. The pictorial sketch-book of Pennsylvania, or, Its scenery, internal improvements, resources, and agriculture, populary described . glomerate detritrisborne into the estuaries of lakes and rivers—after which the watersprobably receded, and suffered another supply of vegetable matter toaccumulate. That something like this process is at least probable, issufficiently evident from the alternation of marine deposits and othermatter with the coal beds, and their position high up upon the sum-mits of mountains, hundreds of miles from the present flow of thesea. How else could they have been deposi
. The pictorial sketch-book of Pennsylvania, or, Its scenery, internal improvements, resources, and agriculture, populary described . glomerate detritrisborne into the estuaries of lakes and rivers—after which the watersprobably receded, and suffered another supply of vegetable matter toaccumulate. That something like this process is at least probable, issufficiently evident from the alternation of marine deposits and othermatter with the coal beds, and their position high up upon the sum-mits of mountains, hundreds of miles from the present flow of thesea. How else could they have been deposited there, in regularorder and succession?—though It is nevertheless probable that extra-ordinary floods, internal convulsions and outbreaks in the earthscrust, as well as the general changes of land into sea, and sea into ANTHRACITE COAL FORMATION. 133 land, at that period, (and even now constantly going on,) contributedmuch as co-operative agents. We append a single figure, 18, showingthe horizontal position of strata, which will also serve to illustrate thealternation of coal veins with other deposits in the same FIGURE 18. The vegetable material, therefore, having been thus secured, achemical process subsequently ensued, as before stated, by which themass was turned into coal. The fermentation produced by the pres-sure of the overlaying strata, and the impossibility of the immediateescape of its gaseous elements, heated it sufficiently to produce a bodyof pitchy or bituminous matter, and the coal is consequently bitumi-nous, or only partially so, in proportion as these gases were subse-quently let out by the cracks, and fissures, and disruptions, going onin the surrounding strata. For we find that when the strata areundisturbed, bituminous or fat coals predominate ; whereas, wherethe strata are inverted, and torn and disruptured, anthracite, or coalswhich have lost the greater portion of this pitchy matter, , after long-continued and constantly incr
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Keywords: ., bookcentury1800, bookdecade, booksubjectminesandmineralresources
