CHAPTER III.
THE ANCIENT EPOCH.
“Where wast thou when I laid the foundations of the earth?”—Job xxxviii. 4.
And now in right earnest let us begin our examination of the earth’s crust. Some of the terms we may use will, perhaps, at first sight appear repulsive from their novelty and difficulty; such words we will explain as we proceed, and will only stay the student’s course to remark, that there is a necessity for the use of the dead languages in the formation of compound terms that are to become descriptive names, and in their application to newly discovered objects. This necessity arises from the fact that it is only in this way that scientific men of different nations can understand the character of each other’s researches, and compare notes with one another. A fossil is found, let us suppose, in the lias formation; it proves to be the organic remains of some very strange and anomalous creature. People go down to Lyme Regis to examine it, and, in doing so, discover others. Comparative anatomists arrange the dislocated parts and give them a name; this must be intelligible to geologists on the Continent as well as in England; and therefore some term descriptive of the animal, once the living possessor of these “dry bones,” must be given, and finally it is called ichthyosaurus. Any one in Russia, or Austria, or Italy, who happened to be acquainted with the rudiments of Greek, would know at once the kind of animal referred to by its very name, derived from ichthus, a fish, and sauros, a lizard. This would indicate to all scientific men the nature of this remarkable animal, of which we shall have to tell some stories by and by as full of wonder as any modern or ancient book of marvels; while, if we had called it fish-lizard, only those who understood English would know what we meant. Our object is to simplify as much as possible every difficult term that may be used; but while we solicit our readers to master each difficulty as it rises, we hope they will not think that, when they have read this little book, they are masters of Geology, our highest ambition being only to impart a taste for the science.
To return: our examination commences with the Plutonic rocks, so called in memory of the well-known mythological god of the fiery or infernal regions; and we take granite[[14]] as a type of these rocks, because it is so familiar to all our readers. There are besides granite, syenite,[[15]] greenstone, porphyry, basalt, and others, to dilate upon which would defeat our purpose. Our object is to lay but a little at a time upon the memory, and to let that little be well digested before we pass from the thoroughly known to the unknown. Nothing but actual examination can make the student familiar with the varieties of the rocks of this very ancient epoch in the world’s history. Well, everybody knows what granite is; they see it on the kerb-stones of the wayside, in the hard paving of the London streets, in the massive slabs of London and Waterloo Bridges, and elsewhere. “Granite!” exclaims the reader, “everybody knows what granite is, and there is an end of it; you make as much fuss about granite as Wordsworth did about his well-known primrose, and the man who could see nothing but a primrose in a primrose.”
But there is a poetry and a history about granite upon which we are going to dwell. This piece of granite which I hold in my hand is composed of quartz, mica, and feldspar.[[16]] The quartz is white and hard—I can’t scratch it with my knife; the mica is in glistening plates or scales; and the feldspar is soft and greyish, and can easily be scratched. Oh, if this granite could speak, what a story could it tell! “To give it, then, a tongue were wise in man.” Let us try. “Once upon a time, long, long ages ago, incalculable periods before Adam was placed in possession of Eden, I, the granite, and my contemporaries, came into being. Before us, this planet ‘was without form and void.’ A dark chaotic period, of which I know nothing, preceded me. When I first emerged into being, at the command of Him who laid the foundations of the earth, this world was a barren, lifeless, uncultivated, uninhabited, untrodden, seasonless waste. Here and there were undulations of land and water, but all was bare, desolate, and silent: not a moss nor a lichen covered the ancient skeleton of the globe; not a sea-weed floated in the broad ocean; not a trace existed even of the least highly organized animal or vegetable; everything was still, and with the stillness of universal death. The earth was prepared, and the fiat of creation had gone forth; but there was no inhabitant, and no beings endowed with life had been introduced to perform their part in the great mystery of creation.”[[17]] And the granite might go on to say—“Man! of three-score years and ten, where wast thou when He, my Maker and yours, laid the foundations of the earth? Let me tell you what an important part I have played in the history of your world’s formation. I rise to the highest elevations, and form the sublimest pinnacles on the surface of the globe, and without me your scenery would lose its grandeur and its glory. But for me Albert Smith had never climbed Mont Blanc, nor Humboldt Cotopaxi and Chimborazo; nor would the head of the famed Egyptian Memnon[[18]] have been sculptured. You may see me giving to Cornwall, Wales, and Scotland their most valuable minerals and metals. In Europe
‘I am monarch of all I survey,
My right there is none to dispute.’
The Scandinavians, the Hartz mountains, the Alps, and the Pyrenees are mine; nor is my territory less in Asia, Africa, the great Americas, and in the becoming great Australia; and thus, by my deeply rooted foundations and my vast extension, I constitute the framework, solid and immoveable, of this ‘great globe and all that it inherits.’”
Thus, at any rate, the granite might speak, nor would there be one word of vain boasting in it. Having beard it, or fancied we heard it, which amounts to the same thing, let us soberize ourselves, and put granite into the third person. There are no fossils in granite and the other Plutonic and volcanic rocks; even supposing any forms of life to have been in existence at the period to which we are referring, the action of fire has annihilated all their remains. We should not therefore expect in Cumberland and Cornwall, nor in those parts of Devonshire where granite prevails, to find the fossils peculiar to other formations with which in time we hope to make familiar acquaintance. But though destitute of interest in this respect, how great is its importance and interest in those economic uses which have the geologist for their guide, and the whole family of man for their beneficent operations! “Many varieties of granite are excellent as building stones, though expensive in working to definite forms. Some of the most important public works of Great Britain and Ireland, France and Russia, are of this material. In selecting granite, those varieties in which the constituent minerals and the scales of mica are superabundant, should be avoided; and, as a practical test, it is wise to notice the country immediately around the quarry, as the sandy varieties rapidly disintegrate,[[19]] and form accumulations of micaceous sand. The Hayter or Dartmoor granite, the Aberdeen granite, the Kingstown (Dublin) granite, some beds of the Mourne or county of Down granite, and the Guernsey or Channel Island granite, are well known for their excellence. In some of the quarries the bedding of the granite is more defined than in others; and wherever this is the case, or where marked cleavages or joints prevail, the work is much facilitated. Many old Egyptian works and statues were formed of granite, and it is still used for colossal works, as it takes a fine polish. For example, the great fountain shell, or vase, before the Museum at Berlin, and the pedestal of Peter the Great at St. Petersburg, are of the northern granite, being sculptured from erratic blocks. The splendid Scotch granite columns, in the vestibule of the Fitzwilliam Museum at Cambridge, are beautiful examples of a modern application of this rock to the arts.”[[20]]
It is also in the Plutonic or igneous rocks that almost all the metals are found; and here we have our first illustration of that order to which we shall frequently call attention; an order as exquisite as can be found in the drawers of a lady’s cabinet, forbidding the thought that anything observable at the present time, in the bowels or on the surface of the crust of the earth, can be attributed to the violent diluvial action of the Noachian deluge. The diagram below represents an ideal section of a mining district.