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although the beds in our country so designated cannot be correlated in time with exactness with the rocks distinguished by those names on the Continent. In the same way, where the Oxford and Kimeridge clays come together without the intervention of the Coral Rag series, and without unconformability, we cannot perhaps identify the exact equivalent of the Coral Rag, and cannot do better than use the purely lithological terms.
New RED SANDSTONE.
The Bunter (variegated) Sandstone of Germany was first identified in England in 1826 by Sedgwick.
The general divisions of the Bunter beds are thus given by Professor Hull :
Upper Mottled Sandstone. -Soft, bright, red, and varie
gated sandstone. Pebble Beds or Conglomerate.—Harder reddish brown
sandstones, with quartzose pebbles, passing into con
glomerate; with a base of calcareous breccia. Lower Mottled Sandstone.Soft, bright, red, and varie
gated sandstone, showing much false bedding. The Lower Mottled Sandstone attains a thickness of about 650 feet at Bridgenorth ; in Cheshire it is 400 feet; at St. Helen's Junction it is about 250 feet; and in South Staffordshire 200 feet.
The Pebble beds attain a thickness of from 60 or 80 feet to 600 feet. They are composed chiefly of quartz, the pebbles of which (according to Mr. Aveline) are found either loosely scattered amongst unconsolidated sand, or cemented into a hard conglomerate. So gradually do they pass into
the sandstones below that there is no very definite line of separation.
The Upper Mottled Sandstone attains a thickness varying from 200 feet to as much as 700 feet at Delamere Forest.
The total thickness of the Bunter beds is estimated at 1,000 to 2,000 feet.
The Hemlock or Himlock Stone, near Nottingham, consists of the Lower Mottled Sandstone capped by the Pebble beds. In this locality the sandstone is about 80 feet thick, but further towards Nottingham it has a thickness of 100 feet.
The Vale of Clwyd is formed in the Bunter sandstone, belonging in all probability, according to Professor Hull, to the Lower Mottled Sandstone; but sections are rarely seen owing to the covering of drift. In the Bridgenorth district these beds form the fine ridges of Apley Terrace, Pendlestone Rock, Abbot's Castle Hill, and Kinver Edge.
The beds may also be studied near Market Drayton, Cannock Chase, and Sherwood Forest.'
The greater part of Nottingham is built on a coarse white sandstone, containing scattered pebbles of quartzite, &c., belonging to the conglomerate division, according to Professor Hull. The old castle stood on a cliff of the same rock. Artificial caverns have been excavated in it.
In the Liverpool district the beds are represented by reddish-brown pebbly sandstone, largely quarried for building purposes.
The Upper Red and Mottled Sandstone, both in structure and composition, appears to be the most uniform division of the Bunter. In the neighbourhood of Birkenhead, Liverpool, and Ormskirk, the lower portion of this sub-division is red, the upper yellow, and sometimes
It is owing to its poor sandy and gravelly soil that the Forest of Sherwood existed so long, the greater part being still retained as woodland or common. (Aveline.)
sufficiently hard for building purposes. It is developed at Stourport. The town of Birmingham is built principally upon it, and it is exposed near Wolverhampton.
The Bunter beds have not been identified with certainty south of Malvern, but there is a probability of their being represented in West Somerset and Devon (see p. 141). Near Malvern they are represented by 400 feet of red and white sandstones and conglomerate.
The Bunter sandstone yields a good supply of water, being in fact one of the most prolific of the water-bearing strata.
The Bunter Conglomerate of Cannock Chase has, according to Mr. Molyneux, yielded lead and copper ores.
New RED MARL.
The Keuper beds which overlie the Bunter are divided
Upper.—Red and variegated marls with beds of sandstone,
800 to 3,000 feet. Lower.—Sandstones (Waterstones') having a thickness
of 200 feet in Derbyshire and 450 feet in Lancashire. There is, however, no hard line of demarcation between the two divisions. Keuper is a provincial German term.
Lower Keuper.-- This division consists of thinly laminated micaceous sandstones and marls; also of white, brown,
1 This term was originally used by Mr. Ormerod because the surfaces of some of the beds had a watery appearance, like watered silk. The term as generally understood expresses the water-bearing qualities of the strata.
or reddish sandstone, with sometimes a base of calcareous conglomerate or breccia.
Prof. Hull has given the following general section of their succession :
Waterstones (passage beds into the Red Marl).-Brownish
laminated micaceous sandstones and flags, rippled, with
beds of sandy marl. Building-stones.-Fine-grained light-red, brown, yellow,
or white freestones, regularly bedded, with occasional beds of red marl, producing the best building-stone of
this formation. Basement beds.-Coarse, irregularly-bedded sandstones,
calcareous breccia and conglomerate, with bands of marl and mottled calcareous beds similar to the “Cornstones' of the Old Red Sandstone.
Many foot-prints of Labyrinthodonts (Cheirotherium) have been discovered in the Keuper Sandstones, and particularly in Cheshire. Perhaps the quarries at Storeton Hill, on the penins'ıla of Wirral, are the richest in these traces of ancient life.
The beds have been largely quarried for building purposes at Ombersiey and Hadley.
In the neighbourhood of Pattingham and Tattenball the baseinent beds have been burnt for lime.
The beds are exposed near Bromsgrove, Kidderminster, and Bridgenorth, near Wolverhampton, Rugeley, Colwich, Eccleshall, Hawkstone Hills, at Overton Sear, and in the Peckforton Hills, Cheshire. They are also seen at Delamere Forest (450 feet), Storeton Hill, in East Warwickshire, at Ashby-de-la-Zouch and Alton in Staffordshire, also in Derbyshire and Nottinghamshire.
Among the local stones may be mentioned the Bank Delf Stone of Bank Quarry near Melling; the Runcorn stone;
the Tinkersdale stone of Grinshill, Shrewsbury; the Durme Stone ? of Drayton Basset, Tamworth ; and the Kingwood Stone in the neighbourhood of Codsall.
The Lower Keuper sandstones of Alderley Edge have yielded much copper-ore.
Upper Keuper.—The uppermost deposit of the Trias consists very often of Red Marl.
It comprises a series of red and variegated marls, the red colour preponderating, and the beds being mottled with spots and streaks of a grey or green hue.
In the upper part the marl is softer and generally without distinct lines of stratification, and it is usually much broken up and fissured by cracks or joints and miniature faults. The rock presents a rubbly appearance, and is often separated into small masses of a cuboidal or rhombic form. Interstratified with the marl there often occur beds of hard red and sometimes grey or cream-coloured marl, and sandstone.
The presence of carbonate of lime does not appear to be invariable, but the amount is sometimes so trifling as not to be detected by the application of hydrochloric acid.
These red and variegated marls were first identified with the Keuper of Germany by Sedgwick.
Beds of sandstone occasionally occur in the Red Marl. In the neighbourhood of Tewkesbury there is a bed of white sandstone 20 to 30 feet in thickness in the Red Marl.
In the Upper Keuper Sandstones near Taunton, Mr. C. Moore has discovered remains of Estheriu minuta, fish, Labyrinthodon, &c.
Prof. T. R. Jones and Mr. Parker have described a series of Foraminifera from the Red Marl series at Chellaston near Derby.
The Keuper Marl forms fine rich meadow-land ; the soil