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THE WONDERS OF GEOLOGY. Iect. Vlf. 



have sprung up, and arrived at maturity : and again another 

 subsidence, followed by an accumulation of drift. And these 

 periodical oscillations in the relative level of the land and 

 water, and successive reproductions of vegetable soil and of 

 forests, must have gone on uninterruptedly through a long 

 period of time: not in one district or country only, but in 

 various parts of the world, during the same geological epoch. 



8. The Great Dismal Swamp of Virginia. — The 

 formation of the coal-measures from terrestrial trees and 

 plants, not drifted, but growing on the areas now occupied 

 by the coal — a theory so generally adopted, that on a late 

 discussion on the subject before the Geological Society of 

 London, but one individual expressed dissent — is strongly 

 advocated by Mr. Lyell : and the following observations of 

 this profound geologist, on the " Great Dismal S?vamp" of 

 Virginia, in North Carolina, afford an interesting illustration 

 of this hypothesis. 



" The ' Great Dismal,' is a morass forty miles long, and twenty-five 

 miles in its greatest width, and has the appearance of a broad inundated 

 river plain, covered with all kinds of aquatic trees and shrubs, the soil 

 being as black as in a peat-bog. It is one enormous quagmire, soft 

 and muddy, except where the surface is rendered partially firm by a 

 covering of vegetables and their matted roots ; and is actually higher 

 than nearly all the firm and dry land which encompasses it ; and to 

 make the anomaly complete, in spite of its semi-fluid character, it is 

 higher in the interior than towards the margin. The soil of the swamp 

 is formed of vegetable matter, usually without any admixture of earthy 

 particles. We have here, in fact, a deposit of peat from ten to fifteen 

 feet in thickness, in a latitude where, owing to the heat of the sun and 

 length of the summer, no peat mosses like those of Europe would be 

 looked for under ordinary circumstances. The juniper trees, or white 

 cedars (Cupressus thuyoides) stand firmly in the softest part of the 

 quagmire, supported by their long tap roots, and afford, with many 

 other evergreens, a dark shade, under which a multitude of ferns, reeds, 

 and shrubs, from nine to eighteen feet high, and a thiek carpet of 

 mosses, spring up, and are protected from the rays of the sun. Where 

 these are most powerful, the large cedar {Cupresxusdisticha), and many 

 other deciduous trees, are in full leaf. The black soil formed beneath 

 this shade, to which the mosses and leaves make annual additions, is 



