DILUVIUM. 



279 



CHAPTER XXVI. 



GEOLOGY OF THE UNITED STATES-(Continued). 



ALLUVIAL AND DILUVIAL FORMATIONS. 



Diluvium. — Causes of Diluvial Deposites. — General Deluge. -r- 

 Existing Causes. — Diluvium of Cape Cod. — Alluvium. — 

 Where Found. — Banks of Rivers.— Seas. — Lakes. — Long Isl- 

 and. — Dunes or Downs. — How Found. — Phenomena of. 



Diluvium. — We have defined diluvium to consist of 

 gravel, bowlders,* sand, and loam, and mixed con- 

 fusedly together by powerful currents of water. Of 

 course ii occupies much of the surface throughout 

 a great portion of the United States, and it is im- 

 possible, in a work like the present, to attempt to 

 give a complete description of its localities. It has 

 generally been attributed to the agency of a general 

 deluge, and most geologists have formerly been 

 willing to acknowledge that the phenomena con- 

 nected with it might all have been occasioned by 

 that described in the Bible. There are others, how- 

 ever, such as Mr. Lyell, who attempt to show that 

 these phenomena might all have been produced by 

 causes now in operation, and such as we have 

 pointed out in our chapters on the destruction and 

 formation of rocks, viz., rivers, rain, frosts, &c. 

 This theory, however, is so little satisfactory, that 

 we do not deem it necessary even to attempt to 

 refute it. The liypothesis, however, that the phe- 

 nomena in question are the result of different floods, 

 produced by the elevation of rock strata at various 



* Rocks and stones which have been transported from their 

 original beds, and are, generally, more or less rounded by attri- 

 imi and th^^Qtion of the water. 



