CHAPTER V.

General Nature of the Formations on the Earth.-Origin and Progress of Secondary Formations.-Causes of Stratification in Secondary Rocks.—Such Deposits become gradually Mineralized.-Calcareous Formations.-Salt Deposits.-Proof of Granite not being an Aqueous Deposit.-Secondary Formations now in Progress in the Bed of the Ocean.

The active researches of geologists into the existing phenomena on the surface of the earth, have led to the following conclusions with respect to mineral bodies.

"PRIMITIVE ROCKS

"Consist only of crystalline formations;

They contain no organic remains ;

They are found below all other rocks;

And they rise from the base, through all other rocks, forming the summits of the most lofty mountains.

"TRANSITION AND FLOETZ, (or Secondary Rocks,) "Consist partly of crystalline, partly of mechanical deposits; They contain organic remains of sea shells;

And are never found under primitive rocks.

"ALLUVIAL DEPOSITS

"Consist of mechanical deposits;

They result from the ruin of rocks;

They contain abundance of shells, together with the bones of

quadrupeds," and of the human race;

"And they are found above all the other rocks."*

* Phillips's Geology.

G

But in

Thus far the chaotic and the Mosaic geologies coincide; the facts are self-evident, and within the reach of every one who will take the trouble to examine them. But when the causes by which these facts have been produced, come under consideration, the two geologies separate; the one following the path which history has marked out, and which reason can comprehend, leading at every step towards the light of truth; the other, under a variety of leaders, plunges into the dark and devious mazes of hypothesis, rejects the guidance of history, and is led more and more into obscurity and error. There is no possible way of clearing this labyrinth and of gaining the desired end, but by retracing our steps and taking advantage of the clue which history affords us. doing this, we must keep constantly in mind the difficulties from which we have escaped; and the impossibility we have experienced of tracing primitive effects to secondary causes. Truth and reason acknowledge but one primitive cause; and that is, an Almighty, though to us, incomprehensible CREATOR. Having found the arguments in favour of secondary causes, or the mere laws of nature, as they are called, totally insufficient to account satisfactorily to our reason, for the first formation of crystallized mineral bodies, any more than for the first formation of animal or vegetable bodies, we come to the unavoidable conclusion that they were all the creative work of an Almighty hand. But as it is evident that this creation, as soon as completed, was submitted to certain laws, by some of which a constant succession of decay and re-formation was to be kept up in the mineral world, at least as far as regards the mere surface of the earth, it may be considered quite within the scope of our reason to examine these laws, and to account for these secondary effects by secondary

causes.

We find, then, that it is one constant law of the Creator that the action of the atmosphere shall decompose or break up the mineral bodies exposed to its influence. We find another called the law of gravity, by which the waters of the earth, in seeking their own level, are hurried from the highest mountains to the sea; carrying along with them abundance of mineral matter in the shape of sand, mud and gravel. We find a third law by which the waters of the ocean are kept in constant agitation; and the mineral matter imported by the rivers, is arranged in classes, according to the weight and volume of its parts, and distributed over the sea bed in va

rious directions, and in various quantities, according to the nature of the currents which remove it.*

These three laws, which have been in constant action since the first creation of the seas, the rivers, and the atmosphere, which events, history informs us, took place about 6000 years ago, are fully sufficient to account for a prodigious accumulation of decomposed mineral matter in the bed of the ocean.t

* This law of arrangement, which is founded on the law of gravity, may be looked upon as the great agent in distinct stratification. And as this law could not be in force without the lateral movement kept up by the currents of the ocean, we cannot look for its effects in situations where such constant action and re-action of currents do not exist. Thus we never can expect to find the secondary formations of fresh water lakes, however extensive, in the same stratified arrangement as in the bed of the sea. Whatever sand, mud, gravel or rock is lodged in a lake by rivers, must, therefore, remain exactly in the same irregular mass as when first imported and deposited; and, accordingly, we never find the shores of lakes, or the banks of rivers, presenting the same distinct classification as is always found, more or less, on the sea shores. For the same reason, we may be assured that in draining marshes or lakes, when we cut through distinct strata of sand, marl, gravel, or fine clay, which are all generally found in strata in such situations, we are to attribute such deposits, as well as their fossil contents, to a period when the action of the sea was in force; and that the hollow basin-like form which now causes a marsh or a lake, must have been at least partially coated with marine strata at the period of the deluge. We must, however, be guided by circumstances, in forming a judgment in such cases, as there can be no doubt that many places which were formerly shallow lakes or marshes, are now nearly dry, from the growth of peat, or the accumulation of the debris of land streams; and we must, consequently, judge of the nature of the soils, and of the period of the fossil deposits, according to their degree of stratification, and the nature of the embedding soils.

The remains of deer and other animals often found in peat mosses, must, therefore, be considered antediluvian, or, otherwise, according to the situation in which they oecur, and according to the presence or absence of land streams, by the agency of which the deposits might have been made. The well known fossil elks of Ireland, and of the Isle of Man, may probably be regarded as truly antediluvian; though geologists have often considered them as much more modern.

+ In a late publication by Mr. Lyell, which has come under my notice since the above was written, and which is a work full of information of the most important kind, with regard to natural secondary causes, which he considers sufficient to account for all the appearances on the surface of the earth, we find a calculation with respect to the quantity of mud lodged in the sea by the Ganges, which appears, as it is well calculated to do, to shake to its founda

Should any event, then, take place to enable us to examine that bed in a dry state, we could feel no surprise if we should discover the original crystallized surface of the earth, loaded with various accumulations, resulting evidently from such decomposition of rocks as the atmosphere every where occasions, as the rivers every where become charged with, and as the currents of the ocean must, at all times, be depositing. As it is one part of the laws of gravity, that deposits in fluids shall fall to the bottom, in the same horizontal position in which these fluids themselves are retained by attraction, we should expect to find these deposits in this particular position; unless the irregular form of that part of the primitive earth on which they happened to be laid, occasioned an irregularity also in the deposited mass. Should any very considerable elevation or irregularity have existed on the primitive surface of the earth, such as we now denominate an Al

tion the theory of the author; for it is obvious, that it proves too much to suit his idea of millions of years, as the age of the world. After stating the calculations of Rennell, and of Major Colebrooke, with respect to the waters of the Ganges, which are calculated to contain one part, in four, of mud, Mr. Lyell continues: "But, although we can readily believe the proportion of sediment in the waters of the Ganges to exceed that of any river in northern latitudes, we are somewhat staggered by the results to which we must arrive, if we compare the proportion of mud, as given by Rennell, with his computation of the quantity of water discharged, which latter is probably very correct. If it be true that the Ganges, in the flood-season, contains one part, in four, of mud, we shall then be obliged to suppose that there passes down, every four days, a quantity of mud, equal in volume to the water which is discharged in the course of twenty-four hours. If the mud be assumed to be equal to one half the specific gravity of granite, (it would, however, be more,) the weight of matter daily carried down in the flood season, would be about equal to 74 times the weight of the Great Pyramid of Egypt. Even if it could be proved that the turbid waters of the Ganges contain one part in a hundred of mud, which is possible, and which is affirmed to be the case in regard to the Rhine, we should be brought to the extraordinary conclusion, that there passes down, every day, into the Bay of Bengal, a mass more than equal in weight and bulk to the Great Pyramid."-Principles of Geology, vol. i. page 284.

Let the candour of this very able author calculate this effect over the whole earth for 2000 years, and then consider it as having acted for one or two millions of years; and let him say which result bears the most just proportion to the secondary formations actually found to load the primitive surface of the earth.

pine height, but at the bottom of the primitive sea, we should expect to discover the various horizontal deposits of various changing currents laid one above another, towards its top. If this top had been of sufficient elevation to be above the surface of the waters in the form of an island, we should not look for any such deposits above the level which the waters had reached; but, on the contrary, we should expect to find the bare primitive rock free from all secondary formation.*

After taking this general view of the bed of a former ocean, supposing it to be within our power to do so, we should naturally enter upon a more minute examination of the various mineral masses of which these deposits were formed.t And here we should soon find that the laws by which the world is governed, are not confined to those three, by the action of which these deposits have been formed. We should have to consult the voluminous code of chemical laws, the foundations of which, like those of all the other laws of God, are beyond our comprehension; but in the action of which, human science has made so many brilliant discoveries. We should every where discover effects produced by these chemical laws, varying according to the situation, and the nature of the materials to be acted upon. Instead of finding these materials, when freed from the waters in which they had been

*Of the nature of the bed of the ocean we know but little. The portions of it which have been explored by soundings, are found, in one place, to contain immense collections of the wreck of testaceous animals, intermixed with sand or gravel; and in another, to consist of soft alluvial mud, several feet in depth. Donati found the bottom of the Adriatic to be composed of a compact bed of shells, not less than a hundred feet in thickness."-Edin. Encyclop. Physical Geography, p. 518.

It was likewise discovered, in the researches of Donati, that, at a very few feet below the surface of the bed of the Adriatic, the deposits were converted, by pressure, and by the actions of the chemical laws of nature, into solid marble, and the shells completely petrified.

+"Various marine substances are to be found almost in every part of the extensive province of Chili, and even on the tops of some of its lofty mountains. In the main ridge of the Andes, the internal structure consists of primitive rocks of granite and quartz. The maritime and midland mountains, together with the lateral chains of the Andes, are of secondary formation; their strata, which are horizontal, and of unequal thickness, abound with marine productions, and contain the impressions of animal bodies."-Molina's Natural and Civil History of Chili.