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On the Drift of the North of England

1867; Geological Society of London; Volume: 23; Issue: 1-2 Linguagem: Inglês

10.1144/gsl.jgs.1867.023.01-02.13

2058-105X

J.P. Curry,

Abstract T he Drift under consideration is stated to occupy certain slopes from the following mountain-eminences, namely:—Skiddaw, Saddle-back, Helvellyn, Fairfield, Harter Fell, and Shap Fell, situated in and bordering the Lake-district; and Tebay Fell, Langdale Fell, Wild Boar Fell, and Kaber Fell, ranging in a curve to the south end of the Stainmore ridge on the Pennine chain; also the series of hills northward along this chain. The author gives a geological sketch of the district, and points out that the general prevailing direction in which the drift has been carried has been from the north-west to the south-east, though much modified by the configuration of the land. He also states that from the north-western part of the Cumbrian group of mountains it has been carried, in the one case, across the slopes of the western and southern sides of the Lake-district, thence southward along the western front of the hills ranging into Derbyshire, and in the other case along the route under consideration. On the commencing part of this route the principal rocks which have yielded materials for the Drift are the Skiddaw slates, the green slates and porphyries, and the Carrock Fell and the Caldew granites. It is the waste from the granites, the green slates, and the porphyries which serves to identify and characterize the Drift on the more distant parts of its course on the Pennine chain. The waste from the various rocks of this northern area appears in the direction of Berrier, Greystoke, and Penrith. Large boulders of them are met with in the railway-excavations between Penrith and Keswick, and they Continue to the north-eastern flank of Great Dod. The Shap Fell granitic boulders are spread to the south-east of Wasdale Beck, and are probably continued in that direction across the country-side down to Tebay. Their occurrence continues for a mile or so to the east of Orton. Boulders of it lie on the western declivity from the Stainmore ridge. Among such may be noticed those at and near the following places, namely Kaber, Brough Sowerby, Church Brough, and Broughtown. They occur sparingly on both sides of the Argill Beck. Down the eastern slope of the Pennine chain, near Mickleton, and southward over the mountain-ridge into Balderdale, pebbles of indurated Silurian rock are traceable among the superficial accumulations. Lower down the valley of the Tees, Shap Fell granite and green slates and porphyry occur. The author then offers some explanations to account for the absence of detritus from the Shap Fell granite over the sloping area of the south side of the Lune, ranging between Tebay Fell on the west, and Ravenstonedale Common on the east; and proceeds to notice the occurrence of Drift northward along the western slope of the Pennine chain. From the neighbourhood of Brough Sowerby and Broughtown, down the east side of the Eden, as far as Appleby and Murton, the superficial accumulations are of a local character, being chiefly derived from the Permian rocks and from those in the bold escarpment contiguously situated on the east. Some Shap Fell granitic boulders are met with between Appleby and Dufton, and others near the base of Dufton Pike. In the vicinity of Melmerby the Drift is of a mixed nature, and continues so along its range by Gamblesby, Renwick, Croglin, and Newbiggin to Castle Carrock. The range of the Drift thus pointed out may be regarded as closely approximating its upper limit; but on the brow of the mountain, in the neighbourhood of Castle Carrock, the Drift-margin is a little above this place. From the neighbourhood of Castle Carrock, across the north end of the Pennine chain, the upper reach of the Drift corresponds pretty closely with the several collieries on the north side of the Ninety-fathom Dyke, but extends a little further to the south in the valleys of the Tyne, the Allen, and the Devil's Water. On the Tyne valley it is found to occur about half a mile below Slaggyford; in the Allen, some two and a half miles above Allen Town; and in that of the Devil's Water, a little below Lillswood. On passing somewhat direct from Midgeholme pit to Rose Hill, the Drift is seen to lie on the southern and northern sides of the mountain nearly up to its summit. To the west of a line between the last-mentioned places the drift-materials have much of a water-worn character. Small oval-shaped hills made up of these materials are very prevalent on this area, and more particularly so near the river Irthing. From the same line eastward to the Tyne the Drift occurs very abundantly. The tributaries on the west side of the Tyne, between Hartley Burn colliery and Haltwhistle, cut deep into it and expose some good sections. There is a very fine section directly down from this colliery, on the south-east side of the Blackburn, opposite Low Mill House. In the mass here presented are granites, green slates, porphyry, basalt, Mountain-limestone, shale, New Red sandstone, and some pieces of quartz. All these various rocks are confusedly mixed in a firm clay. The clay is of a reddish-brown colour and rather sandy below; but higher up it is more of a greyish blue and somewhat finer in texture. The granite occurs in small pieces, some of which are angular, and others rounded. The green slates, porphyry, and basalt are generally much rounded, and occur as pebbles and small boulders. There are some blocks of considerable size interspersed. The green slates and porphyry are very plentiful here. The blocks of Carboniferous Limestone are not much rounded, but are striated. The shale occurs in small thin pieces. Some of the fragments of New Red sandstone are angular, and others rather rounded. The clay appears to be more sandy as it increases in redness. About halfway between the Tyne and the Allen, from an elevation corresponding with the top of the Coal-formation, the Drift spreads somewhat thinly down the side of the valley to the river. The driftstones can be seen on the road down Plainmellar Common. Near Plainmellar are some granitic boulders, probably of the Criffle Fell granite. At Allen Town, on the east side of the water, the drift consists of a stiffish and rather blue clay, in some parts inclining to red, interspersed with angular sandstone very abundantly, and some Carboniferous Limestone, with a good deal of shale-fragments, also green slates and porphyry, and some portions of New Red sandstone. This heterogeneous mass has a thickness of 80 feet, and is overlain by sand and shingle, which probably averages 12 feet. A mile or so further up the Allen, but on the west side of the water, is another good section, which shows a blue clay interspersed with angular fragments of sandstone of a local character, and numerous thin pieces of shale, also some blocks of limestone rather striated. Green slates, porphyry, and basalt are very rare. The thickness of this mass is 50 feet; and it is overlain by a deposit of sandstone-pebbles 9 feet thick, above which is a stratum of water-washed sand 5 feet thick. This is again surmounted by shaly material 8 feet in thickness, thus making a face of section 72 feet in height. Again, to the east, at Langley, close to the turnpike road, the drift is exposed in a cutting of the Hexham and Allendale Railway. It is here of a dark-brown colour, with the usual kinds of pebbles and boulders. For the range of the elevation of the Drift between Devil's Water and the river Wear, the following points will afford a tolerable idea —namely, the first on the ridge about a mile to the south-west of Slealey, the second a mile up the Stanhope and Tyne Railway from Waskerley, and the third on the summit of the road leading between Dean House and Witton-le-Wear. From the first of these points the outspreading area, stretching down to the Tyne, and bounded on each side by the Devil's Water and the Derwent, is for the most part covered by Drift, in greater or smaller quantities. Fine waterworn sand prevails below Minister Acres. Green slates, porphyries, and basalt are generally disseminated among the arenaceous superficial accumulations of the adjacent country. A very considerable accumulation of Drift lies in the valley of the Tyne near Stocksfield, and can be seen with advantage on the east side of Stocksfield Burn, where it is tolerably well exposed in section. The mass thickens from the Tyne across the valley to the southern bank against which it lodges. The Drift reaches up the valley of the Derwent a little above Blanchland, and up that of the Edmondbyers Burn as far as Edmondbyers. On the ridge between this burn and Icehope Burn, it extends very little to the west of Muggleswick. From the second point the Drift covers much of the area down the south side of the Derwent. Above Waskerley, on that small area to the south-west side of the railway, it appears to be absent, but on the north-east side it occurs. It is here characterized by the scattered green slates, porphyries, &c. among the superficial accumulations. These scattered stones may be best seen on the old cart-road down the fell. The road continues down the declivity to Horseleyhope Mill, and thence by Castleside to Consett. It is on this road and adjoining parts that the various drift-stones can be advantageously observed. In the neighbourhood of Horseleyhope Mill the Drift occurs in much abundance, consisting of clay, local detritus, and detritus from rocks many of which are situated at a great distance. The clay is stiff and compact, and of a brownish colour, but varies from that to a bluish grey. It also varies in other properties, so as in some parts to become sandy. The local detritus occurs in larger proportion, and is evidently derived, in a great measure, from the Millstone-grit series. It consists chiefly of angular fragments of coarse sandstone, and small rather thin pieces of argillaceous strata. The former range from very small sizes, through a gradation, to that of large angular blocks. The far-carried detritus comprises green slates, porphyry, and basalt, which occur in the form of pebbles, boulders, and some large blocks. The fragments of granite are only small and often angular. Among these various stones may be found the representatives of most of the rocks of the Lake-district. South of Horseleyhope Mill and Cold Rowley, the Drift occupies the flank and summit of the hill, and from the latter place it spreads down to the Derwent. On this declivity it is of a sandy character. From Consett eastward it prevails rather partially on the higher grounds until we come to Whickham, where it would seem to be more regular. Boulders of Shap Fell granite lie on the bank below Whickham. Carrock Fell granite also occurs in the valley of the Derwent, with others which are evidently from Scottish localities. From the third point down the hill-side to Witton-le-Wear, there is apparently an absence of Drift. This may probably be the case on the slope to the Wear eastward. On the north side of the hill, from its summit to Dean House, it occurs in not a very marked character. Such it may likely continue to be on the declivity towards the river Browney. It is slightly traceable from the ridge south of Consett to near Lanchester. Thence to Durham it is apparently not traceable. At this place much sand occurs. Among this there seems to be no granite or other stones to mark it as the true drift. These sandy accumulations at Durham, and those previously noticed, have evidently resulted from the denudation of the Millstone-grit. From Witton-le-Wear bridge, following the road by West Auckland to near Staindrop, no indications of the Drift are met with. At and near this place a few stray boulders of Shap Fell granite occur. There are others in the neighbourhood of Barnard Castle. Thus from a little north of Staindrop to Barnard Castle may probably be near the range of the Drift-elevation on the north side of the Tees. But on the south side of the river, Shap Fell granite occurs at Lartington, and is likely to be found strewn down from here to Barnard Castle. Thence down the north side of the river to Darlington the miscellaneous character of the Drift prevails. Boulders of Shap Fell granite are observable near Winston. In the North Street at Darlington lies the well-known granite Shap Fell boulder. Others of the same kind occur at Cockerton. On the road between Cockerton and West Auckland there seems to be an absence of the true Drift. Granite from Shap Fell and green slate and porphyry from the Lake-district make up a part of the drift-materials on the Tees. From what has been previously stated respecting the Drift on the Stainmore ridge and on the eastern slope to Lartington, it will now appear obvious that it has been carried over the ridge and down to the mouth of the Tees. At one time it may have lain on the Stainmore ridge in considerable quantity. From the Tees the erratic blocks of Shap Fell granite have found their way along the eastern declivity of the Pennine chain as far as the mouth of the Humber.