Читать книгу The Evacuation of England: The Twist in the Gulf Stream онлайн

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“In the West Indies and on the Isthmus of Panama we have the states of instability which we have signalized, viz., secondary deposits of a somewhat loose and unconsolidated material, and wanting in the deeply bedded crystalline rocks which in New England, in the Adirondacks, and the Piedmont or higher regions abutting on the coastal plain in the northern United States, furnish a solid, and probably fundamentally deep seated pediment of resistance to shock. Again in the West Indies and in the Isthmus, we have the beds unconformable over each other, which you will recall in our symbol of the brick wall, was a feature of weakness; also these unconformable beds are inclined in anti-clinals, a further aspect of structural insolvency; and further these beds have been widely, pervasively, in places, infiltrated and ruptured by subsequent introductions of volcanic substance, ashes, lavas and intrusive magmas. Thus the geological aggregates present the previously illustrated condition of fragility, and the absence of the so-called tectonic elements of rigidity. But still one step more in our disheartening study of this equatorial problem.