538 



CENOZOIC TIME — MAMMALIAN AGE. 



In southwestern Vermont the granite of a high hill between Stamford and 

 Pownal, which is almost as high as the Green and Hoosac Mountains lying to 

 the east and southeast, has been carried southeastwardly over the western sides 

 of these mountains, and over a very hilly region, into and nearly across the 

 State of Massachusetts. 



Large boulders strew thickly the north shores of eastern Long Island, which 

 are the crystalline rocks, trap, and sandstone of New England. Southern New 

 York is strewed with pebbles and boulders of the Azoic rocks to the north. 

 South of Lake Superior there are boulders which have come from the north 

 shore of the lake. 



Attendant phenomena, — Groovings or Scratches. 



Besides the travelled stones and earth, there are deep scratches 

 or groovings in the rocky surface of the country across which the 

 stones were carried, over the regions of quartz, slate, and other 

 rocks not undergoing easy decomposition in New England, New 

 York and other parts of the country. The rock when uncovered 



Fig. 829. 



Drift groovings,. or scratches. 



is often scored all over with these groovings. The very hard quartz 

 rock of Vermont and New York was not able to resist the powerful 

 agent. 



Character of the grooving and wear of rocks. — The groovings • are (1) 

 long, straight, parallel lines, often like the lines of a music-score, 

 or broad scrapings, ploughings, and • gougings of the surface. 

 The scratches vary from fine lines to furrows half an inch deep,- 

 and occasionally occur a foot deep and several feet wide, as at 

 Rowe in Massachusetts, or even two feet deep, as on the top of 



