United States or Jordan ? Vote for the TOP Country of the Week !
Some few only were based on clay and shale; none of them, except Calamites, on sandstone. The erect trees, therefore, appeared in general to have grown on beds of vegetable matter. In the underclays Stigmaria abounds.
In some places, almost all the plants were calamites, in others ferns. Between the years 1837 and 1840, six fossil trees were discovered in the coal- fields of Lancashire, where it is intersected by the Bolton railway. They were all at right angles to the plane of the bed, which dips about 15 degrees to the south.
Sir R. Murchison groups with this upper division of the Old Red of Scotland certain light-red and yellow sandstones and grits which occur in the northernmost part of the mainland, and extend also into the Orkney and Shetland Islands. They contain Calamites and other plants which agree generically with Carboniferous forms.
They were invariably flattened to the thickness of one or two inches, and converted into coal. Their roots formed part of a stratum of coal ten inches thick, which rested on a layer of clay two inches thick, below which was a second forest resting on a two-foot seam of coal. Five feet below this, again, was a third forest with large stumps of Lepidodendra, Calamites, and other trees.
They are rich also in arsenic, brimstone, and vitriol, and contain, in no inconsiderable quantities, quicksilver, antimony, calamites, bismuth, and manganese. Even precious stones are not wanting; garnets, topazes, tourmalines, amethysts, beryls, jaspers, and chalcedonies having been found.
It contains a remarkable seam of coal, known as Russokohle or soot-coal, running at times 25 feet thick. It was separated by Geinitz and others into four zones, according to their vegetable contents, viz.: Zone of Ferns. Zone of Annularia and Calamites. Zone of Sigillaria.
There would probably never be found another unbroken period of a duration equal to that of the coal measures. Further, the roots, seeds, and the whole reproductive structure of the coal-measure plants are all present in an unequalled state of preservation. With reference to calamites, Prof.
Now we know that there were plenty of ferns and of large Calamites growing thickly together in the coal-forests, for we find their remains everywhere in the clay, so we can easily picture to ourselves how the dense jungle formed by these plants would fringe the coal-swamp, as the present plants do the Great Dismal Swamp, and would keep out all earthy matter, so that year after year the plants would die and form a thick bed of peat, afterwards to become coal.
The climate of the period, in the northern temperate zone, was of such a character that the true conifers show rings of growth, not larger, nor much less distinct, than those of many of their modern congeners. The Sigillariae and Calamites were not, as often supposed, composed wholly, or even principally, of lax and soft tissues, or necessarily short-lived.
To the north of the Boyd, there is a steep mountain barrier, striking from east to west. All these ranges are composed of sandstone, with their horizontal strata, some of which have a very fine grain. Impressions of Calamites were observed in one of the gullies. We also saw two kangaroos.
Word Of The Day