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The False Theories of Geologists respecting the Sources of the Materials of which the Strata were formed.
But geologists are not only forbidden by the laws of matter from assuming the existence of such granitic continents, islands, and mountains a8 they suppose, anterior to the formation of the strata, but they are without any certainty that there were any mountains, islands, or continents whatever, that could have furnished materials in any considerable measure for such vast deposits. This is admitted by Professor Phillips.
"Whether at the time when all our continents were beneath the sea, there were other continents raised above it, is a matter which it is difficult to bring fairly within the scope of inductive science, except in a very limited form, and upon rather doubtful assumptions. The only clear and certain evidence of the existence of the land in other situations than where it now appears, is to be sought in the history of terrestrial organic exuviae imbedded in the earth; the only reasonable presumptive evidence in favor of such a doctrine must be founded on mechanical considerations connected with the mass and depth of the waters of the ocean. To conclude that because continents were raised in one quarter, others must have been depressed elsewhere in a certain proportion, is inadmissible, because it requires us to admit what is perhaps false, viz. that the spaces occupied by the solid and liquid parts of the mass of the globe have always been exactly and invariably in the same proportion to each other as at present. Who can assure us of the truth, or even the probability of such a law V—Guide to Geology, p. 38.
Such is undoubtedly the fact. The only certain evidence which the strata themselves can furnish of the existence of dry land at the period of their formation, is the presence in them of fossilized animals and vegetables, to the existence of which dry land was necessary. The mere fact that the strata were formed beneath the waters of the ocean is no proof that the materials of which they consist were derived from continents and mountains, any more than it is that they were not. Nor is the fact that a portion of their materials were probably or certainly drawn from such a source, any proof that they all were, any more than the fact that some of the waters of the ocean have run from mountains and continents is a proof that they all originally descended from those sources.
Mr. Lyell makes the same admission.
"If asked where the continent was placed, from the ruins of which the Wealden strata were derived, we might be almost tempted to speculate on the former existence of the Atlantis of Plato as true in geology, although fabulous as an historical event. We know that the present European lands have come into existence almost entirely since the deposition of the chalk; and the same period may have sufficed for the disappearance of a continent of equal magnitude situated farther west."—LyeWs Principles, vol. ii., p. 458.
Mr. Macculloch held that the mountains and continents from which the materials of the strata were originally derived, preceded those that directly furnished the elements of the present series.
"That this system had a beginning we are certain ; where that may be, we know not; but for us it is placed beyond that era at which we can no longer trace the marks of a change of order of the destruction and renovation of its form. It is from this point that a theory of the earth must at present commence.
"Hence, then, I have drawn the conclusion that there was one terraqueous globe, one earth divided into sea and land, even prior to that last named; containing mountains to furnish and an ocean to receive those materials which formed the second set of mountains, whose fragments are now imbedded in our primary strata, or in those of a third order. Geologists may perhaps be startled at conclusions which they have hitherto overlooked, obvious as they are, and clear as the reasoning is: how they should not have been seen by those who have shown such anxiety to maintain the antiquity of the globe, it is not for me to explain."—Geology, vol. i., pp.462, 464-466.
Yet notwithstanding this fancied proof of the existence of at least two sets of mountains and continents that were the sources, in succession, of the materials of "our primary strata," he yet acknowledges himself unable to decide whether or not those first mountains were, in a measure at least, identical with those that now exist on the globe.
"In this state of the earth the present primary strata occupied horizontal positions beneath this ocean; though we are uncertain whether certain parts of those which we now esteem such might not have been the very mountains whence they were formed. This is probably the fact, however incapable we yet are of proving it, owing to our imperfect observations, and the still more imperfect views which geologists have hitherto taken of a theory of the earth. We cannot conceive that all the supra-marine land which produced the primary strata should have been mouldered and transferred to the sea before these underwent their first disturbance; nor that it should have all been depressed beneath the sea while the new-formed rocks were elevated."—Vol. i., p. 468.
This extraordinary induction scarcely merits a formal confutation. A more dim and uncertain argument could hardly be made the ground of the vast train of consequences he deduces from it. The point on which he builds his inference is altogether assumed by him, inasmuch as the existence in the strata of the fragments of other rocks, is not of itself a proof that those fragments were derived from mountains, unless it is first established that the materials of such rocks cannot have been drawn from any other source; which is the precise point he was to demonstrate. This whole imagined induction, indeed from the processes that are now taking place, is, as we shall hereafter show, a fallacy; inasmuch as the fact that minute particles and sands are borne down to the sea from the present mountains and plains, which consist in a large degree of loose soils, or sedimentary rocks that are easily disintegrated, is no evidence that similar materials and on much the same scale would have been carried down from mountains and plains that consisted exclusively of granite. The supposition is a solecism, as it implies that the same causes, though acting on different materials and in different conditions, would nevertheless produce precisely the same effects.