From the main ridge near Birkbeck Fells an important branch is thrown off in a north-east direction ; but between this and the branch ridge, which has been described as parting from the main ridge at High-street, are two shorter branches separated from the High-street branch by the valley of Mardale, from each other by the valley of Swindale, and from the Birkbeck Fells branch by the valley of Wet Sleddale.
The branch from the principal ridge of the mountains at Birkbeck Fells is known in the part nearest the ridge as Strap Fell. It extends northward in several ridges, separated by intervening vales. Knipe Scar, and the hills of Sbap Moor, Newby High Moor, Ravensworth and Meaburn Moors, and Colby Common, all belong to this branch. The intervening valleys have a general direction north and soutb, and the waters which drain them unite to form a stream which joins the Eden between Kirkby Thoro and Temple Sowerby.
The branches from the main ridge on the south side extend on tho western side of the county a very short distance from the main ridge, =balding in the valley of Grasmere, by which they are separated from a detached group of the Cumbrian Mountains, which occupies the western extremity of the county. Numerous branch ridges and groups of hills extend in various directions including many forests, fells, and crags, aeparate1 b7 valleys, drained by numerous streams, and presenting varieties of picturesque scenery.
The western extremity of the county isoccupied by part of another group of the Cumbrian Mountains divided into two party by the valley of Great Langdale. Langdale Pikes, Silver How, and Loughrigg Fell are between Grasmere and Great Langdale; and Bow Fell (2911 feet high), on the border of Westmorland and Cumberland, and Wray Nose, or V?rynoews, form the western termination of the valleys of Great and Little Langdale, which are separated from each other by a ridge called Lingmire. The two lakes of Grasmere end Rydal Water form the Itothay, which flows into the Windermere.
Geologically the county may be regarded as consisting of three parts. The slate rocks of the Cumbrian Mountain group form the first part or division; ths formations of the great carboniferous and mountain limestone series of the north of England, of which forma tions the Pennine Chain forms the western outcrop, constitute the second part or division; and the new red-sandstone of the Valley of the Eden the third.
If a line be drawn in a south-easterly direction from the foot of Ulleswater, passing a little to the south-west of Shap and Orton, and thence to Ravenstanedale, at that place bending to the south till it reaches the border of the county at the point where the road from Sedbergh to Kirkby Stephen enters it ; and if another line be drawn nearly at right angles to the former, commencing at Shap Wells. passing by the south side of Wardale Crags, and crossing the
Valley of Long Sleddele at the hamlet of Little London, the Valley of Kentmere near the Hall, and the Valley of Trontbeck a little above Town Head, and thence, skirting the southern flack of Wanefell, to Pool Wyke, near the north-west angle of Windermere, the whole county will be divided into three Irregular and unequal districts, each marked by peenlisr geological features. We shall consider them in the following order: 1. The green-slate and porphyry of the north-western district 2. The upper slates of the south-east 8. The carboniferous rocks of the northeast, and the new red sandatone of the basin of the Eden.
1. Oran-524k and Porphyry.—This, the middle term of the series into which the Cumbrian slates have been divided, and overlying the lowest member of that series In tho adjoining county (the Skiddaw slate of Sedgwick), occupies the whole of the north-western portion of the county, and is bounded on the south by the range of a series of overlying beds of calcareous slates (Coniston limestone, &c.), and on the north-east by the carboniferous rocks. It comprehends two dis tinct classes of rocks, igneous and aqueous, yet so blended and inter jected, that they must be considered as the effects of two distinct causes acting together and continued daring a lengthened geological period. The igneous rocks include almost every variety of feletone and felstone-porphyry, occasionally pluming Into groseusteue: they more rarely put on a columnar form like that of basalt. The aqueous rocks aro composed of quartz in an extremely fine state of comminution, and obtain their typical oolour from earthy chlorite derived from the Plutonic silts. All these rocks have in a greater or leas degree a slaty structure, and from them the finest roofing-elates are quarried. The rocks of this division rise Into the highest and most rugged peaks of the whole lake district, constituting the main ridge of the mountains west of High-street, those between Grasmere and Great Langdale, &c. The prevailing strike of the rocks Is north-east, and they dip at a high angle to the south-east. Garnets are found,in some abundance in the brecciated rocks of this division, and agates and other minerals occur in the cellular Plutonic silts. No organic remains have been discovered in any part of the group. Metallic veins occur in some places ; amongst others, a lead-mine is worked south-west of Ulleswater.