EVOLUTION AND GEOLOGY by Geo. McCready Price

Pacific Press Publishing Company · Mountain View, California · Mar 8, 1905

FromSigns of the Times, Vol. 31, No. 10.

EVOLUTION AND GEOLOGY

By Geo. McCready Price

BY GEO. MCCREADY PRICE

XIV. THE SUCCESSIVE AGES.

(Continued.)

It was a very old idea that only certain kinds of rocks were to be found next to the "Primitive," or Archaean. It is hard to find out who originated it, whether Lehmann, Füchsel, or Arduino; but the well known A. G. Werner (1749-1817), of Neptunian fame, was the first to bring it into prominence. With him this became the notorious "onion-coat" hypothesis, tho his distinctions were based entirely on mechanical and mineralogical grounds. William Smith, in England, and Brougnart and Cuvier, in France, seem to have adopted somewhat the same idea; but with them the fossils were the important things, and mineralogical character quite secondary.

For some time there seems to have been a sort of blending of the two systems, but it was not long before the fossils became the one and only test of age. This early work of William Smith, and of Brougnart and Cuvier, was limited to small sections of the great succession of life, but from the very beginning they evidently had the instinct that this succession ought to correspond to the classification series of to-day; and so, by dovetailing here and there, all the other fossils of the world have been found a place in this great hypothetical ladder of life; tho, as we shall see, in making the rocks always occur in this order, they have

Had to Invent Various Devices

quite as fanciful as the well-known "epicycles" of the Ptolemaic astronomers, and invented for a precisely similar reason, viz., because the facts would not otherwise conform to their precious theory.

But it is now a well-established fact that any kind of fossils whatever, even "young-Tertiary" rocks, may rest upon the Archaean or Azoic series, or may themselves be almost wholly metamorphosed, or crystalline.

As Dana expresses it:

The idea that gneiss and mica schist are always "Primary," or Archaean rocks; that grade of crystallisation is a safe mark of relative age; was shown to be false by Lyell ("Principles," 1830-33), who, with De la Beche (1834), rejected all Wernerian errors. Lyell went so far as to hold—as a table in the third volume of his "Principles" (1833, p. 387) shows—that crystalline or metamorphic schists may occur in all the formations from the earliest to the latest.—"Manual," p. 408.

The earliest reference I can find to any disproof of this old fable of Werner's is in the observations of Studer and Beaumont in the Alps, 1826-1828, who found "relatively young" fossils in crystalline schists, which, as Zittel says, "was

A Very Great Blow

to the geologists who upheld the hypothesis of the Archaean or pre-Cambrian age of all gneisses and schists."—"History of Geology and Paleontology," etc., p. 353, London, 1901.

It may also be mentioned here that these same observers noticed cases where "gneiss and micaceous schists repose upon unaltered sedimentary strata" (Ib.), which ought surely to have been as great a blow to Hutton's long-popular theory that such rocks were produced by heat from beneath, or from the earth's interior.

James Geikie, doubtless referring to the same series of rocks, tells us that:

In the central Alps of Switzerland, some of the Eocene strata are so highly metamorphosed that they closely resemble some of the most ancient deposits of the globe, consisting, as they do, of crystalline rocks, marble, quartz-rock, mica-schist, and gneiss."—"Manual of Hist. Geol.," p. 74.

An Unsettling Discovery.

Hence we need not be surprised at the following confession made by one of the greatest living geologists:

The last fifteen years of the nineteenth century witnessed very great advances in our knowledge of rock-deformation and metamorphism. It has been found that there is no geological epoch whose sedimentary deposits have been wholly safeguarded from metamorphic changes, and, as this broad fact has come to be realized, it has proved most unsettling, and has necessitated a revision of the stratigraphy of many districts in the light of the new possibilities. The newer researches scarcely recognize any theory; they are directed rather to the empirical method of obtaining all possible information regarding microscopic and field evidences of the passage from metamorphic to igneous rocks, and from metamorphic to sedimentary rocks."—Zittel, "Hist. of Geol.," etc., p. 360.

An Unanswerable Question.

In addition to what Zittel means by recognizing "no theory" as to the origin of species of the so-called "igneous" rocks, it seems to me that this "broad fact" ought surely to prove "most unsettling" to the traditional theories about certain fossils being intrinsically older than others. With our minds divested of all prejudice, and "this broad fact" well comprehended, where on this earth shall we look for the place to start our life-succession? That is, where in this wide world would we now go to find those kinds of fossils which we could prove, by independent arguments, to be absolutely older than all others? It may seem to be very difficult for some to discard a theory so long an integral part of all Geology; but until they can prove that this "broad fact" of Zittel's is no fact at all, I see no escape from the acknowledgment that the doctrine of any particular fossils being essentially older than others is a pure invention, with absolutely nothing to support it in nature.

Reasoning in a Circle.

For those acquainted with the ordinary methods of determining the "age" of rocks, no words of mine are needed to show how completely everything else is subordinated to this hypothesis of a definite succession in time. There was at one time in Geology an "old red sandstone," and a "new red sandstone," and whenever a red sandstone was found it was classed with the one or the other. But no one now regards color as of any particular help in classifying rocks. Thus James Geikie says:

The names applied to the various members of the fossiliferous strata had originally, in many cases, a local significance, but such names having once become current, were necessarily applied subsequently to rocks which, altho of the same age, yet frequently differed very much from those first described. Thus, when a geologist speaks of "greensand" beds, he simply means certain strata that belong to the cretaceous formation, which may or may not consist of green sand. In short, such terms are mere names and not descriptions.—"Historical Geol.," p. 31.

The same may be said of texture and mineral composition. Dana says they are to be used "always with distrust," and are "usually to be disregarded" ("Manual," p. 400). Thus, what was once called "old red sandstone," and now called Devonian, is about as often limestone or shale as sandstone; while the "chalk," or cretaceous, in scores of cases contains no chalk at all. In fact, we all know that the geological names of groups or systems of rocks mean only rocks containing certain kinds of fossils.

Another "broad fact" that ought also to prove "most unsettling" to this fetish of a life-succession, is that any formation whatever may rest conformably upon any other "older" formation. The lower may be Devonian, Silurian, or Cambrian, and the upper cretaceous or tertiary, and thus millions on millions of years have elapsed after the first and before the following beds were laid down, but the conformability is perfect, and the beds have all the appearance of having followed in quick succession. Sometimes, too, tho less frequently, these age-separated formations are lithologically the same, and can only be separated by their fossils. The literature teems with illustrations of these facts, tho

Two Examples

must here suffice, both from the Canadian Northwest.

The first will be from the summary report of R. G. McConnel, on the region about Banff, in Alberta, near the line of the Canadian Pacific Railway, and just east of the Rockies:

East of the main divide the lower carboniferous is overlaid in places by beds of lower cretaceous age, and here again, altho the two formations differ so widely in respect to age, one overlies the other without any perceptible break, and the separation of one from the other is rendered more difficult by the fact that the upper beds of the carboniferous are lithologically almost precisely like those of the cretaceous [above them]. Were it not for fossil evidence one would naturally suppose that a single formation was being dealt with.—"Annual Report," New Series, Vol. II, Part A, p. 8.

Surely this is a fearful example of the power of tradition to blind the minds of investigators to the meaning of the very plainest facts.

The other example is from the District of Athabasca:

The Devonian limestone is apparently succeeded conformably by the cretaceous, and, with the possible exception of a thin bed of conglomerate of limited extent, which occurs below Crooked Rapid, on the Athabasca, the age of which is doubtful, the vast interval of time which separated the two formations, is, so far as observed, unprecedented, either by deposition or erosion. This can hardly be explained, except on the assumption that the formation, during all this period, was buried far from land in the depths of some abyssal ocean, as the only other alternative, viz., that its surface represents a former base level of erosion [i. e., that other beds had once existed here, but had been washed away] is, in view of the remarkable persistency of the upper beds [of the lower formation], almost incredible.—"Annual Report," New Series, Vol. V, Part D, p. 52.

Some of us remember being told—at least, before the days of the "Challenger" expedition—that the "depths of some abyssal ocean" was just the place where all kinds of sediment accumulated. But how could these beds go on their wonderful journey down to these "depths" and up again, without the slightest change from the horizontal? Surely this, too, is "scarcely credible."

Regarding "the only other alternative," this author gives us on the previous page (p. 51) some idea of this "remarkable persistence of the upper beds" of the Devonian:

From the Athabasca, the Devonian limestone extends in a broad band around the southern end of Birch Mountains, and across Lake Claire, to Peace River, and up the latter stream to a point two miles above Vermillion Falls.

The distance, I should judge from the map, to be not less than 150 miles, and yet he tells us that this series of limestone "is very uniform in character throughout the district," with, I suppose, the cretaceous beds above them over all this area. But this is not all, for from Part E, Report (p. 209), of the same volume, we are told of strata near Lake Manitoba, over 500 miles away, in almost the same wonderful position—“Devonian rocks very similar in character” to those in Athabasca overlaid directly by the cretaceous, tho in this case they say “unconformably.”

The two remarkable facts brought out in this article are alone sufficient to expose the mythical character of this life-succession idea.

I shall repeat them here ere closing:

1. The “broad fact,” as stated by Zittel, that any kind of rocks whatever, i. e., containing any kinds of fossils, may rest on the Archaean, and may themselves be metamorphosed and crystalline.

2. That any kind of beds may rest in such perfect conformability on any other so-called “older” beds, over vast stretches of country, that, “were it not for fossil evidence, one would naturally suppose that a single formation was being dealt with,” while “the vast interval of time” intervening is “unrepresented either by deposition or erosion.”

(Continued next week.)

EVOLUTION AND GEOLOGY BY GEO. MCCREADY PRICE