AMERICAN GEOLOGY DECADE OF 1840-1849. 395 



to the westward as they advanced to lower latitudes. On the other 

 hand, the water in the Tropics, being gradually expanded through 

 heat, would tend to flow off toward the polar regions. 



These currents he regarded as having acted throughout all the time 

 since the ocean occupied its present bed, and to them he would ascribe 

 the mechanical distribution of many of the sediments making up the 

 Secondary rocks. Considering only those currents that constitute the 

 Equatorial, the Gulf Stream, and the Labrador Current in the Atlantic, 

 he thought to show that the materials constituting the immense mass 

 of sedimentary rocks between the primary ranges north of the Great 

 Lakes and the Gulf of Mexico, and between the Blue Ridge and the 

 Rocky Mountains, were deposited within the great eddy due to their 

 interference. 



The red sandstone formations extending from Carolina to Stony 

 Point on the Hudson he believed to have been formed through the 

 transporting power of the Gulf Stream, its northward extension hav- 

 ing been cut off by a polar current flowing through the Champlain 

 and Hudson River valleys. The loosely consolidated material now 

 classed as glacial drift he seemed also to regard as having been trans- 

 ported and deposited through the same agency. The coal beds of the 

 eastern and central portions of the United States he regarded as formed 

 at the bottom of the ocean in which great eddies occurred, and where 

 plants brought from the Tropics and other sources would Moat and circle 

 about until they sank. He noted that these beds were based upon a 

 sandstone which at the outcrop of its edges on the coal basins was 

 much coarser and sometimes a conglomerate or coarse pudding stone, 

 while through the center of the basins it was much finer. This fact 

 denoted to his mind a stronger current on the exterior of the coal basins 

 than within its area. 



Concerning the regions over which the polar currents were supposed 

 to have flown, and from whence, as a consequence, were derived the 

 materials for the sedimentary rocks, he could say little from actual 

 observation. Drawing for his materials mainly on the writings of 

 travelers, though acknowledging that such might be faulty, he never- 

 theless pictured a scene of barrenness of the entire region north of the 

 St. Lawrence and Great Lakes and from Newfoundland to the Stony 

 Mountains such as is equaled only by that given by II. II. Hayden in 

 his attempt to account for the deposits of the coastal plain (p. 250). 



Although the quotations from travelers lack that accurate examination that is nec- 

 essary to a determination whether the surfaces thus described have been exposed to 

 the action of violent and long-continued currents, yet they have their weight. When 

 considered in connection with the effects of known physical causes, it is rendered 

 more than probable that the currents under consideration have flowed from the 

 polar regions toward the equator and from the Tropics toward the poles when this 

 continent was beneath the ocean, and that the matter which composed the deposits 

 of the sedimentary rocks of the United States was washed away by these great equi- 



