But the Fact Number One, which I have chosen as the subject of this chapter, is the now well established principle that any kind of fossil whatever, even "young" Tertiary rocks, may rest upon the Archaean or Azoic series, or may themselves be almost wholly metamorphosed or crystalline, thus resembling in position and outward appearance the so-called "oldest" rocks.
The first part of this proposition, about any rocks occurring next to the Archaean, is covered by the following quotation from Dana:[15]
"A stratum of one era may rest upon any stratum in the whole of the series below it,—the Coal-measures on either the Archaean, Silurian, or Devonian strata; and the Jurassic, Cretaceous, or Tertiary on any one of the earlier rocks, the intermediate being wanting. The Quaternary in America in some cases rests on Archaean rocks, in others on Silurian or Devonian, in others on Cretaceous or Tertiary."
It would be tedious to multiply testimony on a point so universally understood.
As for the other half of this fact, that even the so-called "youngest" rocks may be metamorphic and crystalline just as well as the "oldest," it also is now a recognized commonplace of science. Dana[16] says that as early as 1833 Lyell taught this as a general truth applicable to "all the formations from the earliest to the latest."
The first reference I can find to any disproof of this old fable of Werner's, that only certain kinds of rock are to be found next to the "Primitive" or Archaean, is in the observations of Studer and Beaumont in the Alps, (1826-28), 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."
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."[17]
Hence we need not be surprised at the following statement of the situation by Zittel.[18]