1848. | SEDGWICK ON THE SKIDDAW SLATE. 217 
4. Over the preceding rocks, and in a conformable position, comes 
a group about 1500 feet thick, chiefly composed of slate and flagstone 
of a dark colour. All parts of this group are more or less calcareous, 
but the lowest beds contain so much calcareous matter as to pass into 
a limestone (Coniston limestone). 
5. Next comes a group of coarse, hard, light-coloured grit and 
sandstone. It is of variable thickness, sometimes however much 
thicker than the preceding group ; and it is the commencement of 
a great physical changé im the nature and colour of the deposits. 
6. The preceding group is followed by a complex deposit contain- 
ing many thin beds like those last described, but also containing 
large masses of roofing-slate and flagstone (Ireleth slate). It is of 
very great thickness, and in its lower division contains in some places 
a very thin band of impure concretionary limestone. 
7. Over the preceding group (and separated from it by beds with 
a somewhat intermediate type) comes the complicated deposit, com- 
posed of sandstone, flagstone, &c., which is developed between the 
hills immediately north of Kendal and the valley of the Lune near 
Kirkby Lonsdale. In the upper part of this series are some greenish 
and reddish flagstones, which mineralogically resemble the tilestone of 
the Silurian system, and appear to occupy the same place in the series. 
8. Old red conglomerate, containing here and there concretions of 
limestone, and occasionally rolled fragments of limestone derived from 
the older rocks (Coniston limestone, &c.). As a general rule, this 
deposit is perfectly unconformable to all the older rocks, fillmg up the 
inequalities and hollows on their outskirts in discontinuous masses, 
and generally at a comparatively low level, reminding us of the 
shingles of an ancient shore or shallow sea. 
9. Carboniferous limestone, sometimes resting conformably on the 
upper beds of the red conglomerates ; and, where they are wanting, 
resting unconformably upon the older groups. In its long uncon- 
formable range it forms a belt about the Cumbrian cluster of moun- 
tains, so as to rest near Whitehaven on the Skiddaw slate, and near 
Kirkby Lonsdale upon the red beds of tilestone. 
Ideal section from Skiddaw Forest to the calcareous hills of Westmoreland. 
1. Granite-centre of Skiddaw Forest. 
2. Skiddaw slate; 2 a, metamorphic; 2 3, 
unchanged. 
= 3. Green roofing slate and porphyry, &c. 
4, Coniston limestone ; 4 a, limestone ; 44, 
calcareous flagstone. 
. Coarse-grained siliceous grits. 
. Ireleth slates, &c. 
. Slaty flagstone ending in tilestone. 
Old red conglomerate. 
. Carboniferous limestone. 
OOnIan 
The accompanying section is so far ideal that it leaves out all con- 
tortions and dislocations ; but it gives the right sequence, and may 
by the vast deposits forming the oldest and highest ridges of North Wales. In 
Cumberland this group (No. 3) is, 1 think, not less than 20,000 or 30,000 feet in 
thickness. ; 
