SECTION VI.

GEOLOGICAL PHENOMENA RESULTING FROM THE EARTH'S

PROTOROTATION.

CHAPTER XXVI.

The previous subject continued. Formation of Earths and Soils. The attendant circumstances peculiarly favourable for this needful process. The unconformable rocky masses which overlie the coal measures. Geological evidence of their existence. Enquiry into their origin, as made known to us by the Dynamical Theory. Geological character of the newer Secondary Suites. The New Red Sandstone, the Oolitic, and the Cretaceous groups. Their saliferous associates reserved for a future Section. The Supra-cretaceous deposits, as explained by this Theory, and the clear line of demarcation which it draws between them and the still more recent surface accumulations, the residium of the Deluge.

To make manifest that everything was arranged by a Wisdom which is infinite, and that all the attendant circumstances were made to conspire towards the completion of the great plan of creation, then progressively and rapidly being unfolded, we shall, at this opportune juncture, direct the attention to the nature and formation of earths and soils. In doing this, we shall merely recapitulate, in succession, those Theorems which have reference to these substances. The subjects they treat of being quite of an elementary character, we do not consider it requisite to detain the general argument by bringing forward their evidences; reference may therefore be made to their respective authorities, should any doubts be entertained, or further information required on the subject. In passing, however, we may take occasion to mention, what may perhaps not be so generally known, namely—that some celebrated French chemists have discovered, and satisfactorily

proved, that when the contained oxygen has been doubled in water, its oxydizing power is greatly augmented, the oxydation, and consequently the formation of the bases of earths, when it is in this state, going on with a rapidity almost inconceivable. Having made this advertency, we hasten to unfold the general outlines of this additional and conspicuous instance of that provident forethought and consummate wisdom which made all things work together for the accomplishment of His great designs. In the present instance, the chief object having been the formation of an appropriate bed of earthy soil, to receive and sustain that rich and magnificent vegetable covering which was so soon to be thrown over and to adorn the new formed land, composed of an attractive variety of foliage, of flowers, and of fruits, brought forth, by the word of His power, in maturity and perfection. The ninety-eighth Theorem states, "That earthy matter consists generally of some metallic substance in chemical combination with oxygen, forming an oxide. That the combination of earthy metals with oxygen usually takes place when favoured by a sufficient elevation of temperature. That this constitutes the important change which many metals undergo when heated under exposure to the air. And that, to facilitate this combination, it is necessary to raise their temperature considerably, to some metals it being even requisite to apply very intense heats.

When we reflect on the stupendous chemical process then going on, the introduction of heated continents and mountains abounding with metals and metalloids, into the midst of a universal ocean, plentifully saturated with oxygen, and on the increased powers of oxydation which water possesses when its associated oxygen is augmented, we are forced to exclaim, "This indeed was a laboratory worthy of the Creator, when producing the materials for the soils of a world!" Any observations by us on a subject such as this would be wholly superfluous. To those who can appreciate its magnificence they will be unnecessary; to those who cannot they would be of no avail! We shall, therefore, go on to exhibit the manner in which these earthy oxides are generally removed from where they are formed; and, last of all, enumerate the remaining substances which contribute to the formation of

perfect soil; and throughout the whole, there will be observed the same wise adaptation of means to the desired end.

The manner in which sands and soils are at present formed is under atmospheric influences. Although the atmosphere, and consequently, none of its meteorological changes, were in existence at the period to which we allude, yet it is presumed, that in the primitive ocean, abounding with carbonic acid and free oxygen, thrown into violent motion and agitation, there existed elements in every respect equal in effect, and superior in power, to those which are now in daily operation repairing the continual waste of soil absorbed in vegetation, and swept into the ocean by rains, rivers, &c.; consequently we may look upon the original method of formation, as that which produced the stock, constituted under strong and powerful influences, while the latter is destined merely to keep it up by atmospheric agency.

With respect to the material itself, the hundred and fourth Theorem states, "That, in order to form a just idea of soilwhich consists of small stones and sand, impalpable earthy matter, decaying animal and vegetable substances, and small quantities of salts—it is necessary to conceive different rocks to be decomposed and ground to fineness, some of their soluble parts dissolved in water, and that water adhering to the mass, and the whole mixed with the remains of vegetables and animals in different stages of decay, together with small portions of salts; the earthy matter, however, constituting their chief proportion. And that when the mineral ingredients of soils are traced to their ultimate elements, they are found to consist chiefly of silica, alumina, magnesia, and the oxides of iron and of manganese."

Bearing this information, and that which we acquired in the previous chapters in mind, and applying it to the operations going forward on the first and second days of the Mosaic week, it will be acknowledged, that every requisite element was present for the production, in the shortest possible period, of a quantity of siliceous and calcareous materials, which, when joined to the debris spread abroad by the explosion of the protruded rocks, when they burst through the superincumbent strata, would be sufficient to form, by subsequent deposition,

those unconformable suites which overlie the coal measures, the remains of the submarine vegetation of the primitive world, and also other portions of the original surface.

Therefore, in pursuance of the method hitherto observed, it is now requisite to enquire whether geologists recognise any formations, whatever be their denomination, which correspond in character to the material here supposed to have been spread abroad. If we set aside, for the present, the limitations imposed upon us by the nomenclatures of the various geological systems, and take a comprehensive view of the mineralogical and geological characteristics of these formations themselves, we shall discover, with peculiar satisfaction, in the proofs which geology affords, a striking corroboration of the views we have adopted, so much so, indeed, that the substance of the following evidence may be summed up in one brief sentence, namely, every formation superior to the carboniferous group, and those of the same era, affords evident symptoms of having been deposited from a heterogeneous mass of mineral debris, occasioned by some great and general catastrophe; while the coal series themselves, with the mountain limestone, and old red sandstone, which underlie them, exhibit as evident symptoms of having together undergone some violent movement about the same period.

To prove this, we shall undertake a new series of enquiries, commencing with what is contained in the thirty-first Theorem, which states, "That in the coal measures there is considerable persistency of character; those termed 'independent' being usually found in strata conformably to and overlying the mountain limestone and the old red sandstone; the whole three formations appearing to have been moved simultaneously, by the influence of great force, from where they were originally formed. That the magnesian limestone and new red sandstone, which usually overlie the coal measures, are, on the other hand, unconformable to them and more horizontal in their position. That the lower portion of the new red sandstone series is generally formed of conglomerate and strata. And, finally, that there is a decided difference between the coal found in the independent formations, and the lignite or brown coal of the more recent deposits."

In support of these opinions Dr. M'Culloch expresses himself thus

“The coal series which have been called independent, forms the great repository of that mineral in Britain, though not the exclusive one; and its leading character is to occupy a geological position superior to the old red sandstone, and inferior to the new one, or to the red marl. . . . . . As the beds of coal are found accompanying and alternating with stratified rocks, so they are also disposed in strata parallel to them. These strata are in every respect analogous, in their forms, dispositions, and accidents, to those of the rocks with which they occur. In position, they are horizontal, or inclined at various angles, often highly elevated, as is the whole series. . . . The thickness of a coal stratum varies, even from less than an inch, to ten or twelve feet, but it rarely exceeds two or three, and is, more often, much less; and thus particular strata become extenuated till they disappear.

"Now, it is essential to remark, that the old red sandstone, the mountain limestone, and the coal series, are all disturbed, being elevated, undulated, and fractured in various ways. . .... And it must, similarly, be recollected, that a new order commences with the magnesian limestone, and the red marl; or that they are placed on the coal series, and the inferior strata, in an unconformable position, while the lower substance also presents that conglomerate structure, which everywhere throughout nature accompanies a new order in rocks. Hence the first three deposits have often been united, as forming one class, and as if they had undergone but one disturbance common to the whole. But from the former remarks on this subject, it is plain that the coal series is really distinct, in time and production, from the inferior strata; and hence cannot be always truly conformable to them, though the last general disturbance is common to the whole."*

"It was not enough," observes Professor Buckland, when treating of the carboniferous series, "that these vegetable remains should have been transported from their native forests, and buried at the bottom of ancient lakes and estuaries and seas, and there converted into coal; it was further necessary that great and extensive changes of level should elevate, and convert into dry and habitable land, strata loaded with riches, that would for ever have remained useless,

*Geology, vol. ii. pp. 299-304.