CHAPTER I.ENGLAND—GENERAL SKETCH.
Differing as England does in people, manners, language, laws, and institutions from Scotland, a still greater difference will be found to exist in the physical structure, the mineral qualities, the organic remains, and in all the other phenomena of her geological development. In the ascending series of rocks, Scotland furnishes only a few steps of the building—the lower courses of a gigantic pyramid; across the borders, strata upon strata follow each other in regular gradation, until they attain their apex of elevation in the center of the capital. Another distinction exists in the quantity and extent of those rocks which are common to both countries. All the primary, transition, and igneous formations are more abundant in the northern division of the island, constituting nearly three-fourths of its surface, while in the southern division they do not amount to a fiftieth part; but, on the other hand, the secondary and tertiary formations, which in Scotland are scarcely recognized, or only found in patches, form in England about two-thirds of its superficial area. Hence, on English ground, a new interest begins as a totally new series of mineral strata rises into view, and all charged with types and families of creatures of equally new and marvelous organization.
The new series of rocks to be described, are termed the Permian, triassic, oolitic, cretaceous, and tertiary systems. Some ofthese deposits are of vast thickness and extent. They all abound in fossils, some in the greatest profusion, others only in the rarest and most remarkable types. In consequence of these accumulations, England, as compared with her sister kingdom, may be described as the full organic form in bones, muscles, and fleshy appendages, plump and rounded all over, where one sees little of the framework or internal ossification. The great masses are so covered over, the ribs and members are so silted up, that the ridges and hills of the country, save on the outskirts, dwindle into insignificance. Every original depression has been concealed, new increments of matter are everywhere added, layer upon layer superinduced, until the older fabric is nearly obliterated, or only at wide intervals observed to rise above the surface. Scotland exhibits the huge trunk, stripped and laid bare; every yielding thing has been eroded and torn off; and little remains, except the giant skeleton, the lineamentary fragments of the primeval world.
What is common to the two countries, among the primary and crystalline rocks, occupies the whole western line of coast. The eastern shores of Ireland, correspond in mineralogical character with the opposite shores of Scotland, England, and Wales, where a great silurian belt covers, almost continuously, both lines of coast. These districts have thus all a common origin, are all of the same geological epoch, and were probably at one period more united than appearances now indicate. The Cumbrian group is isolated from the other portions of the system, and, as described by Professor Sedgwick, comprehends the lowest fossiliferous beds in the island, or perhaps as yet known in the crust of the globe. The elaborate work of Sir R. I. Murchison on “The Silurian System,” has made every one acquainted with the extensive deposits in Wales and Cornwall, in which the divisions of the system are fully pointed out, their fossil contents amply detailed, and their relations to analogous deposits in other parts of the world satisfactorily demonstrated. Through all these regions, therefore, we are again carried back among the earlier records already noticed. Coincident with the same are the old red sandstone deposits which stretch along the base of the more highly-inclined silurians, covering the greater portion of Herefordshire and Devonshire; and here, as in Scotland, the sandstones and conglomerates are immediatelysucceeded by the rich treasures of the carboniferous age. In the rocks of the three families lie, in profuse abundance, the organic remains of the epochs which produced them—cast like wreck among the silts and sands now hardened and upheaved into mountains—the peaks of Skiddaw and Snowdon, of Plinlimmon and Helvellyn, once the beaches or floors of our ancient seas.
The Cumberland group of mountains, with its varied scenery and lakes, is surrounded with the carboniferous rocks—as bright and lovely a picture, set in a framework of jet or ebony, as the mind can contemplate. The greatscar, or mountain limestone, constitutes the base of the coal series, resting on the old red conglomerate. This calcareous deposit is of vast thickness, range, and extent—a concrete mass of animal remains of five or six hundred feet. It presents the outline of a great coral reef which anciently fringed the center cluster of the lake mountains: and is still, with a few breaks, traceable along their wide and irregular circumference. The sublime gorge of Gordale, the fine gray precipices at the foot of Ingleborough, the caverns of Chapel-le-Dale and Clapham, the rocks of Kirby Londsdale Bridge, and the great white terrace of Whitbarrow, all derive their peculiar features from the effects of erosive action on this formation. Diverging from the great terminal group of the Cumbrians, the same deposit rises along the center of the district into an independent ridge, taking up the most commanding positions—the towering summit of Cross Fell on the one hand, and the celebrated High Peak of Derby on the other, with all its wondrous caves and sparkling fluor-crystals. The intermediate range of the Penine Alps, so denominated by the Romans, is chiefly composed of the formation. The caves of Kirkdale, the haunt of the British hyena and other extinct carnivora, are situated in the same limestone, which is also the repository of numerous lead mines, distinguished for their splendid metallic concretions and fluor-spars. And here, too, are rivers which are lost in its dark caverns; and that wonder of wonders, an astronomical paradox, where, from the peculiar conformation of the hills and ravines, the sun does not rise upon the inhabitants of Narrowdale, until he has passed his meridian, and, as if to repair the loss, twice sets upon their horizon in the course of every evening.
The coal-measures on the eastern side of this chain consist of the Northumberland, Durham, Yorkshire, Nottingham, and Derby fields; on the west and north, Whitehaven, Lancashire, Manchester, and North Stafford; and on the south lie the basins of Ashborne, Loughborough, Wolverhampton, and Dudley. The limestone skirts the out-crop of the metals in all these localities, and thus serves to define the relations of the several basins, and the cause of so many divisions in the field, occasioned by the net-work of coral reef with which it has been originally penetrated. The Wolverhampton basin is remarkable for the number of roots and stumps of fossil trees found “in situ;” in the Derby field the railway tunnel has exposed to view a group of sigillaria, forty in number, standing at right angles to the plane of the beds, and not more than three or four feet apart. Many of the tree fossils occupy a similar position in the Northumberland and Newcastle coal-measures, reminding us of the submerged forests of which, within the modern epoch, our sea-coasts furnish so many examples. The Newcastle coal-field embraces an area of nearly eight hundred square miles, being forty-eight miles in length by twenty-four in breadth; the depth of the shaft is about three hundred fathoms, from which are annually brought to the surface an average of six million tons of coal. Sixty thousand persons are employed in the mining operations; and fourteen hundred vessels are engaged in carrying the mineral to London and its environs. The iron trade, connected with the different English coal-fields, is upon a corresponding scale of magnitude, there being little short of a million and a half tons of the metal annually smelted and brought to the market, estimated to be worth, upon an average, twenty millions of pounds sterling, and comprising within the dimensions of this small island, as much as is exhumed by all the other nations of the globe. The Newcastle coal-measures have been singularly disturbed. A basaltic dyke, in some places eighteen yards wide, crosses the southern part of the field, throwing down the metals on one side ninety fathoms, and reducing the coal, at the distance of fifty yards, to a state of cinder. This great dyke is traceable through a course of seventy miles. As an example of the prodigious power with which these subterranean forces have acted in the district, suffice it to mention, that thelimestone which underlies the coal metals has been elevated nearly to the summit of Cross Fell, a mountain three thousand feet in height; and estimating the thickness of the formation at four thousand feet, the limestone, it will thus appear, has been raised above its original position upward of six thousand feet.
The “green rock,” or basaltic greenstone of the South Staffordshire coal-field, presents an interesting subject of geological research. The center of the formation, as also that of the eruptive agency of the tract, may be considered to be in the Rowley Hills, from which the latter diverges on all sides, setting off innumerable veins or vertical dykes, which are subdivided into smaller veins of a white color, and everywhere penetrating and altering the shales, sandstones, and coal metals. This igneous mass is more of an underground than super-surface rock, occupying an area of twenty-five square miles, and rising only into slightly-elevated and detached ridges. It corresponds, in mineral characters and position, with another extensive effusion of trap in the northern coal-fields, termed the “Whinsill.” This consists of a bed of basalt, which has been injected among the strata of the coal-measures, or, as some conjecture, has been poured over them as a cotemporaneous formation—an overflood of lava produced during the deposition of the mountain limestone group, and overlaid in turn by the succeeding series of upper strata. Nearly the entire coal-measures of the north of England have been more or less influenced by the eruption of the Whinsill, from which dykes are thrown off in every direction, accompanied by phenomena precisely similar to those exhibited in the coal districts of Scotland. In both countries the same agencies are thereby demonstrated to have been at work, originating in the same causes and producing similar effects, and doubtless cotemporaneous in their operations over these and other immense areas of the globe.
The rocks which constitute thesecondaryandtertiary divisionsin the great geological series remain to be described. These, generally, all range eastward from the older formations, to which they succeed in the order of superposition. The line of section of the whole bears from Whitehaven on the north-west, to Newhaven on the German Ocean by south-east, where, along this course,every formation in the island is intersected, ascending from the granite of the Cumbrian mountains through all the intermediate series to the London clay and upper tertiaries. The strata of which these formations consist are all, more or less, inclined to the horizon, dipping under each other, and emerging in succession to the surface. The outcrop is at right angles to the line of section, so that each class of rocks rises to and faces the north-west, meeting the eye of the geologist as they are in turn approached, and narrowing in extent and receding in proportion as they are vertically removed from the older systems.
Hence, were our researches to begin here, instead of in the Grampian range, the starting point would necessarily be in the Lake mountains. The crystalline primary rocks are developed, though sparingly, in this district; and these, again, are surrounded and overlaid by the lowest fossiliferous deposits, termed by their explorer and historian, “The Cumbrian System.” All the driest details of the science are here too amply relieved by the charming and magnificent scenery amidst which they fall to be wrought out, where the inner and outer arrangements of Nature, in the disposition of her works, are alike fitted to call forth our admiration and delight. The author of “Elia,” who had spent his days in a city life and had a prejudice against every other mode of consuming time, upon his first excursion so far into the country, describes Coleridge as “dwelling upon a small hill by the side of Keswick, in a comfortable house, quite enveloped on all sides by a net of mountains; great floundering bears and monsters they seemed, all couchant and asleep.” It was enough; the soul of the man of genius was stirred. He clambered up to the top of Skiddaw; and he waded up the bed of the Lodore; and he satisfied himself, “that there is such a thing as tourists callromantic.” But Lamb was never meant for a geologist, and for science of any kind he had no aptitude. The athletic Wordsworth is of a different mold, compacted of different elements, a mind stored with the loveliest images; an understanding capable of sounding the depths of any subject, and a thirst after knowledge from all and every source of visible creation; and yet, mark how disparagingly he pronounces judgment upon the student ofunquestionably the most poetical of all the branches of physical inquiry—“that fellow wanderer”—
“He who with pocket hammer smites the edgeOf luckless rock or prominent stone,The substance classes by some barbarous name,And hurries on;and thinks himself enriched,Wealthier, and doubtless wiser, than before.”
“He who with pocket hammer smites the edgeOf luckless rock or prominent stone,The substance classes by some barbarous name,And hurries on;and thinks himself enriched,Wealthier, and doubtless wiser, than before.”
“He who with pocket hammer smites the edgeOf luckless rock or prominent stone,The substance classes by some barbarous name,And hurries on;and thinks himself enriched,Wealthier, and doubtless wiser, than before.”
“He who with pocket hammer smites the edge
Of luckless rock or prominent stone,
The substance classes by some barbarous name,
And hurries on;
and thinks himself enriched,
Wealthier, and doubtless wiser, than before.”
But men, it would seem, can no more command their moods of thought than their prejudices. The poetical vein, like the geological, will burst through all restraints to illustrate and vindicate the principles of truth. We have often repeated, recalling them from memory, as the index of our own frame of mind, while searching in the crypts of the primeval world, the beautiful lines—a hymn to Nature’s works, and the study of them—
“These barren rocks, our stern inheritance,These fertile fields, that recompense our pains,The shadowy vale, the sunny mountain top,Woods waving in the wind their lofty heads,Or hushed; the roaring waters, and the still.They see the offering of my lifted hands—They hear my lips present their sacrifice—They know if I be silent, morn or even.”
“These barren rocks, our stern inheritance,These fertile fields, that recompense our pains,The shadowy vale, the sunny mountain top,Woods waving in the wind their lofty heads,Or hushed; the roaring waters, and the still.They see the offering of my lifted hands—They hear my lips present their sacrifice—They know if I be silent, morn or even.”
“These barren rocks, our stern inheritance,These fertile fields, that recompense our pains,The shadowy vale, the sunny mountain top,Woods waving in the wind their lofty heads,Or hushed; the roaring waters, and the still.They see the offering of my lifted hands—They hear my lips present their sacrifice—They know if I be silent, morn or even.”
“These barren rocks, our stern inheritance,
These fertile fields, that recompense our pains,
The shadowy vale, the sunny mountain top,
Woods waving in the wind their lofty heads,
Or hushed; the roaring waters, and the still.
They see the offering of my lifted hands—
They hear my lips present their sacrifice—
They know if I be silent, morn or even.”
Nor does it rest here, for directly is our science under a deep debt of gratitude to the author of the “Excursion,” who sought for and obtained the aid of the geologist’s pencil to fill up the outline of his own sweet picture of the “Scenery of the Lakes.” Read side by side, one may well ask, whether the descriptions of the poet, or the sketches of the philosopher, are the more buoyant in diction, diversified in illustration, or pregnant with devotional inspiration. The work of Wordsworth and Sedgwick as a companion of travel is without a rival, in which, and out of the darkest pages of creation, we see the light of science falling upon, as if intending in verity to produce, an illuminated volume, and over which, at one and the same moment imagination is throwing her gayer and softer colorings. The physical structure of the district,in fact, furnishes the key to all its picturesque and delicious scenery. The geology and the poetry are the counterparts of each other. Wordsworth has drank deep at the fountains, and told the story of the one: the lessons of the other have been read by a kindred spirit, who has heard the mighty voice muttered in the dark recesses of the earth, and, in his own eloquently impassioned diction, Sedgwick has recorded the truths “of wisdom, of inspiration, and of gladness; telling us of things unseen by vulgar eyes—of the mysteries of creation—of the records of God’s will before man’s being—of a spirit breathing over matter before a living soul was placed within it—of laws as unchangeable as the oracles of nature.” And out of all the apparent confusion, and multiplicity of objects so blended together, he has brought “harmonies” to light, which are to have “their full consummation only in the end of time, when all the bonds of matter shall be cast away, and there shall begin the reign of knowledge and universal love.”
Structure of the Cumbrian Group.1. Granite.2. Skiddaw Slate.3. Green Roofing Slate, Porphyry, &c.4. Coniston Limestone.5. Silicious Grits.6. Ireleth Slates.7. Slaty Flagstone.8. Old Red Sandstone.9. Carboniferous Limestone.10. Magnesian Limestone, and New Red Sandstone.
Structure of the Cumbrian Group.1. Granite.2. Skiddaw Slate.3. Green Roofing Slate, Porphyry, &c.4. Coniston Limestone.5. Silicious Grits.6. Ireleth Slates.7. Slaty Flagstone.8. Old Red Sandstone.9. Carboniferous Limestone.10. Magnesian Limestone, and New Red Sandstone.
Structure of the Cumbrian Group.
Thus, as seen in the preceding section, four geological systems are, in this charming district of lakes and mountains, all clustered together and rolled up for the convenient inspection of a few days’ rambles: The Silurian, Devonian, Carboniferous, and Permian: and to these are to be added the Granites, Porphyries, and Plutonic family of greenstones and basalts.