Knoll, south of Kinderlow End, about which there is, we think, little doubt.

The sameness of the Shale Grit plateau is again a little broken on its eastern side by two small outliers of Kinder Scout Grit, one on Crook Hill and the other on Win Hill. The first, though the lower of the two, is very strongly marked by the rugged crags of its escarpment; these give very clearly the base of the Kinder Scout bed, but the line of the top of the Shale Grit is almost wholly conjectural. It is delightful to see how clearly the Kinder Grit has stamped its character on this little outlier; the first glance at it even from a distance is enough to show one, who has got to know the look of the rock, what the capping to the hill is made of.

Win Hill, which rises, a sharp conical peak, to the height of 1,575 feet above the sea, is also capped by a small patch of Kinder Grit. The rock is probably faulted at the west end, and neither its base nor the top of the Shale Grit can be fixed with any certainty, on account of the large quantity of fallen rock that strews the flank of the hill.

(2.) Shale Grit round the Peak.

Surrounding the Peak on all sides, and bounded on the west, east, and north by the escarpments of the Lower Kinder Scout Grit, and on the south by the Mountain Limestone, is a ring of country mainly occupied by Shale Grit. It bears the general look of a plateau, about 500 feet lower than the table-land of the Peak itself, deeply channelled, and in places almost wholly obliterated, by brook-courses and river-valleys. The character is best preserved on the west, north, and east; on the south the valley of Edale, over which the plateau must once have stretched in an unbroken flat, cuts off from the main mass the ridge of Rushup Edge and the outlier of Lose Hill; while towards the south-east the valley of the Derwent in the same way severs the high flat ground of Abney Moors, which must originally have formed part of the general plateau.

In describing this broad spread of rock, we will start from Chapel-enle-Frith and work northwards; then turn to the east till we reach the valley of the Derwent, which we will follow down to Bamford, and finish with the valleys of Edale and Castleton.

The structure of the country immediately to the north-east of Chapel-en-leFrith is far from clear, and the lines on the map are many of them only approximately true. A fault, passing near the church and running northwest and south-east, was seen in a quarry by the road side between Blackbrook and Barmoor Clough, and it seems to be the cause of the sudden change of dip from N.N.W. to S. which is seen in the section up Ashbourne Lane.

Another fault is seen behind the farm house Plumpton, and in a quarry west of Bagshaw. And there seemed reason to believe that a lode near the place called Coal Pit" on the map is a small fault, which runs on towards Bow. den Head.

A long tongue of the Shale Grit runs out along Rushup Edge and Cowbarn to Lord's Seat. The rock is best seen in a large quarry on the Castleton Road, a little beyond Slack Hall; it is massive but not coarse. A band of shale, probably not more than 20 feet thick, is very constant hereabouts in the grit; it may be traced by the little terrace made by its outcrop on the hill sides, and could it have been carried on with certainty, it would have divided the bed into an Upper and a Lower Shale Grit. But further north the shale-beds became so numerous and irregular that we could not fix on any that could safely be looked upon as the equivalent of this bed; and even if this difficulty had been got over at any one point, we should never have felt safe that we did not in

our further progress occasionally jump from one shale band to another, so the attempt was given up.

There must be a fault between the Shale Grit of Bolt Edge and the limestone, as there is not room enough for the Yoredale Beds between the two. Some indications of this fault were seen in the valley opposite the Ebbing and Flowing Well.

It seems likely also that a fault runs between the base of Rushup Edge and the limestone boundary, for the following reasons. There are some old shafts on the Odin Lode in a plantation three quarters of a mile E. by S. from the Trigonometrical Station on Lord's Seat, which must have gone down to the limestone, and there does not seem room enough to get in the whole of the Yoredale Rocks between the base of the Shale Grit on Rushup Edge and the bottom of these shafts. The Odin Lode itself is not this fault, for both its walls are limestone, but most likely the lode and fault are so close together that they cannot be laid down separately on the map. Fig. 12 will explain this.

A little to the north of Chapel-en-le-Frith there is a fault ranging E.N.E.; between this fault and another through South Head the structure of the low country is very obscure. The dips are very irregular, and perhaps some of the faults which are found on the north run down to hereabouts. The two valleys of the Roych and Roych Tor give fine sections of the Shale Grit, showing between four and five hundred feet of sandstone with shale beds.

In the western part of the plateau of Shale Grit, between the Peak and the western escarpment of the Kinder Scout Grit, we find a number of faults having a general north and south trend. Along this line the beds, which on the crest of the saddle are all but flat, begin to bend over sharply to the western dip, and it was most likely this wrench which brought about the foldings and breaks in the rocks.

We will now trace out the main line of disturbance. Contortions may be seen in all the brooks along this line from South Head farm to Kinder Head; at the former they show merely sharp rolls, and the fault is perhaps just dying out; at the latter the beds are on end, and violently contorted for several hundred yards. The section in William's Clough, sketched below, gives us the exact place of the break.

1. Sandstone and shale. 2. Thin, hard sandstones and sandy shales.

S.W.

x Position of the fault.

On the same line we again find broken beds in Long Grain, two small faults in Bakestone Delph Clough, heds on end in Shelf Brook, and very high dips in the stream through Lightside Plantation. We have, however, scarcely evidence enough to justify us in assuming a fault along the whole of this line, but the beds are certainly faulted both at its northern and southern ends.

The other faults branching from this have been drawn as well as circumstances would allow. They for the most part only bring one part of the Shale Grit against another part, and therefore cannot be traced with certainty.

Turning now to the east, we enter a tract nine miles long, with an average breadth of four miles, wholly occupied by Shale Grit; it includes Glossop, Alport, Ronksley and Derwent Moors, and the district called the Woodlands. The plateau formed by the rock is deeply cut into by many brooks, any one of which will be found to give an admirable section of the measures; but one will serve as a type for all, and there is nothing of special interest except in the valleys of the Alport, Ashop, and Derwent.

The river Alport runs over Shale Grit, yielding excellent sections, till about three quarters of a mile above Alport Castles, where it cuts down to the beds taken to be the Yoredale Sandstones. In these beds, though sandstones occur, yet the bulk of the measures is shale, and immediately the river enters upon them its eastern bank begins to be covered with huge landslips formed of masses of the Shale Grit which have slid down from the hill top above. They strew the hill-side in vast numbers for the whole distance that the river runs through the shale measures, and immediately cease when it again enters the Shale Grit.

The most striking of these landslips is Alport Tower, of which a sketch is given in Fig. 10. In the hill-side is a large opening, with vertical faces, looking exactly like a quarry, 150 feet high and 28 chains long. The mass of sandstone that once filled this hollow has slipped down into the valley, and breaking up has formed a series of under-cliffs with steep, scarped edges, the highest of

which is peaked in shape, and forms "The Tower." The slipped mass is 12 chains across at its broadest part: many of the bummocks of sandstone are scarcely broken at all by their fall, and still show the same dip and bedding as the unslipped mass above, of which they once formed a part. Below this, quite down to the river bank, the side of the valley is covered by older landslips, the features of which are somewhat hidden by trees, and have lost some of their sharpness from atmospheric wear, but which still have an unmistakeable stamp about them. The spot is well worth a visit, both by the lover of scenery, for it is strange and fanciful, and by the geologist who wishes to study the effects of atmospheric action in wearing away a country.

Here

Owing to these slips we get few sections till we reach Alport Bridge. abouts and for some little way up the Ashop we find the Shale Grit passing downwards into a mass of dark shale with thinly bedded sandstones, which we look upon as the equivalents of the Yoredale Sandstones: it is, however, all but impossible to draw a line that shall be worth much between them and the Shale Grit. Below these beds are black shales with nodules of limestone containing Goniatites, which we place in the bottom group of the Yoredale Rocks;* on this supposition the Yoredale Sandstones will here have a very small thickness. The black shales may be seen in the Alport a little above the bridge, and in a heading that has been driven into them in search of coal (!) between the 14th and 15th milestones on the turnpike road. Some hundreds of pounds were thrown away here under the direction of a "practical miner" who “liked the measures," and gave it as an opinion beyond question that "coal could not be far off."

The river continues to flow over shale measures for about a mile and a half below the bridge, where the Shale Grit is again brought down to its level on the south bank by a steep south-easterly dip. The section is very pretty, the beds rearing up at angles of 30° and 40°, and the harder standing out in reefs across the water. On the north side of the valley the exact place of the base of the rock cannot be fixed, on account of the landslips, but it is certainly far above the river, and there must be either a very sharp roll over of the beds or a fault such as is drawn on the map. Horizontal Section, Sheet 69, of the Geological Survey, which crosses this spot, will explain the lie of the rock.

Hence down to its junction with the Derwent the river flows through the Shale Grit.

The river Derwent rises below the northern escarpment of the Kinder Scout Grit and flows through the Shale Grit down to Yorkshire Bridge. For the whole of this distance admirable sections are given by the river and its feeders, the rock being perhaps best shown in Abbey Brook, which gives the following

section.

Section of the Shale Grit given by Abbey Brook.

Shales. Grey sandy shale with tilestone in the lower part.
Flaggy sandstone

Grey sandy shale and tilestone

Approximate thickness in feet.

Coarse massive sandstone and conglomerate

Flaggy sandstone and shale

Bed of coarse conglomerate

}

Shale

Shale, sandstone, and tilestone

80

20

80

Thick mass of sandstone with scarcely any shale,
probably quite

200

Though the number and thickness of the shale beds vary very much from place to place, the general character of the rock is everywhere pretty much the same, and is sufficiently shown by the above section. We must, however, call attention to the excessively disturbed state of the beds along this part of the Derwent valley. We find contortions here and there in the upper part of the river, one of which is figured in Fig. 11, and is as odd a piece of bedding as could well be found anywhere. Between B and A the dip is N. W. from 10° to 20°; at A the strike changes through a right angle almost all at once, and the beds dip E.N.E. at 70°, the angle lessening rapidly to the north-east; at C the strike gradually changes to N. and S. and the dip becomes more gentle.

* The following fossils from these beds have been determined by Mr. Etheridge: Posidonomya Gibsoni, Goniatites Listeri, G. reticulatus, G. striatus, G. sphæricus.

Above the junction of the Westend river the beds are not much disturbed, but from that point to Derwent Hall they are violently bent and folded into a number of very sharp anticlinals, which run sometimes a little west and sometimes a little east of north and south. Now it will be recollected that on the other side of the great anticlinal the beds were bent over with a sharp

and sudden change towards the western dip, and along this line we had a belt of faulted ground (p. 41). Here in like manner we meet with disturbances along the line where the easterly dip comes on; but here, perhaps because the change of dip is much more gradual than on the other side, the strain has not been so great and has been able to do no more than bend and fold the rocks into sharp anticlinals, without going so far as actually to break and fault them.

A fault, of which we shall learn more by-and-by, crosses at Derwent Hall, and throws the beds into extraordinary confusion. Another fault crosses about half a mile lower down, and between these faults the rock is as it were pinched up and squeezed into several sharp anticlinal folds, whose axes range approximately parallel to the faults.

The river flows over the Shale Grit till below Yorkshire Bridge, when it cuts down to an underlying mass of black shale, most likely brought up by a small fault.

We will now pass to the south side of the Peak. Here the base of the Shale Grit is found running roughly along the ridge from Lord's Seat by Mam Tor to Lose Hill, and this line may be looked upon as the southern boundary of the plateau of that rock which we have spoken of as surrounding the Peak, for beyond it the rise is steadily to the south, and lower and lower beds come out, till at Castleton we find ourselves on the Mountain Limestone. Instead of having however an unbroken spread of Shale Grit, as was the case on the north, this southern plateau has been cut into and in great part carried away by denudation, and along the middle of it runs a broad and deep hollow, the rich valley of Edale, the geology of which we will now notice.

An anticlinal line ranges along the north flank of the valley, and on the north side of it the Yoredale group is brought out to-day by the southerly rise of the beds, and is well shown in sections which have been already described. On the south of the anticlinal line there are few sections except along the river Noe.

About at right angles to this anticlinal is another running nearly through Edale Chapel and Mam Tor: by this a dome-shaped mass of beds belonging to the lowest Yoredale division is brought up in the middle of the valley, and the Yoredale Sandstones of Mam Tor are