178 Frank Carney 



tic coast the combined area of swamps is approximately 20,000 

 square miles. ''^ The everglades of Florida and the Dismal Swamp 

 section a little north are the most extensive of these coastal swamps. 

 In these places, vegetation is luxmiant, and as it passes from one 

 generation to another the remains do not decay as plants decaj^ 

 mider the atmosphere. It is a common observation that any form 

 of wood lasts longer when kept moist or kept entirely under water. 

 Fence posts will rot completely off above the ground and show 

 verj^ little decay underneath. This slow decay of plant remains 

 is supposed to be the first stage of making coal. 



Possibh' another error as to the origin of coal is the prevalent 

 idea that our coal beds represent great forests of ferns, palms, and 

 other tropical vegetation. While vegetation of this type would 

 furnish more quickly the amount of vegetable matter necessary 

 to make coal, at the same time it is more probable that the lower 

 forms of plant growth contribute more largely to the coal seams. 

 Certain mosses which thrive at the present time in cool, moist 

 climates appear to produce peat more rapidly than do the higher 

 forms of plants. This is true to such an extent that it is customary 

 to speak of peat as the product of sphagnum moss. ''Under 

 favorable conditions a foot of peat may accumulate in ten years 

 or even less but the usual rate is probably much slower."" In 

 Alaska, in many of the northern states, and through parts of 

 Europe, and even in Ohio, peat has been forming in recent 

 geologic times, and these swamps are still growing. 



The swamp areas, bordering ocean basins, lie in tracts that are 

 slightly above sea level. A study of the succession of deposits in 

 the coal horizons suggests a similar relationship of the land to the 

 sea. A delicate balance always exists between water level and 

 swamps. While most plants that grow thus luxuriantly require 

 permanency of moisture, at the same time a slight over-supply of 

 moisture checks growth. Any changed relationship in the atti- 

 tude of land areas to surrounding oceans is observed first along 

 the borders. Therefore these marshy tracts may be submerged 

 by land movement, the vegetation checked, and the swamp 

 become a basin in which sediments are being deposited. Without 



^^ N. S. Shaler, Geographic Monographs (1895), "Beaches and Tidal Marshes of 

 the Atlantic Coast," p. 159. 

 ^' Chamberlin and Salisbury, Geology, vol. ii, (1906), p. 571. 



