whole will be about 100 feet thick. There was no sign of alteration in the underlying limestones at their junction with the toadstone.

It must be allowed that so rapid a thinning out of the toadstone as is required by the above explanation is somewhat startling. After a careful examination of the ground, however, we could come to no other conclusion. We must here for a moment leave the railway, and note the section seen as we go down into the dale; it gives us

Toadstone. No. 4.

Massive white limestone. 150 feet about. Upper part of No. 5.
Toadstone.

Of the bottom bed we just see the top of a dome-shaped mass sticking out in the bottom of the dale.

Returning to the railway we find the massive white limestone, No. 5, lying all but flat or rolling gently, in all the cuttings up to the entrance of Chee Tor Tunnel. At the beginning of this cutting the beds rear up all at once at an angle of 40°, and at the mouth of the tunnel the dip has increased to 60°, and a bed of toadstone No. 6 breaks out. This will at first be of course taken to be the same as the bed already mentioned as peeping up in the bottom of Miller's Dale; but that bed lay only 150 feet below the top of No. 5, while in the cutting alone, which we are now looking at, there are 320 feet shown of solid limestone above No. 6 toadstone. Either, then, No. 5 has more than doubled in thickness between here and Miller's Dale, or the Miller's Dale toadstone thins out to the west, and No. 6 is a distinct and lower bed. We think the latter supposition more likely.

It is very difficult to make out exactly how the toadstone No. 6 behaves, on account of the disturbed state of the beds, but it seemed most likely that it flattens very suddenly and is the same bed as that which crops out a little before reaching the steep descent to Chee Tor: in this case its thickness will be between 10 and 20 feet.

The toadstone No. 6 rests on a mass between 500 and 600 feet thick, No. 7. gives a fine section of part of this rock. and shows three beds of limestone, the upon 200 feet thick.

of very thickly bedded white limestone The magnificent precipice of Chee Tor The cliff is said to be 300 feet high, lowest of which is most likely close

Below the Chee Tor rock are limestones by no means so thickly bedded, and often split up by irregular shale partings into nodular masses; they are marked No. 8.

The beds marked No. 9 are the lowest shown in the section, and consist of a number of limestone beds of various thicknesses; they form a long flat dome reaching as far as the Pig Tor tunnel. A very odd rock was noticed at one spot, at first glance exactly like a sandstone, but on examination the grains were seen to be rhombohedrons of calc-spar loosely cemented together.

Along the long flat top of the saddle the beds roll a great deal, but at Pig Tor a steady dip sets in to the west; we cross the westerly outcrop of Nos. 8 and 7, and at the mouth of the tunnel nearest to Buxton find a toadstone, which agrees well with No. 6, resting on the top of the latter. The bed is about 20 feet thick, solid, rather concretionary, vesicular or amygdaloidal, dark olive green colour, but weathering red along the joints. The upper surface of the underlying limestone was very much waterworn.* For the most part there was no sign of alteration at the junction; but here and there the rock had a baked look for a depth of two or three inches.

The toadstone is again seen at the western mouth of the tunnel; it is here contorted and very much broken. It seems, however, to be overlaid by a massive white limestone, which agrees with No. 5, and which may be traced till about 250 yards before the bridge over the Fairfield road, where it begins to be much shattered, and about 50 yards farther on it is faulted against black Yoredale shales, as shown in the figure below.

* This may be because the top of the limestone was subjected to erosion before the toadstone was ejected; but it is quite as likely that the furrows and hollows on the surface of the limestone have been produced by carbonated water circulating along the junction of the beds, long after the formation of both limestone and toadstone.

1. Thickly bedded limestone, much shattered near the fault.
2. Black shale.
A C. Horizontal line.

3. Limestone.

A B. Line of railway.

4. Black shale.
xx Fault.

Here, then, our section is broken off, but in the Doveholes brook we see the topmost cherty beds of the limestones passing regularly below the Yoredale shales. If our identifications are correct, it follows from this that there is some other fault yet undiscovered, or that the equivalents of Nos. 1, 2, and 3 are much thinner on this side the anticlinal than we found them to be on the east side.

Section at Doveholes.

A

The above section is drawn up from personal observations, and from information from quarrymen and others, the thicknesses being from Horizontal section, Sheet 70.

The Toadstone No. 3 was seen in a quarry a little south-east of the Bull Ring. It is a crumbly bed, pale-grey with green specks, and contains pebbles of limestone, one of which was seen as big as a man's fist. The upper surface of No. 4 was very much furrowed and worn into pot-holes, perhaps by the action of water as previously noted.

Section near Stoney Middleton.

There is a section worth notice in the upper part of the limestone given by large quarries at the bottom of Combs Dale near Stoney Middleton. The beds are rather irregular, and the two following sections were measured in different parts of the quarry :~

Thin clay partings are not uncommon in the limestone, but we have in one other instance only (p. 23) noticed any traces of coal in this rock. These little beds seem to show that the formation of coal, which went on on a small scale during the Yoredale and Millstone Grit periods, and after showing a marked increase in the Ganister beds reached its fullest development during the time of the Middle Coal-Measures, began here and there even so far back as the end of the Limestone epoch.

Matlock.

The following section of the measures hereabouts was given us by an old miner :

Section at Matlock.

1. Limestone and chert

2. Massive limestone

3. Shale with Ironstone nodules and Calamites*

4. Toadstone

5. Massive white limestone, with three thin partings

or way boards" of clay or shale

6. Toadstone

7. Limestone

8. Toadstone

In his "General View of the Agriculture and Minerals of Derbyshire" (page 129), Farey gives the following section of these beds :

Section at Matlock. After Farey.

:

* There are some very fine specimens in the High Tor Cavern, which we were assured came from this bed.

The two following sections are given in Pilkington's "View of the present State of Derbyshire," pp. 51 and 55 :

66

ft.

150

74

48

1

90

'Blackstone," said to have been proved to be 240 feet at a mine called "Porter," two miles south of Snitterton, and found to be 90 feet two miles south-west of Snitterton.

Limestone, thickness not ascertained.

The railway-cutting immediately to the north of Matlock Bath Station shows the upper beds and gives the following section :

Section in the Railway-cutting at Matlock Bath Station.

4. Toadstone, rudely bedded and somewhat concretionary:
mostly solid, but here and there, and especially in the
bottom three feet, soft and crumbly. Dirty olive-green
colour, with red stains

5. Thickly bedded limestone. No sign of alteration at the
junction with the toadstone.

No. 3 was not present here, but the miner assured me that it was found in the sinkings, and showed me some Calamites which he said were from this bed.

De la Beche* records that a thin bed of impure coal occurs in the higher part of the limestone series near Matlock Bath. It was cut while driving the tunnel through the High Tor, and was to be well seen, dipping rapidly with the other beds, in the drift cut into the cavernous mine, part of which is shown by the name of Rutland Cavern, at the Heights of Abraham. The coal rests on a true underclay of the CoalMeasure kind.

* The Geological Observer, 2nd Ed. 1853, p. 560, and foot-note.

The same group of beds is shown in quarries on the opposite side of the river, and the toadstone No. 6 has been proved in a heading driven into the rock at the foot of the High Tor.

Wirksworth.

The neighbourhood of Wirksworth is interesting as showing thick beds of magnesian limestone interbedded with the usual blue limestones of this formation. The general section noted hereabouts was as follows::

The upper toadstone may be seen in a cutting of the High Peak Railway, about a mile north-west of Wirksworth.

The magnesian limestone runs up into masses with a rudely castellated and sometimes spiry outline, as at Harboro' Rock, about two miles west of Wirksworth.

The lower toadstone at Hopton is a very coarse brecciated ash, with beds of dolerite.

The few sections just described, which are all we have been able under the circumstances already mentioned to obtain, are drawn out to scale in Fig. 3, p. 25. In the present state of our knowledge it will be useless to speculate on the possible identities of the beds; but it looks as if the toadstone bed No. 4. Sect. I., No. 5. Sect. II., No. 6. Sects. III. and V., No. 3. Sect. VI., and No. 7. Sect. VIII., though very changeable in thickness, keeps pretty nearly a constant horizon throughout; this will be the "Second Toadstone" of Farey and the old geologists. The exact horizon of the beds in the High Rake Mine is doubtful; but, if we have placed them correctly, the agreement between this section and the Crich beds, even in such small matters as the "way boards" of clay, is worth notice. Between the other details of the measures little or no correspondence can be traced.

*The thicknesses are from Horizontal Section of the Geol. Survey, Sheet 60.