GLACIAL DEPOSITS 339 



dueed by floating ice and local glaciers as argued by certain 

 Canadian geologists, or by a truly continental ice sheet thousands 

 of feet in thickness, are for our present purposes matters 

 of slight concern. We have more to do with results than 

 methods. Suffice it for the moment, that over the entire north- 

 eastern part of the United States and eastern Canada, all the ex- 

 isting loose materials from rock decay that had been gathering 

 for untold ages were carried bodily northward, westward, or 

 southward, as the case might be. From over a considerable part 

 of southern New England the original residual soils were stripped 

 and dumped into the Atlantic, portions of the transported mate- 

 rial still protruding above sea4evel in the forms known now by 

 the names of Nantucket, No Man's Land, and Block Island. In 

 process of this transfer the rocks were planed down to hard 

 fresh surfaces, over and upon which were deposited new mate- 

 rials from the north. It follows that over this entire glaciated 

 area, estimated by Upham^ as some 4,000,000 square miles, with 

 the exception of a few comparatively insignificant patches here 

 and there, scarcely a foot of clastic matter is to be found that 

 is truly native. "Wherever road cuts or stream erosion favors, 

 the regolith in various conditions of compactness may be found 

 lying directly upon the hard, smooth, and striated rock with 

 which it has perhaps no affinity in composition or structure. 

 The rotten and mechanically triturated detritus of many rocks 

 from many sources more or less admixed by the moving glacier 

 or commingled by resultant streams, is spread out to form the 

 soils on land to which it is as truly foreign as are the emigrants 

 who land to-day upon our shores. The stone wall, built of 

 boulders found loose in the field, may consist of granites, dia- 

 bases, schists, or shales even though the underlying rock may be 

 a limestone; or the wall may be of limestone though the coun- 

 try rock be a gneiss, or slate. A similar distinction exists in 

 the soil itself, which, while it may in part consist of the material 

 of these boulders in a finely divided state, is more likely to con- 

 sist of detritus of softer rocks which yielded more readily to the 

 abrasive force. Sand and gravel or clay, dust or mud, black 

 with organic matter or red-brown from iron oxides, the ad- 

 mixture is ever varying, dependent only on the nature of the 

 materials to the north. But the material of the glacial drift 

 is spread out over the land in a mp^nner far from uniform and 

 ^ Ice Age in North America, p. 579. 



