Page:The Geologist, volume 5.djvu/22

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8
THE GEOLOGIST.

areas in Shropshire and Staffordshire it is one great red arenaceous series, with a few subordinate courses of calcareous conglomerate, Following it to the north, Mr. Binney has demonstrated that the fossils of the Zechstein show themselves in the heart of red marls which occupy on the whole a superior part of such a red series; and in tracing these rocks northwards he has demonstrated that there are, besides, two great underlying masses, first of conglomerates and breccias, and next of soft red sandstones, the latter attaining, as he believes, a thickness of not less than 2000 feet. Here then the Permian may be considered a Trias. Professor Harkness, in a memoir he is preparing, estimates the thickness of these Lower Sandstones and conglomerates to the N.E. of West Ormside, in Cumberland, at 4000 to 5000 feet, and shows that they are surmounted by marl-slates bearing plants, thin-bedded red sandstone, grey shale, and sandstone and limestone, the latter—the representative of the Magnesian Limestone—being covered by red argillaceous shale.[1] Now in all these cases the Permian is a series divisible into three or more parts. But when we follow the same group into Scotland, it there parts with its calcareous feature, and, becomng one red sandstone of vast thickness, is again a Monas.

I have entered into this explanation because my friend Dr. Geinitz has seized upon one illustration in my work 'Siluria' which shows that in certain tracts, where the Zechstein or Magnesian Limestone is subordinate to an enveloping series of sandstones, the Permian of my classification is there as much a tripartite Palæozoic group as the Trias of Central Grermany is a triple formation of Mesozoic age. Unless, therefore, the data to which my associates and self have appealed, in the work on 'Russia and the Ural Mountains,' and which I have further developed in Memoirs read before the Geological Society, and in my two editions of 'Siluria,' be shown to be inaccurate, I hold to the opinion that there are tracts in which the Zechstein is simply a fossiliferous zone in a great sandstone series, to which no division by numerals can be logically applied. Even if I do not appeal to the natural evidences in England, Russia, and parts of Germany, but refer to those tracts where the Zechstein or Magnesian Limestone has no natural red cover, I may well ask, does not the word "Permian," in the sense in which it was originally adopted, serve for every tract wherein the uppermost palæozoic fossil animals and plants are found, whether the strata of which the group is composed form, as in Russia and Silesia, one great series of alternations of plant-bearing sandstones and marls in parts containing bands of fossiliferous limestone, or whether, as in other tracts, the Zechstein stands alone (as near Saalfeld), or in others, again, where the group is tripartite, and even quadripartite? Quite

  1. The red clay or argillaceous shale which covers the limestone is surmounted at Hilton, in Cumberland, by five hundred feet of red sandstone, which, though perfectly conformable to the subjacent Permian rocks, he considers to belong to the Bunter Sandstein of the Trias. Here, then, as in Grermany, the limestone may have a red cover, and yet the Bunter Sandstein be intact.