philosophers, must vanish, in a more extensive view of the operations of the globe; but it is certain that granite, or a species of the same kind of stone, is thus found stratified. It is the _granit feuilletee_ of M. de Saussure, and, if I mistake not, what is called _gneis_ by the Germans. We have it also in our north alpine country of Scotland; of this I have specimens, but have not seen it in its place.
Granite being thus found stratified, the masses of this stone cannot be allowed to have any right of priority over the schistus, its companion in the alpine countries, although M. de Saussure, whose authority I would revere, has given it for the following reason; that it is found the most centrical in the chains of high mountains, or in alpine countries. Now, supposing this fact to be general, as he has found it in the Alps, no argument for the priority of those masses can be founded either upon the height or the situation of those granite mountains; for the height of the mountain depends upon the solidity and strength of the stone. Now though it is not to be here maintained that granite is the most durable of those alpine rocks, yet as a mountain, either granite in general, or in particular, certain species of it, may be esteemed such, consequently, this massy stone, remaining highest in the mountainous region, will naturally be considered as the centre, and according to this rule, as having the pre-eminence in point of seniority.
The rock which stands in competition with granite for the title of primitive in the order of mountains, is that micaceous stratified stone which is formed chiefly of quartz, but which admits of great variety like the granite. The difference between those two bodies does not consist in the materials of which they are composed, for, in their varieties, they may be in this respect the same, but in a certain regularity of composition, in this alpine stone, which evidently arises from stratification or subsidence in water.
If we shall thus consider all the varieties of this alpine stone as being of one kind, and call it granite, then we shall distinguish in this body two different species, from whence perhaps some interesting conclusion may be formed with regard to the operations of the globe. These two species are, _first_, granite regular in its composition, or stratified in its construction; and, _secondly_, granite in mass, or irregular in its construction. Let us now endeavour to make use of these generalizations and distinctions.
In examining the great diversity of our whinstone, trap, or basaltes, it is found at last to granulate into granite; at the same time those two different species of rock-stone may be distinguished. A perfect granite has not in its composition necessarily any argillaceous earth, farther than may be in the natural constitution of its distinct parts; whereas, a perfect basalt may have abundance of this substance, without any quartz or any siliceous body. A perfect granite, is, therefore, an extremely hard stone, having quartz and feldspar for its basis; but a perfect whin or basaltes may be extremely soft, so as to cut easily with a knife. In like manner granite is a composition which graduates into porphyry; but porphyry is only whinstone of a harder species. Therefore, though perfectly distinct, those three things graduate into each other, and may be considered as the same.
Granite and whinstone, or basaltes, though distinct compositions, thus graduating into each other; and whinstone, as well as porphyry, being without doubt a species of lava, we may consider the granite which is found in mass without stratification, in like manner as we do the masses of whinstone, basaltes, or Swedish trap, as having flowed in the bowels of the earth, and thus been produced by the chance of place, without any proper form of its own, or in an irregular shape and construction. In this manner would be explained the irregular shape or structure of those granite masses; and thus great light would be thrown upon the waved structure of the stratified alpine stone, which, though it has not been made to flow, has been brought to a great degree of softness, so as to have the original straight lines of its stratification changed to those undulated or waving lines which are in some cases extremely much incurvated.
It remains only to confirm this reasoning, upon our principles, by bringing actual observation to its support; and this we shall do from two of the best authorities. The Chevalier de Dolomieu, in describing the volcanic productions of Etna, mentions a lava which had flowed from that mountain, and which may be considered as a granite. But M. de Saussure has put this matter out of doubt by describing most accurately what he had seen both in the Alps and at the city of Lyons. These are veins of granite which have flowed from the contiguous mass into the stratified stone, and leave no doubt with regard to this proposition, that the granite had flowed in form of subterranean lava, although M. de Saussure has drawn a very different conclusion from this appearance. I have also a specimen from this country of a vein of granite in a granite stone, the vein being of a smaller grain than that of the rock which it traverses.[20]
[Note 20: This is what I had wrote upon, the subject of granite, before I had acquired such ample testimony from my own observations upon that species of rock. I have given some notice, in the 3d vol. of the Transactions of the Edinburgh R.S. concerning the general result of those observations, which will be given particularly in the course of this work.]
It will thus appear, that the doctrine which of late has prevailed, of primitive mountains, or something which should be considered as original in the construction of this earth, must be given up as a false view of nature, which has formed the granite upon the same principle with that of any other consolidated stratum; so far as the collection of different materials, and the subsequent fusion of the compound mass, are necessary operations in the preparation of all the solid masses of the earth. Whatever operations of the globe, therefore, may be concluded from the composition of granite masses, as well as of the alpine strata, these must be considered as giving us information with regard to the natural history of this earth; and they will be considered as important, in proportion as they disclose to us truths, which from other strata might not be so evident, or at all made known.
Let us now examine the arguments, which, may be employed in favour of that supposition of primitive mountains.
The observations, on which naturalists have founded that opinion of originality in some of the component parts of our earth, are these; _first_, They observe certain great masses of granite in which stratification is not to be perceived; this then they say is an original mass, and it is not to be derived from any natural operation of the globe; _secondly_, They observe considerable tracts of the earth composed of matter in the order of stratification as to its general composition, but not as to its particular position, the vertical position here prevailing, instead of the horizontal which is proper to strata formed in water; this, therefore, they also term primitive, and suppose it to be from another origin than that of the subsidence of materials moved in the waters of the globe; _lastly_, They observe both strata and masses of calcareous matter in which they cannot distinguish any marine body as is usual in other strata of the same substance; and these calcareous masses being generally connected with their primitive mountains, they have also included these collections of calcareous matter, in which marine bodies are not observed, among the primitive parts which they suppose to be the original construction of this globe.
It may be proper to see the description of a calcareous alpine mountain. M. de Saussure gives us the following observations concerning a mountain of this kind in the middle of the Alps, where the water divides in running different ways towards the sea. It is in describing the passage of the Bon-Homme, (Tom. 2. V. dans les Alpes).
“Sec. 759. Sur la droite ou au couchant de ces rochers, on voit une montagne calcaire etonnante dans ce genre par la hardiesse avec laquelle elle eleve contre le ciel ses cimes aigues et tranchantes, taillees a angles vifs dans le costume des hautes cimes de granit. Elle est pourtant bien surement calcaire, je l’ai observee de pres, et on rencontre sur cette route les blocs qui s’en detachent.
“Cette pierre porte les caracteres des calcaires les plus anciennes; sa couleur est grise, son grain assez fin, on n’y appercoit aucun vestige de corps organises; ses couches sont peu epaisses, ondees et coupees frequemment par des fentes paralleles entr’elles et perpendiculaires a leurs plans. On trouve aussi parmi ces fragmens des breches calcaires grises.”
Here is a mountain which will rank with the most primitive of the earth; But why? only because it is extremely consolidated without any mark of organised body. Had there been in this mountain but one single shell, we should not then have scrupled to conclude that the origin of this lofty mountain had been the same with every marble or limestone in the earth. But though, from the structure of this stone, there is no mark of its having been formed immediately of the calcareous parts of animals, there is every mark of those calcareous strata having been formed like other marbles by deposit in the waters of the globe.
These two things are also homologated by the equal or perfect consolidation of their substance; for, as it is to be proved that all stratified marbles have been consolidated by the fusion of their substance, we must attribute the same consolidating cause to those alpine masses; the frequent veins that divide those calcareous strata which M. de Saussure has here described, also prove the nature of the consolidating cause, (see Chap. 1. page 111.).
This mountain, considered by itself, may perhaps afford no data by which a naturalist might read the circumstances of its origin. But, Is a theory of the earth to be formed upon such a negative observation? and, Is there any particular in this mountain, that may not be shown in others of which the origin is not in any degree doubtful?
It is not to be disputed, that there are parts of the solid body of our earth which may be considered as primary or prior, compared with others that are posterior, in relation to the time of their formation, and much less changed with regard to the state in which they had been originally formed:–But it is here denied, that there are any parts of the earth which do not appear to have had the same origin with all the rest, so far as this consists in the collection of materials deposited at the bottom of the waters[21]; for there is no solid mass of land that may not be traced to this origin, either from its composition, or from its local connection with other masses, the nature of which in this respect are known. We have already given examples of this from sufficient authority. The evidence, therefore, of those primary masses being original in relation to the natural operations of the globe, is reduced to this assertion, that there are no vestiges of organised bodies to be found in those primary masses. Let us now examine how far this testimony for the originality of those masses is to be admitted in fact and sound reasoning.
[Note 21: There are no collection of those alpine masses in which may not be found in some of them sand, mica, and gravel; but these materials prove the existence of an earth, on which those fragments of greater masses had been formed, and more or less worn by attrition.]
The matter in question at present is this, that there are certain tracts of countries in which no vestige of organised bodies are found; now, let us suppose the fact to be true or well grounded, Can we conclude from this that there had been originally no organised bodies in the composition of those masses?–Such a conclusion could only be formed in making a supposition, that every organised body deposited in a mass of matter, whether homogeneous or heterogeneous, should be preserved without change, while the collected mass, in which it had been deposited, changes as much as possible by the operation both of fire and water. But this supposition is erroneous, and cannot be admitted; and the study of marbles will demonstrate this truth, that the calcareous relics of organised bodies are changed, in the consolidating operations of the globe, in every degree, from the smallest alteration to the greatest, when they become indistinguishable any farther to our sight.
Therefore, from the supposition of no appearance of marine bodies in the pretended primitive masses, there is no sufficient evidence or reason to conclude, that those masses have not had a marine origin; because, the traces of organised bodies may be obliterated by the many subsequent operations of the mineral region; and which operations, the present state of those masses certify beyond dispute.
We are now to examine the fact, how far the ground on which that false reasoning had been founded is strictly true.
In the first place, then, it must be considered, that the alledged fact is nothing but a negative assertion, importing that no mark of organised bodies had been observed, in certain stones and strata which some naturalists have examined with that view. But, though many naturalists have looked for them without success, it does not follow that such marks may not be found; it indeed proves that such a task is difficult, and the success of it, to a particular, most precarious; accident, however, may bring about what the greatest industry has not been able to attain. Secondly, there is good reason to believe that this asserted negation is not absolutely true; for I have in my possession what I consider as proof of the contrary; I found it in Wales, and I think it is in what may be considered as primitive mountains;–it is the mark of shells in a stone of that kind.
Thus, I had formed my opinion with regard to this alleged fact, long before I had seen any description either of the Alps or Pyrennean mountains; and now I have no reason to change that opinion. It may indeed be alleged, that the strata of marble or limestone, containing marine bodies found in those mountains, are secondary strata, and not the primitive. To this I can give no reply, as the descriptions given of those strata do not enable me to decide this point.
At the village of Mat, under the Mont Blatten for example, there is a quarry of schistus or black slate, in which are often found the print and the bones of fishes. (Discours sur l’Histoire Naturelle de la Suisse, page 225.). If this may be considered as an alpine or primitive schistus, it would be decisive of the question: But it would require to have it well ascertained that this schistus is truly one of those which are esteemed primitive, or that it is properly connected with them.
But though I cannot find in those interesting descriptions which we now have got, any one which is demonstrative of this truth, that calcareous marine objects are found in the primitive strata, this is not the case with regard to another object equally important in deciding this question, Whether the primitive strata are found containing the marks of organised bodies?
M. de Dellancourt, in his _Observations Mineralogiques_, Journal de Physique Juillet 1786, in describing the mountains of Dauphine, gives us the following fact with regard to those alpine vertical strata.
“La pierre constituante de la montagne d’Oris est en general le _Kneifs_ ou la roche feuilletee mica et quartz a couches plus ou moins ferrees quelquefois le schorl en roche penetre de steatite. Les couches varient infiniment quant a leur direction et a leur inclinaisons. Cette montagne est cultivee et riche dans certain cantons, surtout autour du village d’Oris, mais elle est tres-escarpee dans beaucoup d’autres. Entre le village d’Oris et celui du Tresnay est une espece de combe assez creuse formee par la chute des eaux des cimes superieures des rochers. Cette combe offre beaucoup de schiste dont les couches font ou tres-inclinees ou perpendiculaires. Entre ces couches il s’en est trouve de plus noires que les autres et capable de bruler, mais difficilement. Les habitans ont extrait beaucoup de cette matiere terreuse, et lui ont donne le nom de charbon de terre. Ils viennent meme a bout de la faire bruler, et de s’en servir l’hiver en la melant avec du bois. Ce schiste noir particulier m’a paru exister principalement dans les endroits ou les eaux se sont infiltrees entre les couches perpendiculaires, et y ont entraine diverse matieres, et sur-tout des debris de vegetaux que j’ai encore retrouves a demi-noirs, pulverulens et comme dans un etat charbonneux.”
This formation of coal, by the infiltration of water and carrying in of vegetable bodies, certainly cannot be admitted of; consequently, from this description, there would seem to be strata of coal alternated with the alpine schisti. But the formation of mineral coal requires vegetable matter to have been deposited along with those earthy substances, at the bottom of the sea. The production of vegetable bodies, again, requires the constitution of sea and land, and the system of a living world, sustaining plants at least, if not animals.
In this natural history of the alpine schisti, therefore, we have a most interesting fact, an example which is extremely rare. Seldom are calcareous organised bodies found among those alpine strata, but still more rarely, I believe, are the marks of vegetable bodies having contributed in the formation of those masses. But however rare this example, it is equally decisive of the question, Whether the alpine schisti have had a similar origin as the other strata of the globe, in which are found abundance of animal and vegetable bodies, or their relics? and we are authorised to say, that since those perfect alpine strata of Dauphine have had that origin, all the alpine schisti of the globe have been originally formed in a similar manner. But to put this matter out of doubt:
In this summer 1788, coming from the Isle of Man, Mr Clerk and I traveled through the alpine schistus country of Cumberland and Westmoreland. We found a limestone quarry upon the banks of Windermere, near the Low-wood Inn. I examined this limestone closely, but despaired of finding any vestige of organised body. The strata of limestone seem to graduate into the slate or schistus strata, between which the calcareous are placed. Fortunately, however, I at last found a fragment in which I thought to perceive the works of organised bodies in a sparry state; I told Mr Clerk so, and our landlord Mr Wright, who had accompanied us. I have brought home this specimen, which I have now ground and polished; and now it is most evidently full of fragments of entrochi. Mr Wright then told me he had seen evident impressions of marine objects, as I understood from the description, in the slate of those mountains; and he was to send me specimens so soon as he could procure them.
Here is one specimen which at once overturns all the speculations formed upon that negative proposition. The schistus mountains of Cumberland were, in this respect, as perfect primitive mountains as any upon the earth, before this observation; now they have no claim upon that score, no more than any limestone formed of shells.
When I first announced my belief that such objects in natural history might be found, I little thought to have seen it realised, to such a degree as has now happened in the little circle of my knowledge. In the summer 1791,
Professor Playfair was to pass through Cumberland. I begged that he would inquire of Mr Wright, at the Low-wood Inn, for those objects which he was to endeavour to procure for me, and to examine the limestone quarry in which I had found the specimen with entrochi. He went through another part of those primary mountains, and has found examples of this kind in the schisti; concerning which he has written me the following account.
“In a visit which I made to the Lakes of Cumberland in September 1791, in company with the Hon. Francis Charteris, I met with a limestone full of marine objects, though from its position it is certainly to be reckoned among the primary strata. The place where we found this stone was in the district of Lancashire, that is west of Windermere Lake, on the road from Ambleside to the north end of Coniston Lake, and not far from the point when you come in sight of the latter. Just about this spot we happened to meet with one of those people who serve as guides to travelers in those parts, and who told us, among other things, that stones with shells in them were often found not far from where we were then walking. We immediately began to look about for specimens of that kind, and soon met with several; the most remarkable of which was in a rock that rose a little above the surface, about 300 or 400 yards to the right of the road. It was a part of a limestone stratum, nearly vertical, and was full of bivalves with the impressions as strong as in a common secondary limestone. The strata on both sides had the same inclination, and were decidedly primary, consisting of the ordinary micaceous schistus. This however I need not remark to you, who know so well from your own observations that the whole of the country I am now speaking of has every character of a primary one. I, only mention it, that it may not be supposed that the rock in question was some fragment of a secondary stratum that remained, after the rest was washed away, superincumbent on the primary.
“After I had seen this rock, I recollected that you had told me of something of the same kind that you saw in a quarry at Low-wood Inn; and it may be that both belonged to the same stratum or body of strata; for the direction of the strata, as nearly as I could observe, was from S.W. to N.E.; and this also is nearly the bearing of Low-wood from the place where we now were. I send you a specimen, which you can compare with those you brought from the lime quarry at Low-wood.”
I have examined this specimen, and find it to be the common schistus of that country, only containing many bivalve shells and fragments of entrochi and madrapore bodies, and mixed with pyrites.
I have already observed that one single example of a shell, or of its print, in a schistus, or in a stone stratified among those vertical or erected masses, suffices to prove the origin of those bodies to have been, what I had maintained them to be, water formed strata erected from the bottom of the sea, like every other consolidated stratum of the earth. But now, I think, I may affirm, that there is not, or rarely, any considerable extent of country of that primary kind, in which some mark of this origin will not be found, upon careful examination; and now I will give my reason for this assertion. I have been examining the south alpine country of Scotland, occasionally, for more than forty years back, and I never could find any mark of an organised body in the schistus of those mountains. It is true that I know of only one place where limestone is found among the strata; this is upon Tweed-side near the Crook. This quarry I had carefully examined long ago, but could find no mark of any organised body in it. I suppose they now are working some other of the vertical strata near those which I had examined; for, in the summer 1792, I received a letter from Sir James Hall, which I shall now transcribe. It is dated at Moffat, June 2. 1792.
“As I was riding yesterday between Noble-house and Crook, on the road to this place, I fell in with a quarry of alpine limestone; it consists of four or five strata, about three feet thick, one of them single, and the rest contiguous; they all stand between the strata of slate and schist that are at the place nearly vertical. In the neighbourhood, a slate quarry is worked of a pure blue slate; several of the strata of slate near the limestone are filled with fragments of limestone scattered about like the fragments of schist in the sandstone in the neighbourhood of the junction on our coast.[22]
[Note 22: This has a reference to very curious observations which we made upon the east coast where these mountains terminate, and which I am to describe in the course of this work.]
“Among the masses of limestone lately broken off for use, and having the fractures fresh, I found the forms of cockles quite distinct; and in great abundance.–I send you three pieces of this kind,” etc.
It may perhaps be alleged that those mountains of Cumberland and Tweedale are not the primary mountains, but composed of the secondary schistus, which is every where known to contain those objects belonging to a former earth. Naturalists who have not the opportunity of convincing themselves by their proper examination, must judge with regard to that geological fact by the description of others. Now it is most fortunate for natural history, that it has been in this range of mountains that we have discovered those marks of a marine origin; for, I shall afterwards have occasion to give the clearest light into this subject, from observations made in other parts of those same mountains of schist, by which it will be proved that they are the primary strata; and thus no manner of doubt will then remain in the minds of naturalists, who might otherwise suspect that we were deceiving ourselves, by mistaking the secondary for the primitive schistus.
I have only farther to observe, that those schisti mountains of Wales, of Cumberland, and of the south alpine part of Scotland, where these marine objects have been found, consist, of that species of stone which in some places makes the most admirable slate for covering houses; and, in other parts, it breaks into blocks that so much resemble wood in appearance, that, without narrow inspection, it might pass for petrified wood.
We are therefore to conclude that the marks of organised bodies in those primary mountains are certainly found; at the same time the general observation of naturalists has some foundation, so far as the marks of organised bodies are both rarely to be met with in those masses, and not easily distinguished as such when they are found.
But this scarcity of marine objects is not confined to those primary mountains, as they are called; for among the most horizontal strata, or those of the latest production, there are many in which, it is commonly thought, no marine calcareous objects are to be found; and this is a subject that deserves to be more particularly considered, as the theory may thus receive some illustration.
Sandstone, coal, and their accompanying strata, are thought to be destitute of calcareous marine productions, although many vestiges of plants or vegetable productions are there perceived. But this general opinion is neither accurate nor true; for though it be true that in the coal and sandstone strata it is most common to find marks of vegetable production, and rarely those calcareous bodies which are so frequent in the limestone, yet it is not unusual for coal to be accompanied with limestone formed of shells and corals, and also with ironstone containing many of those marine objects as well as wood. Besides, sandstone frequently contains objects which have been organised bodies, but which do not belong to the vegetable kingdom, at least to no plant which grows upon the land, but would seem to have been some species of zoophite perhaps unknown.
I have also frequently seen the vestige of shells in sandstone, although in these strata the calcareous bodies are in general not perceived. The reason of this is evident. When there is a small proportion of the calcareous matter in the mass of sand which is pervious to steam and to the percolation of water, the calcareous bodies may be easily dissolved, and either carried away or dispersed in the mass; or even without being thus dispersed by means of solution, the calcareous matter may be absorbed by the siliceous substance of the stratum by means of fusion, or by heat and cementation. The fact is, that I have seen in sandstone the empty mould of marine shells with some siliceous crystallization, so far as I remember, which corresponded perfectly with that idea. The place I saw this was in a fine white sandstone accompanying the coal, upon the sea side at Brora in Sutherland.
Mineralogy is much indebted to Mr Pallas for the valuable observations which he has given of countries so distant from the habitations of learned men. The physiology of the globe has also been enriched with some interesting observations from the labours of this learned traveller. But besides giving us facts, Mr Pallas has also reasoned upon the subject, and thus entered deep into the science of Cosmogeny; here it is that I am afraid he has introduced some confusion into the natural history of the earth, in not properly distinguishing the mineral operations of the globe, and those again which belong entirely to the surface of the earth; perhaps also in confounding the natural effects of water upon the surface of the earth, with those convulsions of the sea which may be properly considered as the accidental operations of the globe. This subject being strictly connected with the opinions of that philosopher with regard to primitive mountains, I am obliged to examine in this place matters which otherwise might have come more properly to be considered in another.
M. Pallas in his _Observations sur la formation des montagnes_, (page 48) makes the following observations.
“J’ai deja dit que _la bande de montagnes primitives schisteuses_ heterogenes, qui, par toute la terre, accompagne les chaines granitiques, et comprend les roches quartzeuses et talceuses mixtes, trapezoides, serpentines, le schiste corne, les roches spathiques et cornees, les grais purs, le porphyre et le jaspre, tous rocs feles en couches, ou presque perpendiculaires, ou du moins tres-rapidement inclinees, (les plus favorables a la filtration des eaux), semble aussi-bien que le granit, anterieure a la creation organisee. Une raison tres-forte pour appuyer cette supposition, c’est que la plupart de ces roches, quoique lamelleuse en facon d’ardoise, n’a jamais produit aux curieux la moindre trace de petrifactions ou empreintes de corps organises. S’il s’en est trouve, c’est apparemment dans des fentes de ces roches ou ces corps ont ete apportes par un deluge, et encastrees apres dans une matiere infiltree, de meme qu’on a trouve des restes d’Elephans dans le filon de la mine d’argent du Schlangenberg.[23] Les caracteres par lesquels plusieurs de ces roches semblent avoir souffert des effets d’un feu-tres-violent, les puissantes veines et amas des mineraux les plus riches qui se trouvent principalement dans la bande qui en est composee, leur position immediate sur le granit, et meme le passage, par lequel on voit souvent en grand, changer le granit en une des autres especes; tout cela indique une origine bien plus ancienne, et des causes bien differentes de celles qui ont produit les montagnes secondaires.”
[Note 23: This is a very natural way of reasoning when a philosopher finds a fact, related by some naturalists, that does not correspond with his theory or systematic view of things. Here our author follows the general opinion in concluding that no organised body should be found in their primitive strata; when, therefore, such an object is said to have been observed, it is supposed that there may have been some mistake with regard to the case, and that all the circumstances may not have been considered. This caution with regard to the inaccurate representation of facts, in natural history, is certainly extremely necessary; the relicts of an elephant found in a mineral vein, is certainly a fact of that kind, which should not be given as an example in geology without the most accurate scientifical examination of the subject.]
Here M. Pallas gives his reason for supposing those mountains primitive or anterior to the operations of this globe as a living world; _first_, because they have not, in general, marks of animals or plants; and that it is doubtful if they ever properly contain those marks of organised bodies; _secondly_, because many of those rocks have the appearance of having suffered the effects of the most violent fire. Now, What are those effects? Is it in their having been brought into a fluid state of fusion. In that case, no doubt, they may have been much changed from the original state of their formation; but this is a very good reason why, in this changed state, the marks of organised bodies, which may have been in their original constitution, should be now effaced.
The _third_ reason for supposing those mountains primitive, is taken from the metallic veins, which are found so plentifully in these masses. Now, had these masses been the only bodies in this earth in which those mineral veins were found, there might be some species of reason for drawing the conclusion, which is here formed by our philosopher. But nothing is so common (at least in England) as mineral veins in the strata of the latest formation, and in those which are principally formed of marine productions; consequently so far from serving the purpose for which this argument was employed, the mineral veins in the primitive mountains tend to destroy their originality, by assimilating them in some respect with every other mass of strata or mountain upon the globe.
_Lastly_, M. Pallas here employs an argument taken from an appearance for which we are particularly indebted to him, and by which the arguments which have been already employed in denying the originality of granite is abundantly confirmed. It has been already alleged, that granite, porphyry, and whinstone, or trap, graduate into each other; but here M. Pallas informs us that he has found the granite not only changed into porphyry, but also into the other alpine compositions. How an argument for the originality of these mountains can be established upon those facts, I am not a little at a loss to conceive.
The general mineralogical view of the Russian dominions, which we have, in this treatise, may now be considered with regard to that distinction made by naturalists, of primitive, secondary, and tertiary mountains, in order to see how far the observations of this well informed naturalist shall be found to confirm the theory of the earth which has been already given, or not.
The Oural mountains form a very long chain, which makes the natural division betwixt Europe and Asia, to the north of the Caspian. If in this ridge, as a centre of elevation, and of mineral operations, we shall find the greatest manifestation of the violent exertion of subterraneous fire, or of consolidating and elevating operations; and if we shall perceive a regular appearance of diminution in the violence or magnitude of those operations, as the places gradually recede from this centre of active force; we may find some explanation of those appearances, without having recourse to conjectures which carry no scientific meaning, and which are more calculated to confound our acquired knowledge, than to form any valuable distinction of things. Let us consult M. Pallas how far this is the case, or not.
After having told us that all those various alpine schisti, jaspers, porphyries, serpentines, etc. in those mountains, are found mutually convertible with granite, or graduating into each other, our author thus continues, (p. 50).
“On entrevoit de certaines loix a l’egard de l’arrangement respectif de cet ordre secondaire d’anciennes roches, par tous les systemes de montagnes qui appartiennent a l’Empire Russe. La chaine Ouralique, par exemple, a du cote de l’Orient sur tout sa longueur, une tres-grande abondance de schistes cornes, serpentins et talceux, riches en filons de cuivre, qui forment le principal accompagnement du granite, et en jaspres de diverses couleurs plus exterieurs et souvent comme entrelaces avec les premiers, mais formant des suites de montagnes entieres, et occupant de tres-grands espaces. De ce meme cote, il y parait beaucoup de quartz en grandes roches toutes pures, tant dans la principale chaine que dans le noyau des montagnes de jaspre, et jusques dans la plaine. Les marbres spateux et veines, percent en beaucoup d’endroits. La plupart de ces especes ne paraissent point du tout a la lisiere occidentale de la chaine, qui n’est presque que de roche melangee de schistes argileux, alumineux, phlogistique, etc. Les filons des mines d’or melees, les riches mines de cuivre en veines et chambrees, les mines de fer et d’aimant par amas et montagnes entieres, sont l’apanage de la bande schisteuse orientale; tandis que l’occidentale n’a pour elle que des mines de fer de depots, et se montre generalement tres-pauvre en metaux. Le granit de la chaine qui borde la Siberie, est recouvert du cote que nous connaissons de roches cornees de la nature des pierres a fusil, quelquefois tendant a la nature d’un grais fin et de schistes tres-metallieres de differente composition. Le jaspre n’y est qu’en filons, ou plans obliques, ce qui est tres-rare pour la chaine Ouralique, et s’observe dans la plus grande partie de la Siberie, a l’exception de cette partie de sa chaine qui passe pres de la mer d’Okhotsk, ou le jaspre forme derechef des suites de montagnes, ainsi que nous venons de le dire des monts Ourals; mais comme cette roche tient ici le cote meridionale de la chaine Siberienne, et que nous ne lui connaissons point ce cote sur le reste de sa longueur, il se pourrait que le jaspre y fut aussi abondant. Il faudrait, au reste, bien plus de fouilles et d observations pour etablir quelque chose de certain sur l’ordre respectif qu’observent ces roches.”
I would now ask, if in all this account of the gradation of rock from the Oural mountains to the sandy coast of the Baltic, there is to be observed any clear and distinctive mark of primitive, secondary, and tertiary, mountains, farther than as one stratum may be considered as either prior or posterior to another stratum, according to the order of superposition in which they are found. We have every where evident marks of the formation of strata by materials deposited originally in water; for the most part, there is sufficient proof that this water in which those materials had been deposited was the sea; we are likewise assured that the operations of this living world producing animals, must have, for a course of time, altogether inconceivably been exerted, in preparing materials for this mass; and, lastly, from the changed constitution of those masses, we may infer certain mineral operations that melt the substance and alter the position of those horizontal bodies. Such is the information which we may collect from this mineral description of the Russian Dominions.
If we compare some of the Oural mountains with the general strata of the Russian plains, then, as to the contained minerals, we may find a certain diversity in those two places; at the same time, no greater perhaps than may be found betwixt two different bodies in those same plains, for example, chalk and flint. But when we consider those bodies of the earth, or solid strata of the globe, in relation to their proper structure and formation, we surely can find in this description nothing on which may be founded any solid opinion with regard to a different original, however important conclusions may perhaps be formed with regard to the operations of the globe, from the peculiar appearances found in alpine.
From this detail of what is found in the Oural mountains, and in the gradation of country from those mountains to the plains of Russia, we have several facts that are worthy of observation. First extensive mountains of jasper. I have a specimen of this stone; it is striped red and green like some of our marly strata. It has evidently been formed of such argillaceous and siliceous materials, not only indurated, so as to lose its character, as an argillaceous stone, but to have been brought into that degree of fusion which produces perfect solidity. Of the same kind are those hornstein rocks of the nature of flint, sometimes tending to the nature of a fine sandstone. Here is the same induration of sandstone by means of fusion, that in the argillaceous strata has produced jasper. But oblique veins of jasper are represented as traversing these last strata; now this is a fact which is not conceivable in any other way, than by the injection or transfusion of the fluid jasper among those masses of indurated strata.
All this belongs to the east side of the mountains. On the west, again, we find the same species of strata; only these are not changed to such a degree as to lose their original character or construction, and thus to be termed differently in mineralogy.
Our author then proceeds. (p. 53.)
“Nous pourrons parler plus decisivement sur les _montagnes secondaires et tertiaires_ de l’Empire, et c’est de celles-la, de la nature, de l’arrangement et du contenu de leurs couches, des grandes inegalites et de la forme du continent d’Europe et d’Asie, que l’on peut tirer avec plus de confiance quelques lumieres sur les changemens arrives aux terres habitables. Ces deux ordres de montagnes presentent la chronique de notre globe la plus ancienne, la moins sujette aux falsifications, et en meme-tems plus lisible que le caractere des chaines primitives; ce font les archives de la nature, anterieures aux lettres et aux traditions les plus reculees, qu’il etoit reserve a notre siecle observateur de feuiller, de commenter, et de mettre au jour, mais que plusieurs siecles apres le notre n’epuiseront pas.
“Dans toute l’etendue de vastes dominations Russes, aussi bien que dans l’Europe entiere, les observateurs attentifs ont remarque que generalement la band schisteuse des grandes chaines se trouve immediatement recouverte ou cottee par la _bande calcaire_. Celle-ci forme deux ordres de montagnes, tres-differentes par la hauteur, la situation de leurs couches, et la composition de la pierre calcaire qui les compose; difference qui est tres-evidente dans cette bande calcaire qui forme la lisiere occidentale de toute la chaine Ouralique, et dont le plan s’etend par tout le plat pays de la Russie. L’on observerait la meme chose a l’orient de la chaine, et dans toute l’etendue de la Siberie, si les couches calcaires horizontales n’y etaient recouvertes par les depots posterieures, de facon qu’il ne parait a la surface que les parties les plus faillantes de la bande, et si ce pays n’etoit trop nouvellement cultive et trop peu exploite par des fouilles et autres operations, que des hommes industrieux ont pratique dans les pays anciennement habites. Ce que je vais exposer sur les deux ordres de montagnes calcaires, se rapportera donc principalement a celles qui sont a l’occident de la chaine Ouralique.
“Ce cote de la dite chaine consiste sur cinquante a cent verstes de largeur, de roche calcaire solide, d’un grain uni, qui tantot ne contient aucune trace de productions marines, tantot n’en conserve que des empreintes aussi legeres qu’eparses. Cette roche s’eleve en montagnes d’une hauteur tres-considerable, irregulieres, rapides, et coupees de vallons escarpes. Ses couches, generalement epaisses, ne sont point de niveau, mais tres-inclinees a l’horizon, paralleles, pour la plupart, a la direction de la chaine, qui est aussi ordinairement celle de la bande schisteuse;–au lieu que du cote de l’orient les couches calcaires sont au sens de la chaine en direction plus ou moins approchante de l’angle droite. L’on trouve dans ces hautes montagnes calcaires de frequentes grottes et cavernes tres-remarquables, tant par leur grandeur que par les belles congelations et crystallizations stalactiques dont elles s’ornent. Quelques-unes de ces grottes ne peuvent etre attribuees qu’a quelque bouleversement des couches; d’autres semblent devoir leur origine a l’ecoulement des sources souterraines qui ont amolli, ronge et charrie une partie de la roche qui en etoit susceptible.
“En s’eloignant de la chaine, on voit les couches calcaires s’aplanir assez rapidement, prendre une position horizontale, et devenir abondantes en toute forte de coquillages, de madrepores, et d’autres depouilles marines. Telles on les voit par-tout dans les vallees les plus basses qui se trouvent aux pieds des montagnes (comme aux environs de la riviere d’Oufa); telles aussi, elles occupent tout l’etendue de la grande Russie, tant en collines qu’en plat pays; solides tantot et comme semees de productions marines; tantot toutes composees de coquilles et madrepores brisees, et de ce gravier calcaire qui se trouve toujours sur les parages ou la mer abonde en pareilles productions; tantot, enfin, dissoutes en craie et en marines, et souvent entremelees de couches de gravier et de cailloux roules.”
How valuable for science to have naturalists who can distinguish properly what they see, and describe intelligibly that which they distinguish. In this description of the strata, from the chain of mountains here considered as primitive, to the plains of Russia, which are supposed to be of a tertiary formation, our naturalist presents us with another species of strata, which he has distinguished, on the one hand, in relation to the mountains at present in question, and on the other, with regard to the strata in the plains, concerning which there is at present no question at all. Now, let us see how these three things are so connected in their nature, as to form properly the contiguous links of the same chain.
The primary and tertiary masses are bodies perfectly disconnected; and, without a medium by which they might be approached, they would be considered as things differing in all respects, consequently as having their origins of as opposite a nature as are their appearances. But the nature and formation of those bodies are not left in this obscurity; for, the secondary masses, which are interposed, participate so precisely of what is truly opposite and characteristic in the primary and tertiary masses, that it requires nothing more than to see this distinction of things in its true light, to be persuaded, that in those three different things we may perceive a certain gradation, which here takes place among the works of nature, and forms three steps distinguishable by a naturalist, although in reality nothing but the variable measure of similar operations.
We are now to assimilate the primary and tertiary masses, which are so extremely different, by means of the secondary masses, which is the mean. The primary and tertiary differ in the following respects: The one of these contains the relicts of organised bodies which are not observed in the other. But in the species containing these distinguishable bodies, the natural structure and position of the mass is little affected, or not so much as to be called into doubt. This, however, is not the case with the other; the species in which organised bodies do not appear, is in general so indurated or consolidated in its structure, and changed in its position, that this common origin of those masses is by good naturalists, who have also carefully examined them, actually denied. Now, the secondary masses may be considered, not only as intermediate with respect to its actual place, as M. Pallas has represented it, but as uniting together the primary and tertiary, or as participating of the distinguishing characters of the other two. It is homologated with the primitive mountains, in the solidity of its substance and in the position of its strata; with the tertiary species, again, in its containing marks of organised bodies. How far this view of things is consistent with the theory of the earth now given, is submitted to the consideration of the unprejudiced.
Let us see what our learned author has said farther on this subject, (page 65).
“Je dois parler d’un ordre de montagnes tres-certainement posterieur aux couches marines, puisque celles-ci, generalement lui servent de base. On n’a point jusqu’ici observe une suite de ces _montagnes tertiaires_, effet des catastrophes les plus modernes de notre globe, si marquee et si puissante, que celle qui accompagne la chaine Ouralique ou cote occidentale fur tout la longueur. Cette suite de montagnes, pour la plupart composees de grais, de marnes rougeatres, entremelees de couches diversement mixtes, forme une chaine par-tout separee par une vallee plus ou moins large de la bande de roche calcaire, dont nous avons parle. Sillonnee et entrecoupee de frequens vallons, elles s’eleve souvent a plus de cent toises perpendiculaires, se repand vers les plaines de la Russie en trainees de collines, qui separent les rivieres, en accompagnant generalement la rive boreale ou occidentale, et degenere enfin en deserts sableux qui occupent de grands espaces, et s’etendent surtout par longues bandes paralleles aux principales traces qui suivent les cours des rivieres. La principale force de ces montagnes tertiaires est plus pres de la chaine primitive par-tout le gouvernement d’Orenbourg et la Permie, ou elle consiste principalement en grais, et contient un fond inepuisable de mines de cuivre sableuses, argileuses, et autres qui se voient ordinairement dans les couches horizontales. Plus loin, vers la plaine, sont des suites de collines toutes marneuses, qui abondent autant en pierres gypseuses, que les autres en minerais cuivreux. Je n’entre pas dans le detail de celles-ci, qui indiquent sur-tout les sources salines; mais je dois dire des premieres, qui abondent le plus et dont les plus hautes elevations des plaines, meme celle de Moscou, sont formees, qu’elles contiennent tres-peu de traces de productions marines, et jamais des amas entiers de ces corps, tels qu’une mer reposee pendant des siecles de suite a pu les accumuler dans les bancs calcaires. Rien, au contraire, de plus abondant dans ces montagnes de grais stratifie sur l’ancien plan calcaire, que des troncs d’arbres entieres et des fragmens de bois petrifie, souvent mineralise par le cuivre ou le fer; des impressions de troncs de palmires, de tiges de plantes, de roseau, et de quelques fruits etrangers; enfin des ossemens d’animaux terrestres, si rares dans les couches calcaires. Les bois petrifies se trouvent jusques dans les collines de sable de la plaine; l’on en tire, entr’autres, des hauteurs sablonneuses aux environs de Sysran sur la Volga, changes en queux tres-fin, qui a conserve jusqu’a la texture organique du bois, et remarquables sur-tout par les traces tres-evidentes de ces vers rongeurs qui attaquent les vaisseaux, les pilotis et autres bois trempes dans la mer, et qui sont proprement originaires de la mer des Indes.”
This philosopher has now given us a view of what, according to the present fashion of mineral philosophy, he has termed _montagnes primitives, secondaires, et tertiaires_. The first consists in masses and strata, much indurated and consolidated, and greatly displaced in their position; but the character of which is chiefly taken from this, that they contain not any visible mark of animal or vegetable bodies.
The second are formed in a great measure of marine productions, are often no less consolidated than those of the first class, and frequently no less changed in their natural shape and situation.
The third again have for character, according to this learned theorist, the containing of those organised bodies which are proper to the earth, instead of those which in the second class had belonged to the sea; in other respects, surely there is no essential difference. It is not pretended that these tertiary strata had any other origin, than that of having been deposited in water; it is not so much as suspected, that this water had been any other than that of the sea; the few marine bodies which M. Pallas here acknowledges, goes at least to prove this fact: and with regard to the mineral operations which had been employed in consolidating those water formed strata, it is impossible not to be convinced that every effect visible in the other two are here also to be perceived.
From this view of mineral bodies, taken from the extensive observations of the Russian dominions, and from the suppositions of geologists in relation to those appearances, we should be led to conclude that the globe of this earth had been originally nothing but an ocean, a world containing neither plant nor animal to live, to grow and propagate its species. In following a system founded on those appearances, we must next suppose, that to the sterile unorganised world there had succeeded an ocean stored with fish of every species. Here it would be proper to inquire what sustained those aquatic animals; for, in such a system as this, there is no provision made for continuing the life even of the individuals, far less of feeding the species while, in an almost infinite succession of individuals, they should form a continent of land almost composed of their _exuviae_.
If fish can be fed upon water and stone; if siliceous bodies can, by the digesting powers of animals, be converted into argillaceous and calcareous earths; and if inflammable matter can be prepared without the intervention of vegetable bodies, we might erect a system in which this should be the natural order of things. But to form a system in direct opposition to every order of nature that we know, merely because we may suppose another order of things different from the laws of nature which we observe, would be as inconsistent with the rules of reasoning in science, by which the speculations of philosophy are directed, as it would be contrary to common sense, by which the affairs of mankind are conducted.
Still, however, to pursue our visionary system, after a continent had been formed from the relicts of those animals, living, growing, and propagating, during an indefinite series of ages, plants at last are formed; and, what is no less wonderful, those animals which had formed the earth then disappear; but, in compensation, we are to suppose, I presume, that terrestrial animals began. Let us now reason from those facts, without either constraining nature, which we know, or forming visionary systems, with regard to things which are unknown. It would appear, that at one period of time, or in one place, the matter of the globe may be deposited, in strata, without containing any organised bodies; at another time, or in another place, much animal matter may be deposited in strata, without any vegetable substance there appearing; but at another period, or at another time, strata may be formed with much vegetable matter, while there is hardly to be observed any animal body. What then are we to conclude upon the whole? That nature, forming strata, is subject to vicissitudes; and that it is not always the same regular operation with respect to the materials, although always forming strata upon the same principles. Consequently, upon the same spot in the sea, different materials may be accumulated at different periods of time, and, conversely, the same or similar materials may be collected in different places at the same time. Nothing more follows strictly from the facts on which we now are reasoning; and this is a conclusion which will be verified by every appearance, so far as I know.
Of this I am certain, that in a very little space of this country, in many places, such a course of things is to be perceived. Nothing so common as to find alternated, over and over again, beds of sand-stone without animal bodies, beds of coal and schistus abounding with vegetable bodies, beds of lime-stone formed of shells and corals, and beds or particular strata of iron-stone containing sometimes vegetable sometimes animal bodies, or both. Here, indeed, the strata are most commonly inclined; it is seldom they are horizontal; consequently, as across the whole country, all the strata come up to the day, and may be seen in the beds of our rivers, we have an opportunity of observing that great variety which is in nature, and which we are not able to explain. This only is certain, from what we see, that there is nothing formed in one epoch of nature, but what has been repeated in another, however dissimilar may be the operations which had intervened between those several epochs.
It must not be alleged, that the heights of the Oural mountains, or the hardness of their rocks, make an essential distinction between them and the argillaceous or arenaceous strata of the plains; solidity and hardness, as well as changes in their height and natural position, has been superinduced in operations posterior to the collection of those masses,–operations which may be formed in various degrees, even in the different parts of the same mass. If this is the case, there can be no difficulty in conceiving a stratum, which appears to be argillaceous or marly in the plains, to be found jasper in the Oural mountains. But there is nothing in the Oural mountains, that may not be found some where or other in the plains, although the soft and easily decomposing argillaceous strata be not found upon the Oural mountains, or the Alps, for this reason, that had those mountains been formed of such materials, there had not been a mountain there at this day.
But surely the greatest possible error, with regard to the philosophy of this earth, would be to confound the sediment of a river with the strata of the globe; bodies deposited upon the surface of the earth, with those sunk at the bottom of the sea; and things which only form the travelled or transported soil, with those which constitute the substratum or the solid earth. How far M. Pallas has committed this oversight, I leave others to determine. After mentioning those strata in which wood is found petrified, and metallic minerals formed, he thus proceeds, (page 69).
“Dans ces memes depots sableux et souvent limoneux, gisent les restes des grands animaux de l’Inde: ces ossemens d’elephans, de rhinoceros, de buffles monstrueux, dont on deterre tous les jours un si grand nombre, et qui font l’admiration des curieux. En Siberie, ou l’on a decouvert le long de presque toutes les rivieres ces restes d’animaux etrangers, et l’ivoire meme bien conserve en si grande abondance, qu’il forme un article de commerce, en Siberie, dis je, c’est aussi la couche la plus moderne de limon sablonneux qui leur sert de sepulture, et nulle part ces monumens etrangers sont si frequens, qu’aux endroits ou la grande chaine, qui domine surtout la frontiere meridionale de la Siberie, offre quelque depression, quelque ouverture considerable.
“Ces grands ossemens, tantot epars tantot entasses par squelettes, et meme par hecatombes, consideree dans leurs sites naturels, m’ont sur-tout convaincu de la realite d’un deluge arrive sur notre terre, d’une catastrophe, dont j’avoue n’avoir pu concevoir la vraisemblance avant d’avoir parcouru ces places, et vu, par moi-meme, tout ce qui peut y servir de preuve a cet evenement memorable[24]. Une infinite de ces ossemens couches dans des lits meles de petites tellines calcinees, d’os de poissons, de glossopetres, de bois charges d’ocre, etc. prouve deja qu’ils ont ete transportes par des inondations. Mais la carcasse d’un rhinoceros, trouve avec sa peau entiere, des restes de tendons, de ligamens, et de cartilages, dans les terres glacees des bords du Viloui, dont j’ai depose les parties les mieux conservees au cabinet de l’Academie, forme encore une preuve convaincante que ce devait etre un mouvement d’inondation des plus violens et des plus rapides, qui entraina jadis ces cadavres vers nos climats glaces, avant que la corruption eut le tems, d’en detruire les parties molles. Il seroit a souhaiter qu’un observateur parvint aux montagnes qui occupent l’espace entre les fleuves Indighirka et Koylma ou selon le rapport des chasseurs, de semblables carcasses d’elephans et d’autres animaux gigantesques encore revetues de leurs peaux, ont ete remarquees a plusieurs reprises.”
[Note 24: Voyez le Memoire, imprime dans le XVII. volume des nouveaux Commentaires de l’Academie Imperiale de Petersbourgh.]
The question here turns upon this, Are the sea shells and glossopetrae, which are thus found deposited along with those skeletons, in their natural state, or are they petrified and mineralised. If the productions of the sea shall here be found collected along with bodies belonging to the surface of the earth, and which had never been within the limits of the sea, this would surely announce to us some strange catastrophe, of which it would be difficult, perhaps, to form a notion; if, on the contrary, those marine productions belong to the solid strata of the earth, in the resolution or decay of which they had been set at liberty, and were transported in the floods, our author would have no reason from those appearances to conclude, there had existed any other deluge than those produced by the waters of the land[25].
[Note 25: Since writing this, I find my doubts in a great measure resolved, in reading M. Pallas’s Journal, translated from the German by M. Gauthier de la Peyronie. What I had suspected is, I think, confirmed in the distinct account which M. Pallas has given of those occasions in which the bones of land animals and marine objects are found buried together. The marine objects are mineralised; consequently, they have proceeded from the decomposition of the solid strata; and, having been travelled in the running water of the surface of the earth, they must have been deposited in those beds of rivers, which now are dry, alongst with the bones, or the entire bodies of terrestrial animals, the remains of which are now found there. This argument, from the state of those marine bodies will not be allowed, perhaps by the generality of mineralists, who attribute to the operations of water every species of petrifaction or mineralisation; but, until some species of proof be given with regard to the truth of that theory, which vulgar error first suggested, I must reason from a theory, in proof of which I have given clear examples, and, I think, irrefragable arguments, which shall be more and more illustrated. Thus may be removed the necessity of a general deluge, or any great catastrophe, in order to bring together things so foreign to each other; but at the same time we would ascertain this fact, That formerly the Elephant and Rhinoceros had lived in Siberia. (See Voyage de Pallas, Tom. II. p. 377 and 403.)]
Having thus endeavoured to remove this prevailing prejudice, of there being primitive parts in this earth, parts of which the composition and constitution are not to be explained upon the principles of natural philosophy, it will be proper to inquire, how far there may be in the theory, which has now been given, principles by which may be explained those appearances that have led natural philosophers to form conclusions, of there being in this earth parts whose origin may not be traced; and of there being parts whose origin may not be explained upon the same principles which apply so well to all the rest.
CHAP. V.
Concerning that which may be termed the Primary Part of the Present Earth.
In the present theory, it is maintained, that there is no part of the earth which has not had the same origin, so far as this consists in that earth being collected at the bottom of the sea, and afterwards produced, as land, along with masses of melted substances, by the operation of mineral causes. But, though all those things be similar, or equal, as to the manner of their production, they are far from being so with regard to the periods of their original composition, or to the subsequent operations which they may have undergone.
There is a certain order established for the progress of nature, for the succession of things, and for the circulation of matter upon the surface of this globe; and, the order of time is associated with this change of things. But it is not in equal portions that time is thus combined with dissimilar things, nor always found, in our estimation, as equally accompanying those which we reckon similar. The succession of light and darkness is that which, in those operations, appears to us most steady; the alternation of heat and cold comes next, but not with equal regularity in its periods. The succession of wet and dry upon the surface of the earth, though equally the work of nature and the effect of regular causes, is often to us irregular, when we look for equal periods in the course of things which are unequal. It is by equalities that we find order in things, and we wish to find order every where.
The present object of our contemplation is the alternation of land and water upon the surface of this globe. It is only in knowing this succession of things, that natural appearances can be explained; and it is only from the examination of those appearances, that any certain knowledge of this operation is to be obtained. But how shall we acquire the knowledge of a system calculated for millions, not of years only, nor of the ages of man, but of the races of men, and the successions of empires? There is no question here with regard to the memory of man, of any human record, which continues the memory of man from age to age; we must read the transactions of time past, in the present state of natural bodies; and, for the reading of this character, we have nothing but the laws of nature, established in the science of man by his inductive reasoning.
It has been in reasoning after this manner, that I have endeavoured to prove, that every thing which we now behold, of the solid parts of this earth, had been formerly at the bottom of the sea; and that there is, in the constitution of this globe, a power for interchanging sea and land. If this shall be admitted as a just view of the system of this globe, we may next examine, how far there are to be found any marks of certain parts of our earth having more than once undergone that change of posture, or vicissitude of things, and of having had reiterated operations of the mineral kingdom changing their substance, as well as altering their positions in relation to the atmosphere and sea.
Besides the gradual decay of solid land, exposed to the silent influences of the atmosphere, and to the violent operations of the waters moving upon the surface of the earth, there is a more sudden destruction that may be supposed to happen sometimes to our continents of land. In order to see this, it must be considered, that the continents of our earth are only raised above the level of the sea by the expansion of matter, placed below that land, and rarified in that place: We may thus consider our land as placed upon pillars, which may break, and thus restore the ancient situation of things when this land had been originally collected at the bottom of the ocean. It is not here inquired by what mechanism this operation is to be performed; it is certainly by the exertion of a subterranean power that the land is elevated from the place in which it had been formed; and nothing is more natural than to suppose the supports of the land in time to fail, or be destroyed in the course of mineral operations which are to us unknown. In that case, whatever were remaining of that land, which had for millions of ages past sustained plants and animals, would again be placed at the bottom of the sea; and strata of every different species might be deposited again upon that mass, which, from an atmospheric situation, is now supposed to be lower than the surface of the sea.
Such a compound mass might be again resuscitated, or restored with the new superincumbent strata, consolidated in their texture and inclined in their position. In that case, the inferior mass must have undergone a double course of mineral changes and displacement; consequently, the effect of subterranean heat or fusion must be more apparent in this mass, and the marks of its original formation more and more obliterated.
If, in examining our land, we shall find a mass of matter which had been evidently formed originally in the ordinary manner of stratification, but which is now extremely distorted in its structure, and displaced in its position,–which is also extremely consolidated in its mass, and variously changed in its composition,–which therefore has the marks of its original or marine composition extremely obliterated, and many subsequent veins of melted mineral matter interjected; we should then reason to suppose that here were masses of matter which, though not different in their origin from those that are gradually deposited at the bottom of the ocean, have been more acted upon by subterranean heat and the expanding power, that is to say, have been changed in a greater degree by the operations of the mineral region. If this conclusion shall be thought reasonable, then here is an explanation of all the peculiar appearances of the alpine schistus masses of our land, those parts which have been erroneously considered as primitive in the constitution of the earth.
We are thus led to suppose, that some parts of our earth may have undergone the vicissitudes of sea and land more than once, having been changed from the summit of a continent to the bottom of the sea, and again erected, with the rest of that bottom, into the place of land. In that case, appearances might be found to induce natural philosophers to conclude that there were in our land primary parts, which had not the marine origin which is generally to be acknowledged in the structure of this earth; and, by finding other masses, of marine origin, superincumbent upon those primary mountains, they might make strange suppositions in order to explain those natural appearances.
Let us now see what has been advanced by those philosophers who, though they term these parts of the earth _primordial_, and not _primitive_, at the same time appear to deny to those parts an origin analogous to that of their secondary mountains, or strata that are aquiform in their construction.
M. de Luc, after having long believed that the strata of the Alps had been formed like those of the low countries, at the bottom of the sea, gives an account of the occasion by which he was first confirmed in the opposite opinion.[26] Like a true philosopher, he gives us the reason of this change.
[Note 26: Lettres Physique et Morales sur l’Histoire de la Terre, tom. 2. pag. 206.]
“Ce fut une espece de _montagne_ tres commune, et que j’avois souvent examinee qui dessilla mes yeux. La pierre qui la compose est de la classe appellee _schiste_; son caractere generique est d’etre _feuilletee_; elle renferme _l’ardoise_ dont on couvre les toits. Ces _feuillets_ minces, qu’on peut prendre pour des _couches_, et qui le font en effet dans quelques pierres de ce genre, rappelloient toujours l’idee vague de depots des eaux. Mais il y a des masses dont la composition est plutot par fibres que par feuillets, et dont le moellon ressemble aux copeaux de bois d’un chantier. Le plus souvent aussi les feuillets sont situes en toute suite de sens dans une meme _montagne_, et quelquefois meme verticalement, Enfin il s’en trouve de si tortilles, qu’il est impossible de les regarder comme des depots de l’eau.
“Ce fut donc cette espece de montagne qui me persuada la premiere que toutes les montagnes n’avoient pas une meme origine. Le lieu ou j’abjurai mon erreur, etoit un de ces grands _chantiers_ petrifies, qui, par la variete du tortillement, et des zig-zags des fibres du moellon qui le composoit, attira singulierement mon attention. C’etoit un sort grand talus qui venoit d’une face escarpee; j’y montai pour m’approcher du rocher, et je remarquai, avec etonnement, des multitudes de paquets enchevetres les uns dans les autres, sans ordre ni direction fixe; les uns presqu’en rouleaux; les autres en zig-zag; et meme ce qui, separe de la montagne, eut peu etre pris pour des _couches_, le trouvoit incline de toute maniere dans cette meme face de rocher. _Non_, me dis-je alors a moi-meme; _non, l’eau n’a pu faire cette montagne…. Ni celle-la donc_, ajoutai-je en regardant ailleurs…. _Et pourquoi mieux celle-la? Pourquoi toutes les montagnes devroient-elles etre le produit des eaux, seulement parce qu’il y en a quelques-unes qui annoncent cette origine_? En effet, puis qu’on n’a songe aux eaux, comme cause des montagnes, que par les preuves evidentes que quelques-unes offroient de cette formation; pourquoi etendre cette consequence a toutes, s’il y en a beaucoup qui manquent de ces caracteres? C’est comme le dit Mr. d’Alembert, qu’on generalise ses premieres remarques l’instant d’apres qu’on ne remarquoit rien.”
Science is indebted to this author for giving us so clear a picture of natural appearances, and of his own reasoning upon those facts, in forming his opinion; he thus leads astray no person of sound judgment, although he may be in error. The disposition of things in the present case are such, that, reasoning from his principles, this author could not see the truth; because he had not been persuaded, that aquiform strata could have been so changed by the chemical power of fusion, and the mechanical force of bending while in a certain state of softness.
But though, in this case, the reasoning of this philosopher is to be justified, so far as he proceeded upon principles which could not lead him to the truth, his conduct is not so irreproachable in applying them to cases by which their fallacy might have been detected. This author acknowledges calcareous strata to be aquiform in their original; but, in those mountains which he has so much examined, he will find those aquiform bodies have undergone the same species of changes, which made him conclude that those schistus mountains had not been truly aquiform, as he at first had thought them. This would have led him to reason back upon his principles, and to say, _If one species of strata may be thus changed in its texture, and its shape, may not another be equally so? Therefore, may not the origin of both be similar_?
But least I should do injustice to this author, to whom we are indebted for many valuable observations in natural history, I shall transcribe what he has said upon the subject, being persuaded that my readers will not think this improper in me, or impertinent to the argument.
“Quand nous fumes une fois persuades que la mer n’avoit pas fait toutes les _montagnes_, nous entreprimes de decouvrir les caracteres distinctifs de celles qui lui devoient leur origine; et s’il etoit, par exemple, des matieres qui leur fussent propres. Mais nous y trouvames les memes difficultes qu’on rencontre dans tout ce qu’on veut classer dans la nature. On peut bien distinguer entr’elles les choses qui ont fortement l’empreinte de leur classe; mais les confins echappent toujours.
“C’est la, pour le dire en passant, ce qui a pu conduire quelques philosophes a imaginer cette _chaine des etres_ ou ils supposent, que, de la pierre a l’homme et plus haut, les nuances sont reellement imperceptibles. Comme si, quoique les limites soyent cachees a nos sens, notre intelligence ne nous disoit pas, qu’il y a un _saut_, une distance meme infinie, entre le plus petit degre d’organization _propageante_, et la matiere unie par la simple cohesion: entre le plus petit degre de _sensibilite_, et la matiere insensible: entre la plus petite capacite d’observer et de transmettre ses observations, et l’instinct constamment le meme dans l’espece. Toutes ces differences tranchees existent dans la nature; mais notre incapacite de rien connoitre a fond, et la necessite ou nous sommes de juger de tout sur des apparences, nous fait perdre presque toutes les limites, parce que sur ces bords, la plupart des phenomenes sont equivoques. Ainsi la plante nous paroit se rapprocher de la pierre, mais n’en approche jamais reellement.
“On eprouve la meme difficulte a classer les montagnes; et quoique depuis quelque tems plusieurs naturalistes ayent aussi observe qu’elles n’ont pas toutes la meme origine, je ne vois pas qu’on soit parvenu a fixer des caracteres infaillibles, pour les placer surement toutes dans leurs classes particulieres.
“Apres avoir examine attentivement cet objet, d’apres les phenomenes que j’ai moi-meme observes, et ce que j’ai appris par les observations des autres; j’ai vu que c’etoit la un champ tres vaste, quand on vouloit l’embrasser en entier, et trop vaste pour moi, qui n’etoit pas libre d’y consacrer tout le tems qu’il exige. Je me suis donc replie sur mon objet principal, savoir _la cause qui a laisse des depouilles marines dans nos continens_, et l’examen des hypotheses sur cette matiere.
“Les phenomenes ainsi limites, se reduisent a ceci: qu’il y a dans nos continens des montagnes visiblement formees par des _depots successifs de la mer_ et a l’egard des quelles il n’y a besoin de rien imaginer, si ce n’est la maniere dont elles en sont sorties: qu’il y en a d’autres au contraire, qui ne portent aucun des caracteres de cette cause, et qui, si elles ont ete produites dans la _mer_, doivent etre l’effet de toute autre cause que de simples depots successifs, et avoir meme precede l’existence des animaux marins. J’abandonne donc les classes confuses ou ces caracteres sont equivoques, jusqu’a ce qu’elles servent a fonder quelque hypothese; ayant assez de ces deux classes tres distinctes pour examiner d’apres elles tous les systemes qui me sont connus.
“La ou ces deux classes de montagnes sont melees, on remarque que celles qui sont formees par _couches_, et qui renferment des _corps marins_, recouvrent souvent celles de l’autre classe, mais n’en sont jamais recouvertes. On a donc naturellement conclu, que lors meme que la _mer_ auroit en quelque part a la formation des montagnes ou l’on ne reconnoit pas son caractere, celles auxquelles elle a travaille seule, en enlevant des matieres dans certaines parties de son fond et les deposant dans d’autres, font au moins les dernieres formees. On les a donc nommees _secondaires_, et les autres _primitives_.
“J’adopterai la premiere de ces expressions; car c’est la meme qui nous etoit venu a l’esprit a mon frere, et a moi longtemps avant que nous l’eussions vue employer; mais je substituerai celle de _primordiales a_ _primitives_ pour l’autre classe de _montagnes_, afin de ne rien decider sur leur origine. Il est des _montagnes_, dont jusqu’a present on n’a pu demeler la cause: voila le fait. Je ne dirai donc pas qu’elles ont ete creees ainsi, parce qu’en physique je ne dois pas employer des expressions sur lesquelles on ne s’entend pas. Sans doute cependant, que l’histoire naturelle ni la physique ne nous conduisent nullement a croire que notre globe ait existe de toute eternite; et lorsqu’il prit naissance, il fallut bien que la matiere qui le composa fut de quelque nature, ou sous quelque premiere forme integrante. Rien donc jusqu’ici n’empeche d’admettre que ces _montagnes_ que je nommerai _primordiales_, ne soient reellement _primitives_; je penche meme pour cette opinion a l’egard de quelques unes. Mais il y a une tres grande variete entr’elles; et quoiqu’elles soyent toutes egalement exclues de la classe _secondaire_, elles ne sont pas toutes semblables: il y en a meme un grand nombre dont les matieres ont une certaine configuration qui semble annoncer qu’elles ayent ete molles et durcies ensuite, quoique par une toute autre cause que celle qui a agi pour former les montagnes secondaires.”
Here I would beg leave to call the attention of philosophers to this observation of a naturalist who explains all petrification, and the consolidation of strata by aqueous infiltration. If he has here found reason to conclude that, in those primordial parts of the earth, there are a great number which, from their present configuration, must have been in a soft state and then hardened, and this by a quite different cause from that which he supposes had produced the consolidation and hardness of the secondary parts; this is entering precisely into my views of the subject, in ascribing all the consolidation of the earth, whether primary or secondary, to one general cause, and in tracing this cause, from its effects, to be no other than the fusion of those bodies. It must be evident, that if this philosopher has seen good reason for concluding such a softening cause, which had operated upon the primary parts, to be quite different from that which he ascribes to the consolidation of the secondary, which is the effect of water, it must then, I say, be evident that the softening cause of the primary parts, if not heat, by which every degree of fusion may be produced, must be an occult cause, one which cannot be admitted into natural philosophy.
By thus choosing to consider mountains as of two distinct kinds, one aquiform which is understood, and the other primordial which is not to be known, we supersede the necessity of reconciling a theory with many appearances in nature which otherwise might be extremely inconvenient to our explanation, if not inconsistent with our system. Our author no doubt has thus relieved himself from a considerable difficulty in the philosophy of this earth, by saying here is a great part which is not to be explained. But I would beg leave to observe, that this form of discussion, with regard to a physical subject, is but a mere confession of our ignorance, and has no tendency to clear up another part of the subject of which one treats, however it may impress us with a favourable opinion of the theorist, in allowing him all the candour of the acknowledgement.
The general result of the reasoning which we now have quoted, and what follows in his examination, seems to terminate in this; that there are various different compositions of mountains which this author cannot allow to be the production of the sea; but it is not upon account of the matter of which they are formed, or of the particular mixture and composition of those species of matter, of which the variety is almost indefinite. According to this philosopher, the distinction that we are to make of those primordial and secondary competitions, consists in this, that the first are in such a shape and structure as cannot be conceived to be formed by subsidence in water.
M. de Saussure has carefully examined those same objects; and he seems inclined to think that they must have been the operation of the ocean; not in the common manner of depositing strata, but in some other way by crystallization. The present theory supposes all those masses formed originally in the ordinary manner, by the deposits or subsidence of materials transported in the waters, and that those strata were afterwards changed by operations proper to the mineral regions.
But the subject of the present investigation goes farther, by inquiring if, in the operations of the globe, a primary and secondary class of bodies may be distinguished, so far as the one may have undergone the operations of the globe, or the vicissitudes of sea and land, oftener than the other, consequently must be anterior to the later productions both in time and operation, although the original of all those bodies be the same, and the operations of the earth, so far as we see in the effects, always proceed upon the same principles. This is an extensive view of nature to which few have turned their thoughts. But this is a subject to which the observations described by this author have evidently a reference.
In his 113th letter, he has given us a view of one of those parts of the earth that are proper to be examined in determining this question so important in the genealogy of land, although no ways concerned in altering the principles upon which nature in forming continents must proceed.
It is in describing the nature of the mountains about _Elbingerode_; and he begins in ascending from Hefeld.
“Cette partie exterieure de la chaine est _primordiale_: c’est du _granit_ a _Hereld_ et au commencement de la route; puis quand on passe dans d’autres vallees, on trouve les _schistes_ et la _roche grise_ dans tout le pied des montagnes: mais des qu’on est arrive a une certain hauteur, on voit de la _pierre a chaux_ par couches etendue sur ces matieres; et c’est elle qui forme le sommet de ces memes montagnes; tellement que la plaine elevee, qui conduit a _Elbingerode_, est entierement de _pierre a chaux_, excepte dans sa partie la plus haute ou cette pierre est recouverte des memes _gres_ et sables _vitrescibles_ qui sont sur le schiste du Bruchberg et sur la _pierre a chaux_ dans la _Hesse_ et le pays de Gottingue.
“Les environs d’Elbingerode etant plus bas que ces parties recouvertes de matieres vitrescibles, montrent la _pierre a chaux_ a nud; et l’on y trouve de tres beaux marbres, dont les nuances jaunes, rouges et vertes sont souvent tres vives, et embellies par les coupes des _corps marins_.
“Cependant le schiste n’est pas enseveli partout sous ces depots de la mer; on le retrouve en quelques endroits, et meme avec de _filons_.
“Ainsi au milieu de ces matieres _calcaires_ qui forment le sol montueux des environs _d’Elbingerode_, paroit encore le _schiste_ sur lequel elles ont ete deposees: Et en montant a la partie la plus elevee de ces memes environs, on trouve que la _pierre a chaux_ est recouverte elle-meme d’une _pierre sableuse_ grise par couches, dans laquelle on voit quantite de petits fragmens de _schiste_ poses de plat. C’est la que se trouve une des mines de _fer_ dont le minerai va en partie a la _Koningshutte_, mais en plus grande partie a la _Rothechutte_, qui n’est qu’a une lieue de distance. On perce d’abord la couche sableuse; sous elle se trouve de la _pierre a chaux_ grise; puis une couche de _pierre a chaux ferrugineuse_, remplie de _corps marins_, et surtout _d’entroques_: C’est cette _couche_ qui est ici le _minerai_; et elle appartient a la formation de cette eminence comme toutes les autres _couches_. Cette mine se nomme _bomshey_: elle n’est pas riche; mais elle sert de _fondant_ aux matieres ferrugineuses tirees des filons des montagnes primordiales en meme tems qu’elle leur ajoute son _fer_ dans la fonte. A quelque distance de la on a perce un autre puits; qui a transverse d’abord une sorte de pierre, que je ne saurois nommer, mais qui ressemble fort a une _lave_ poreuse. Au dessous de cette couche on a retrouve la _pierre a chaux_ ordinaire; puis la _couche ferrugineuse_ y continue; mais elle differe un peu de ce qu’elle est dans l’autre mine, une partie de sa substance etant convertie en _jaspe_.
“Mais ce qui est digne de la plus grande attention dans cette contree, est un filon peu distant nomme _Buchenberg_, qui appartient en partie au Roi, et en partie a Mr. le Comte de _Wernigerode_. La montagne en cette endroit montre une vallee artificielle de 70 a 80 pieds de profondeur, de 20 a 30 de largeur dans le haut, et de 400 toises en etendue. C’est le creusement qu’on a deja fait en suivant ce _filon_ de _fer_, que l’on continue a exploiter de la meme maniere sur les terres de Mr. le Comte de _Wernigerode_. La matiere propre de la montagne _est_ de _schiste_; et la vallee qui se forme de nouveau a mesure qu’on enleve la _gangue_ du _filon_, a surement deja existe dans la mer sous la forme d’une _fente_, qui a ete remplie, et en particulier des ingrediens dont on fait aujourd’hui le _fer_.”
Here is a supposition of our author that corresponds to nothing which has yet been observed any where else, so far as I know. It is concerning a mineral vein, one which does not appear to differ in any respect from other mineral veins, except in being worked in that open manner which has given our author an idea of its being a valley. He then supposes that valley (or rather empty vein) to have been in this mountain when at the bottom of the sea, and that this mineral vein had then been filled with those materials which now are found in that space between the two sides of the separated rock. This is a very different operation from that of infiltration, which is commonly supposed to be the method of filling mineral veins; but, we shall soon see the reason why our author has here deserted the common hypothesis, and has adopted another to serve the occasion, without appearing to have considered how perfectly inconsistent those two suppositions are to each other. That mineral veins have been filled with matter in a fluid state, is acknowledged by every body who has either looked at a mineral vein in the earth, or in a cabinet specimen; mineralists and geologists, in general, suppose this to have been done by means of solutions and concretions, a supposition by no means warranted by appearances, which, on the contrary, in general demonstrate that the materials of those veins had been introduced in the fluid state of fusion. But here is a new idea with regard to the filling of those veins; and, I would now beg the reader’s attention to the facts which follow in this interesting description, and which have suggested that idea to our author.
“Quand cette matiere accidentelle est enlevee, on voit la coupe du _schiste_ des deux cotes de la _fente_, faisant un _toit_ et un _mur_, parce que la _fente_ n’est pas absolument verticale: des qu’il y a un peu d’inclinaison, on distingue un _toit_ et un mur, comme j’ai l’honneur de l’expliquer a V.M. On ne connoit point encore l’etendue de ce filon, ni dans sa profondeur, ou l’on ne peut pas s’enfoncer beaucoup de cette maniere, ni dans la longueur, selon laquelle on continue a l’exploiter.
“Voila donc un _filon_, a la rigueur de la definition que j’en ai donne a V.M. c’est a dire, une _fente_ dans la montagne naturelle, _comblee_ de _matiere_ etrangere. Mais ce qu’il y a d’extraordinaire ici, c’est que cette _matiere_ vient de la _mer_: ce sont differentes _couches aquiformes_, dont quelques unes sont remplies de _corps marins_. Il y a des _couches_ d’une _terre martiale_ fort brune et sans liaison: d’autres, au contraire toujours _martiales_, sont tres dures et renferment de tres beau jaspe sanguin: d’autres enfin sont de vrai _marbre_ gris veinees de rouge. C’est dans ce marbre que font les _corps marins_, savoir des coquillages et des spongites; et il est lui-meme martial comme tout le reste: les mineurs le nomment _Kubrimen_, et ne l’employent que comme un _fondant_ pour d’autres _mineraux de fer_.
“A ce _filon_, s’en joignent d’autres plus embarrassans. Ils viennent du _toit_, qu’ils divisent par de larges _fentes_ comblees, aboutissantes au _filon_ principale. Ils font de meme _calcaires_ et marins faits par _couches_; mais ces _couches_ ont une si grande inclinaison, que je ne puis les comprendre: il faut qu’il y ait eu d’etranges bouleversemens dans ces endroits-la[27].
[Note 27: Here, no doubt, are appearances which it is impossible to explain by the theory of infiltration; it is the filling of mineral veins, and their branches or ramifications, with marble containing marks of marine objects. But, if we shall suppose this marble to have been in the fluid state of fusion, as well as the iron-ore and jasper, we may easily conceive it introduced into the principal vein and its branches. The description here given of those appearances is by no means such as to enable us to judge particularly of this case, which surely merits the most accurate investigation, and which, I doubt not, will give physical demonstration of the fusion of those mineral substances. I know that shells have been found within the body of veins in Germany; but, a stratification of those materials in a vein was never heard of before, so far as I know.]
“Ces _fentes_ se sont faites, et ont ete remplies, dans la _mer_; puisque les matieres qui les remplissent sont de la classe de ses depots tres connoissables, et qu’il contiennent des _depouilles marines_. Mais ce qui embarrasse alors c’est que les autres _filons_ ne soyent pas dans le meme cas. N’est ce point la encore un indice, que ces _fentes_ out ete d’abord et principalement remplies de matieres, poussees du fond par la meme force qui secouoit les montagnes[28].
[Note 28: But what is this power by which matter is to be forced from the bottom of the sea to the top of the mountains? For, unless we can form some idea of that power which, as a cause, we ascribe to the perceived effect, we either say nothing to the purpose, or we employ a preternatural cause. It is not sufficient to imagine a power capable of raising from the bottom of the sea the materials deposited in the abyss; it is also necessary to find a power capable of softening bodies which are hard, and of thus consolidating those masses which are formed of loose or unconnected materials. Such a power, indeed, the present theory assumes; and, so far as this shall be implied in the supposition of our author, it will thus have received a certain conformation.]
“Ce _filon_ n’est pas le seul dans le _Hartz_ qui donne des signes _marins_. Il y en a un autre, qui meme se rapproche davantage de la nature du commun des _filons_, et ou l’on trouve aussi des _coquillages_. C’est celui de _Haus-Hartzbergerzug_, pres de _Clausthal_, ou, dans les _Halles_ de quelques mines de plomb abandonnees, et dans une forte _d’ardoise_, on trouve de petites _moules_ ou _tellines_ striees, d’une espece particuliere que j’ai vue dans des _ardoises secondaires d’Arotzen_ en _Waldek_ et de _Sombernon_ en _Bourgogne_. Il y a donc certainement quelques _filons_ faits par les depots de la _mer_ dans les _fentes_ de montagnes _primordiales_; comme au contraire il y a des _filons_ metalliques sans indices _marins_, dans des montagnes evidemment _secondaires_, telles que celles de _Derbyshire_, ou les _filons_ de _plomb_ traversent des couches de _pierre a chaux_.”
Here again our author seems to me to refute his own supposition, That a chasm in the schistus rock may have existed at the bottom of the sea, and been then filled from above with such materials as were transported by the moving water to that place, is not impossible; but nobody, who knows the nature of a common metallic vein, can ever suppose it to have been filled in that manner. Our author then adds, “On ne fait reellement que commencer dans ce genre d’observations, considerees quant a la Cosmologie; ainsi il ne faut point desesperer que tout cela ne se devoile un jour, et que nous n’acquerrions ainsi un peu plus de connoissance sur ce qui se passoit dans la _mer ancienne_.
“En revenant vers _Elbingerode_, nous retrouvames ces _schistes_, qui paroissent au travers des _marbres:_ ils sont donc la continuation de la masse _schisteuse_ a laquelle appartient le _filon_, dont je viens de parler. Ce _filon_ a ete forme dans une _fente_, restee ouverte et vide: les depots de la _mer_ l’ont comblee, en meme tems qu’ils formoient les couches de _marbre_, qui sont a l’exterieur. En effet, ce _filon_ contient des _couches marines ferrugineuses_, de la meme nature que celles des collines calcaires voisines formees sur le schiste.
“Nous partimes _d’Elbingerode_ dans l’apres midi pour nous rapprocher de Clausthal. Notre chemin fut encore quelque tems sur des sommites _calcaires_; et avant que d’en sortir, nous trouvames une autre mine singuliere a _Arenfeld_. C’est encore un vrai _filon_; mais dans une montagne de _pierre a chaux:_ C’est a-dire, que cette montagne a aussi ete _fendue_, et que la _fente_ a ete remplie d’une _gangue_. La matiere de ce _filon_ est encore _calcaire_ en plus grande partie; mais cette _pierre a chaux_ distincte est _ferrugineuse_, et parsemee de concretions de _jaspe_ comme celles _d’Elbingerode:_ on y trouve aussi une matiere verdatre, qui, comme le _jaspe_, ne fait pas effervescence avec l’eau forte.”
Here is a phenomenon which is altogether incompatible with the theory that this author has given us for the explanation of those appearances. He supposes empty crevices in the schistus mountains at the bottom of the sea; these crevices he supposes filled by the deposits of the sea, at the same time, and with the same materials with which the lime-stone strata were formed above the schistus mountains; but we find one of those same veins in these secondary calcareous strata. Now, tho’ we should be disposed to allow, that, in the primordial mountain, of which we are supposed not to know the origin, there might have been empty crevices which were afterwards filled with materials transported by the sea, this cannot be admitted as taking place in the loose or incoherent materials deposited above the schistus. Consequently, this theory of our author, which is evidently erroneous with regard to the veins in the lime-stone, must, in the other case, be at least examined with a jealous eye.
“Le haut de cette partie des montagnes _calcaires_ etoit encore recouvert de _sable_ et de gres _vitrescibles_: et continuant a marcher, sans aucune inflexion sensible, nous nous trouvames subitement sur les _schistes_; d’ou nous montames plus rapidement. Puis traversant quelques petites vallees nous arrivames sur les montagnes qui appartiennent au prolongement du _Brocken_ ou _Blocksberg_. La matiere dominante est alors le _granit_; mais il est tout en blocs le long de cette route, et ces blocs se trouvent a une telle distance de tout sommite intacte de cette pierre, qui est aise de juger non seulement qu’ils ne sont pas dans leur place originaire, mais encore qu’il ne sont arrives la par aucune des causes naturelles qui agissent dans les montagnes; savoir, la pesanteur, la pente, et le cours des eaux. Ce sont donc de violentes explosions qui ont disperse ces blocs; et alors ils deviennent un nouveau trait cosmologique de quelque importance: car rien ne se meut, ni ne paroit s’etre mu depuis bien des siecles, dans ces lieux qui montrent tant de desordre: un tapis de verdure couvre tout, en conservant les contours baroques du sol. Le betail ne sauroit paturer dans de telles prairies; mais l’industrieux montagnard fait y faucher[29].
[Note 29: M. de Saussure endeavours to explain those appearances of transported blocks of granite by another cause; this is a certain _debacle_ of the waters of the earth, which I do not understand. M. de Luc again attempts to explain it by violent explosions; I suppose he means those of a volcano. But he has not given us the evidence upon which such an opinion may be founded, farther than by saying that those blocks could not have come there by the natural operations of the surface. By this must be meant, that, from the nearest summit of granite, there is not, at present, any natural means by which these blocks might be transported to that place. But it is not with the present state of things that we are concerned, in explaining the operations of a distant period. If the natural operations of the surface change the shape of things, as is clearly proved by every natural appearance, Why form an argument against a former transaction, upon the circumstances of the present state of things? Our author does not seem to perceive, that, from this mode of reasoning, there is is an insuperable objection to his violent explosions having been employed in producing those effects. For, had there been such a cause, the evidence of this must have remained; if the surface of the earth does not undergo great changes: If, again, this surface be in time much changed, How can we judge from the present shape, what might have been the former posture of things?
This author, indeed, does not allow much time for the natural operations of the globe to change its surface; but, if things be not greatly removed from the state in which the violent operations of the globe had placed them, Why does he not point out to us the source of this great disorder which he there perceives? From what explosion will be explained the blocks of granite which are found upon the Jura, and which must have come from the mass of _Mont Blanc_? If these dispersed blocks of stone are to be explained by explosion, there must: have been similar explosions in other countries where there is not the smallest appearance of volcanic eruptions; for, around all our granite mountains, and I believe all others, there are found many blocks of granite, traveled at a great distance, and in all directions.]
“_Oberbruck_, ou nous avions ete la precedente fois, se trouva sur notre route, et nous y passames aussi la nuit, dans l’esperance de pouvoir monter le lendemain sur le _Brocken_; mais il fut encore enveloppe de nuages; ainsi nous continuames a marcher vers _Clausthal_, passant de nouveau par le _Bruchberg_, ou le _sable_ et ses gres recouvrent le _schiste_; puis arrivant a une autre sommite, nous y trouvames la meme pierre _sableuse_ par couches, melee de parcelles de _schiste_, que nous avions vue sur les montagnes _calcaires d’Elbingerode_. Il est donc toujours plus certain que le sol primordial de toutes ces montagnes existoit sous les eaux de l’ancienne mer; puisqu’il est recouvert de diverses fortes de depots, connus pour appartenir a la _mer_; et que les _fentes_ des _filons_ existoient dans cette _mer ancienne_; puisqu’elle en a rempli elle-meme quelques unes, et qu’elle a recouvert de ses depots quelques autres _filons_ tout formes. Quant a celles des matieres de ces _filons_, qui ne paroissent pas etre _marines_ (et c’est de beaucoup la plus grande quantite), j’ai toujours plus de penchant d’en attribuer une partie a l’operation des _feux souterreins_, a mesure que je vois diminuer la probabilite de les assigner entierement a _l’eau_. Mais quoi-qu’il en soit, ces gangues ne font pas de meme date que les montagnes[30].
[Note 30: I most willingly admit the justness of our author’s view, if he thus perceives the operation of fire in the solids of our earth; but it is not for the reasons he has given us for discovering it here more than in other places; for there is not a mineral vein, (so far at least as I have seen), in which the appearances may be explained by any thing else besides the operation of fire or fusion. It is not easy to conceive in what manner our author had conceived the opinions which he has displayed in these letters. He had no opinion of this kind, or rather he was persuaded that subterraneous fire had no hand in the formation of this earth before he came to this place of the Hartz; here he finds certain appearances, by which he is confirmed in his former opinion, that water had operated in forming mineral veins; and then he forms the idea that subterraneous fire may have operated also. But, before the discovery of the chasms in the schistus mountains having been filled with the stratified materials of the sea, How had he supposed veins to be filled? If this philosopher had before no opinion of subterraneous fire, as instrumental in that operation, How comes he now to change that former opinion? For, unless it be the extraordinary manner of filling these open crevices in the mountains by matter deposited immediately from the sea, there is certainly no other appearance in this mineral country of the Hartz, that may not be found in any other, only perhaps upon a smaller scale.]
“Le lendemain de notre arrivee a _Clausthal_, qui etoit le 13e, nous allames visiter d’autres mines de _fer_ en montagnes secondaires, situees au cote oppose du Hartz. Elles sont aupres de _Grund_ l’une des _villes de mines_, et pres du lieu ou sortira la nouvelle _galerie d’ecoulement_ a laquelle on travaille, etc.
“Arrives a _Grund_ les officiers mineurs vinrent, comme a l’ordinaire, accompagner Mons. de _Reden_ aux _mines_ de leur departement. Celles-ci, sans etre plus extraordinaires que celles qui nous avions vues a _Elbingerod_, ou sans aider mieux jusqu’ici a expliquer ce qu’elles ont toutes d’extraordinaire, nous donnent au moins des indices probables de grands accidens. Ces montagnes de _Grund_ sont encore de l’espece remarquable, dont la base est de _schiste_, et le haut de _pierre a chaux_. Les mines qu’on y exploit sont de _fer_, et se trouvent dans cette matiere _calcaire_; mais elles y sont sous des apparences tout-a-fait etranges. La montagne ou nous les vimes principalement le nomme _Iberg_. On y poursuit des masses de _pierre a fer_, de l’ensemble desquelles les mineurs ne peuvent encore se rendre compte d’une maniere claire. Ils ont trouve dans cette montagne des _ca__vernes_, qui ressemblent a l’encaissement de _sillons_ deja exploites, ou non formes; c’est-a-dire, que ce sont des _fentes_ presque verticales, et vides, Le _minerai_ qu’ils poursuivent est en _Rognons_; c’est a dire, en grandes masses sans continuite decidee. Cependant ces masses semblent se succeder dans la montagne suivant une certaine direction; tellement que les mineurs savent deja les chercher, par des indices d’habitude. La substance de cette _pierre a fer_ particuliere renferme des crystallizations de diverses especes. Il y a des _druses de quartz_, ou de petits cristaux de quartz qui tapissent des cavites; il y a aussi du _spath_ commun, et de celui qu’on nomme pesant; on y trouve enfin une forte de crystallization nommee _Eisenman_ (_homme de fer_) par les mineurs; se sont des amas de cristaux noir-atres, qui ressemblent a des groupes de grandes lentilles plattes, et ces cristaux sont _ferrugineux_.
“Entre les signes de bouleversement que renferme ce lieu, est un rocher nomme _Gebichensten_, qui est en _pierre a chaux_, ce que _l’Ebrenbreitstein_ de _Coblentz_ est en pierre sableuse: c’est-a-dire, que ses _couches_, remplies de _corps marins_, sont presque verticales; ceux de ces corps qu’on y trouve en plus grande quantite, sont des _madrepores_. Ce rocher s’eleve comme un grand obelisque, au-dessus des _cavernes_, dont j’ai parle; montrant par le cote ses _couches_, qui se trouvent, comme je l’ai dit, dans une situation presque verticale. Sa base est deja bien minee, tant par les _cavernes_, que par la _pierre a fer_ qu’on en tire; et je ne me hasardai dessus, que parce que je me dis, qu’il y a des millions contre un a parier, que ce n’est pas le moment ou il s’enfoncerait. Mais je n’en dirois pas autant, s’il s’agissoit de m’y loger a demeure.
“Quoique tout ce lieu la soit fort remarquable, il se pourrait que ce ne fut qu’un phenomene particulier. Les _cavernes_ peuvent devoir leur origine a la meme cause que celle de Schartzfeld; et le derangement des rochers superieurs a des enfoncemens occasionnes par ces _cavernes_. Rien n’est si difficile que de retracer aujourd’hui ces fortes d’accidens a cause des changemens que le tems y a operes. S’ils sont arrives sous les eaux de la _mer_, on concoit aisement les alterations qui ont du succeder; et si c’est depuis que nos continens sont a sec, les eaux encore, tant interieures qu’exterieures, et la vegetation, en ont beaucoup change l’aspect.”
This author has a theory by which he explains to himself the former residence of the sea, above the summits of our mountains; this, however, is not the theory by which we are now endeavouring to explain appearances; we must therefore be allowed to reason from our own principles, in considering the facts here set forth by our author.
Nothing, I think, is more evident, than that in this mineral country of the Hartz, we may find the clearest marks of fracture, elevation, and dislocation of the strata, and of the introduction of foreign matter among those separated bodies. All those appearances, our author would have to be nothing but some particular accident, which is not to enter into the physiology of the earth. I wish again to generalise these facts, by finding them universal in relation to the globe, and necessarily to be found in all the consolidated parts of our land.
It was not to refute our author’s reasoning that I have here introduced so much of his observations, but to give an extensive view of the mineral structure of this interesting country. This therefore being done, we now proceed to what is more peculiarly our business in this place, or the immediate subject of investigation, viz. the distinction of primary and secondary strata.
“Dans le voisinage de cette montagne, il y a une autre fort interessante, que je vis le jour suivant. Quoiqu’en traitant des volcans, j’aie demontre que la formation des montagnes, par soulevement, etoit sans exemple dans les faits, et sans fondement dans la theorie, je ne laisseroi pas de m’arreter au phenomene que presente cette montagne; parce qu’il prouvera directement que les _couches calcaires_ au moins, ont ete formees _a la hauteur ou elles sont_; c’est-a-dire qu’elles n’ont pas ete soulevees.
“Voulant prendre l’occasion de mon retour a _Hanovre_, pour traverser les avant-corps du _Hartz_, dans quelque nouvelle direction; je resolus de faire ce voyage a cheval, et de prendre ma route droite vers _Hanovre_, au-travers des collines; ce qui me conduisit encore a _Grund_ puis a _Muenchehof Brunshausen, Engelade, Winsenburg_ et _Alfeld_, ou enfin, traversant la _Leine_ j’entrai dans la grande route.
“Je quittai donc _Clausthal_ (et avec bien du regret) le 14 au matin; et revenant d’abord a _Grund_, je le laissai sur ma droite, ainsi que _l’Iberg_; et plus loin, du meme cote, une autre montagne nommee _Winterberg_ dont la base est _schiste_, et le sommet plus haut que Clausthal, entierement compose de _couches calcaires_. De _Grund_ je montai vers une montagne nommee _Ost Kamp_; et je commencai la a donner une attention particuliere au sol. Le long de mon chemin, je ne trouvai longtemps que des schistes, qui montroient leurs points en haut, comme a l’ordinaire, et avec tous leurs tortillemens de feuillets. Mais arrive au haut de la montagne, j’y vis des carrieres de _pierre a chaux_, ou les couches absolument regulieres, et qui ont peu d’epaisseur sur le _schiste_ suivent parfaitement les contours du _sommet_. Ces lits de _pierre a chaux_ n’ont certainement pas ete souleves du fond de la _mer_ sur le dos des schistes; lors meme qu’a cause de la grande inclinaison des feuillets de ceux-ci on voudroit le attribuer a quelque revolution telle que le _soulevement_; (ce que je n’admettrois point). Car si ces lits _calcaires_, ayant ete faits au fond de la _mer_, avoyent ete souleves avec les schistes, ne feroient-ils pas brises et bouleverses comme eux? Il est donc evident, que quoiqu’il soi arrive au schiste qui les porte, ces lits, et tous les autres de meme genre qui sont au haut de ces montagnes, ont ete deposees au niveau ou ils sont; et que par consequent la _mer_ les surpassoit alors. Ainsi le systeme de soulevement perd son but, s’il tend a expliquer pourquoi nous avons des _couches_, formees par la mer, qui se trouvent maintenant si fort au dessus de son niveau. Il est evident que ces _couches_ n’ont pas ete soulevees; mais que la _mer_ s’est _abaissee_. Or c’est la le grand point cosmologique a expliquer: tous les autres, qui tiennent a la structure de certaines montagnes inintelligibles, n’appartiendront qu’a _l’histoire naturelle_, tant qu’ils ne se lieront pas avec celui-la.”
Here are two things to be considered; the interesting facts described by our author, and the inference that he would have us draw from those facts. It would appear from the facts, that the body of schistus below, and that of lime-stone above, had not undergone the same disordering operations, or by no means in the same degree. But our author has formed another conclusion; he says, that these lime-stone strata must have been formed precisely in the place and order in which they lie at present; and the reason for this is, because these strata appeared to him to follow perfectly the contour of the summit of this mountain. Now, had there been in the top of this mountain a deep hollow encompassed about with the schistus rock; and had this cavity been now found filled with horizontal strata, there might have been some shadow of reason for supposing those strata to have been deposited upon the top of the mountain. But to suppose, _first_, that shells and corals should be deposited upon the convex summit of a mountain which was then covered by the sea; _secondly_, that these moveable materials should remain upon the summit, while the sea had changed its place; and, _lastly_, that those shells and corals left by the sea upon the top of a mountain should become strata of solid limestone, and have also metallic veins in it, certainly holds of no principle of natural philosophy that I am acquainted with. If, therefore, such an appearance as this were to be employed either in illustration or confirmation of a theory, it would itself require to be explained; but this is a task that this cosmologists does not seem willing to undertake.
He has formed a hypothesis for explaining the general appearance of that which was once the bottom of the sea being now found forming the summits of our mountains; but surely this philosopher will acknowledge, that those natural appearances, in any particular place, will be the same, whether we suppose the bottom of the sea to have been raised, as in the present theory, or the surface of the sea to have sunk according to his hypothesis. For, it is equally easy to suppose a portion of the earth to have been raised all this height, as to suppose all the rest of the surface of the globe to have sunk an equal space, while a small portion of the bottom of the sea, remaining here and there fixed in its place, became the highest portion of the globe. Consequently, whatever evidence this philosopher shall find in support of his theory of the present earth, (a subject which it is not our purpose to examine) it cannot be allowed that he has here brought any argument capable of disproving the elevation of the bottom of the sea; a supposition which other theories may require.
I would now observe, in relation to the present theory, that so far as this author has reasoned justly from natural appearances, his conclusions will be found to confirm the present supposition, that there is to be perceived the distinction of primordial, and that of secondary, in the masses of this earth, without altering the general theory either with respect to the original formation of those masses, or to their posterior production.
Here one of two things must be allowed; either that those strata of schistus had been broken and distorted under a mass of other superincumbent strata; or that those superincumbent strata had been deposited upon the broken and distorted strata at the bottom of the sea. Our author, who has examined the subject, inclines to think, that this last has been the case. If, therefore, strata had been deposited upon broken and bare rocks of schistus, it is probable that these had been sunk in the sea after having been exposed to the atmosphere, and served the purpose of land upon the globe.[31]
[Note 31: This is also supported by another very interesting observation contained in this letter. M. de Luc observes, that in this country the schistus is generally covered by strata of lime-stone, and that these lime-stone strata are again covered with those of sand-stone, in which are found a great many fragments of schistus lying flat. Therefore, while those sand-stone strata were collecting at the bottom of the sea, there had been rocks of schistus in some other place, from whence those fragments bad been detached.]
An example of the same kind also occurs in the _Discours sur l’Histoire Naturelle de la Suisse_; and this author of the _Tableaux de la Suisse_ has given a very distinct description of that appearance, which is perhaps the more to be valued as a piece of natural history, as this intelligent author does not pretend to any geological theory, but simply narrates what he has seen, with such pertinent observations on the subject as naturally must occur to a thinking person on the spot.–(Discours, etc. page 228. Entree au pays de Grisons).
“Du village d’Elen on continue a monter le reste du petit vallon pendant une lieue et demie parmi les memes especes de pierres qu’on vient de decrire; en passant au travers de bois et de forets de sapins et de quelques paturages dont ce haut est couvert, on parvient au pied du Bundnerberg, montagne des grisons, qui forme la tete du vallon. On laisse a droite un fond ou espece d’entonnoir, entoure de tres-hautes montagnes inaccessibles, pour s’enfourrer a gauche entre des rochers qui font fort resserres, ou coule un torrent. Ce lieu seroit horreur si on ne se trouvoit accoutume, par degres, a voir de ces positions effrayantes: tout y est aride, il n’y a plus d’arbres ni de vegetaux ce sont des rochers entasses les un sur les autres; ce lieu paroit d’autant plus affreux que le passage a ete subit, et qu’en sortant de bois et des forets, on se trouve tout-a-coup parmi ces rochers qui s’elevent comme des murailles, et dont on ne voit pas la cime; cette gorge ou cette entree qui se nomme Jetz, est la communication du Canton du Glaris aux Gritons; on a dit precedemment qu’il y en avoit une plus aisee par le Gros-Thal ou le grand vallon. Ce passage est tres-curieux pour la Lithogeognosie, il est rare de trouver autant de phenomenes interessans rassembles, et des substances aussi variees par rapport a leurs positions; c’est le local qui merite le plus d’etre examine en Suisse, et la plus difficile que nous ayons parcouru. On se souviendra que nous avons continuellement monte depuis Glaris, et que nous nous trouvons au pied de ces montagnes ou de ces pics etonnans qui dominent les hautes Alpes; on trouve ici la facilite peu commune de pouvoir examiner, et voir le pied ou les fondemens de ces colosses qui couronnent le globe, parce qu’ils sont ordinairement entoures de leurs debris et de leurs eboulemens qui en cachent le pied. Ici c’est une roche de schiste bleuatre, dure et compact, traversee de filons de quartz blanc, et quelquefois jaunatre, dans laquelle on a taille un sentier pour pouvoir en franchir le pied. Cette roche s’eleve a une hauteur prodigieuse, est presque verticale, et ces couches sont a quatre-vingt degres d’inclinaison. L’imagination est effrayee de voir que de pareilles masses ayent pu etre ebranlees et deplacees au point d’avoir fait presque un quart de conversion. Apres avoir monte et suivi cette roche parmi les pierres et les decombres, une heure et demie, on trouve cette roche de schiste surmontee d’autres rochers fort hauts qui sont calcaires, et dont les lits sont fort horizontaux. Les schistes, qui sont directement sous les roches calcaires, conservent la meme inclinaison qu’elles ont a leur pied.”
Here is an observation which certainly agrees with that given by M. de Luc, and would seem to confirm this conclusion, that strata had been deposited upon those _schisti_ after they had been changed from their natural or horizontal position, and become vertical; at the same time, this conclusion is not of necessary consequence, without examining concomitant appearances, and finding particular marks by which this operation might be traced; for the simply finding horizontal strata, placed above vertical or much inclined schiste, is not sufficient, of itself, to constitute that fact, while it is acknowledged that every species of fracture, dislocation, and contortion, is to be found among the displaced strata of the globe.
Since writing this chapter, I am enabled to speak more decisively upon that point, having acquired more light upon the subject, as will appear in the next chapter.
CHAP. VI.
The Theory of interchanging Sea and Land illustrated by an Investigation of the Primary and Secondary Strata.
SECT. I.–A distinct View of the Primary and Secondary Strata.
Having given a view of what seems to be the primary and secondary strata, from the observations of authors, and having given what was my opinion when I first wrote that chapter, I am now to treat of this subject from observations of my own, which I made since forming that opinion.
From Portpatrick, on the west coast, to St Abb’s Head, on the east, there is a tract of schistus mountains, in which the strata are generally much inclined, or approaching to the vertical situation; and it is in these inclined strata that geologists allege that there is not to be found any vestige of organised body. This opinion, however, I have now proved to be erroneous.
There cannot be any doubt with regard to the original formation of those stratified bodies, as having been formed of the materials that are natural to this earth, viz. the detritus of former bodies; and as having been deposited in water, like the horizontal strata: For the substances and bodies of which they are visibly composed are no other than those which form the most regular horizontal strata, and which are continually traveling, or transported at the bottom of the sea, such as gravel, and sand, argillaceous and micaceous bodies.
On each side of this ridge of mountains, which towards the east end is but narrow, there is a lower country composed of strata in general more horizontal; and among which strata, besides coal, there are also found the relics of organised bodies.
Abstracting at present from any consideration of organised bodies among the materials of those strata, it may be affirmed, that the materials which form the strata in the mountains and in the low country, are similar, or of the same nature; that they have, in both places, been consolidated by the same means, viz. heat and fusion; and that the same or similar accidents have happened to them, such as change from their original position, and mineral veins traversing them in various shapes. Yet still there is a distinctive character for those two bodies, the alpine and the horizontal strata; for, while the horizontal position appears natural to the one, and the changes from that particular state to be only an accident, the vertical position appears to be more natural to the other, which is seldom found horizontal.
Therefore, altho’ it is unquestionable that the strata in the alpine and low countries had the same or a similar original, yet, as the vertical position, which is the greatest possible change in that respect, is more natural to the alpine strata, or only necessary in the natural order of those bodies, we are to consider this great disorder or change from the natural state of their original formation, as the proper character of