Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: May 26, 2025
It is clear that the lava once filled the whole valley up to the dotted line d-a; but the river has gradually swept away all below that line, while the tributary torrent has laid open a transverse section; by which we perceive, in the first place, that the lava is composed, as usual in this country, of three parts: the uppermost, at a, being scoriaceous, the second b, presenting irregular prisms; and the third, c, with regular columns, which are vertical on the banks of the Volant, where they rest on a horizontal base of gneiss, but which are inclined at an angle of 45 degrees, at g, and are nearly horizontal at f, their position having been everywhere determined, according to the law before mentioned, by the form of the original valley.
Whereas in the region A-B, where the growth of the forest has never been interrupted by submergence, there will simply be one seam, two yards thick, corresponding to the united thickness of the beds B-E and B-C. It may be objected that the uninterrupted growth of plants during the interval of time required for the filling up of the lagoon will have caused the vegetable matter in the region D-A-B to be thicker than the two distinct seams E and C, and no doubt there would actually be a slight excess representing one or more generation of trees and plants forming the undergrowth; but this excess of vegetable matter, when compressed into coal, would be so insignificant in thickness that the miner might still affirm that the seam D-A throughout the area D-A-B was equal to the two seams C and E.
Word Of The Day
Others Looking