CHAPTER II. 



TOPOGRAPHY. 



The great central plateau of Worcester County, averaging about 1,000 

 feet above the sea, lowers a little toward the west, and is accented as it 

 passes into the area under consideration by deep north-south longitudinal 

 valleys, the streams here taking for long distances a north-south course, and 

 it is cut deeply by two great transverse valleys — those of the Millers and 

 Chicopee rivers — which gather all the drainage from the east. With this 

 modification the plateau is continued westward until its l)order forms the 

 eastern edge of the Connecticut Valley. 



The rim of the valley on its west side is the l^order of a similar broken 

 plateau of about the same height, deeply cut by longitudinal valleys whose 

 waters also reach the' Connecticut by two transverse valleys — those of the 

 Deerfield and Westfield (or Agawam) rivers — which are farther south than 

 the corresjjonding valleys on the east, each by about the same distance. 

 The plateau rises along the western portion of the three counties into the 

 Berkshire Hills. It will be noted that the Connecticut Valley includes 

 about all of the broad, low area underlain by Triassic rocks. 



These two plateaus were probably once parts of a continuous ])lain 

 that extended across the Connecticut and other valleys far beyond the 

 limits of the area studied. This plain was formed by erosive agencies 

 which degraded the rociks nearly to sea level. It seems to have been well 

 established by Professor Davis that this degradation took place during the 

 Cretaceous period, and that a later Tertiary elevation enabled the streams 

 to cut down their valleys and clean out the wide lowlands in the soft rocks 

 that border the Connecticut and the eastern branches of the Swift River in 

 Enfield. The peaks and ridges of more resistant rock that rise in these low- 

 lands still reach almost to the level of the old plains, and are remnants of it. 



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