, and we see nothing more of 
it until, owing to a series of small folds, it is brought to the 
surface again some 20 miles to the south-east on the northern 
margin of Charnwood Forest. We there find it in eight small 
patches, of which that of Ticknall is the most northerly, and 
that of Grace Dieu the most southerly. 
(To be continued.) 
