264 A. J. Jukes-Broicne — The Bovey Deposils. 



the manner of peat beds in Europe and the more northern parts of 

 America. But it is a fact that south of a certain line of latitude in 

 the United States peat-forming mosses do not flourish, and that they 

 do not occur in the great swamps of Virginia and Carolina. These 

 are forest-swamps with an undergrowth of cane-brakes (Armido), 

 ferns, and other annual plants in the drier parts. In the Great 

 Dismal Swamp the most conspicuous trees are the Taxodium, which 

 grows to a height of about 50 feet, the White Cedar [Cupressus 

 thyoides), which reaches to 30 feet, and the Black Gum {Nyssa 

 denticulata), growing to a height of 40 or 50 feet ; and in some parts 

 a climbing grape-vine forms a dense thicket between the trees. ^ 



It is certainly, then, to the Great Dismal Swamp on the borders of 

 Virginia and IN'orth Carolina that we should look for a modern 

 counterpart of the conditions under which the Bovey lignites were 

 formed. There is no better account of this swamp than that written 

 by Sir C. Lyell and published in his Travels in North America, 1842, 

 and there is an excellent summary in his Principles of Geology ^ 

 which may here be quoted. 



This is "an extensive swamp or morass, 40 miles long from north 

 to south and 25 wide between the towns of Norfolk in Virginia 

 and Weldon in North Carolina. It has somewhat the appearance of 

 an inundated river plain covered with aquatic trees and shrubs, the 

 soil being as black as that of a peat-bog. It is higher on all sides 

 except one than the surrounding country, towards which it sends 

 forth streams of water to the north, east, and south, receiving a supply 

 from the west only. 



"In its centre it rises 12 feet above the flat region which bounds it. 

 The soil to the depth of 15 feet [in some places] is formed of vegetable 

 matter without any admixture of earthy particles . . . 



"The surface of the bog is carpeted with mosses and densely 

 covered with ferns and reeds, above which many evergreen shrubs and 

 trees flourish, especially the White Cedar {Cupresstis thyoides), which 

 stands firmly supported by its long tap-roots in the softest parts of the 

 quagmire. Over the whole the deciduous Cypress {Taxodium distichtim) 

 is seen to tower with its spreading top, in full leaf in the season when 

 the sun's rays are hottest, and when, if not intercepted by a screen of 

 foliage, they might soon cause the fallen leaves and dead plants of the 

 preceding autumn to decompose, instead of adding their contributions 

 to the peaty mass. On the surface of the whole morass lie innumerable 

 trunks of large and tall trees blown down by the winds, while 

 thousands of others are buried at various depths in the black mire 

 below." 



From Professor Shaler's account of the Swamp we learn that it 

 rests on unfossiliferous sands derived from a bordering Pliocene 

 deposit, and that there is no great depth of lignitic or freshwater 

 material below the swamp-area. It would seeni that the subsidence 

 which led to the formation of the ' Dismal Swamp ' was of short 

 duration, but if it had been of greater extent, without bringing in the 



1 See N. S. Shaler, " Ou the Freshwater Morasses of the United States," ia 

 Tenth Ann. Rep. U.S. Geol. Survey, 1888, pp. 261-339. 

 • 10th ed., 1868, vol. ii, p. 505. 



