452 ELEMENTARY GEOLOGY 
land and Pennsylvania, or to the condition of low 
mountain ranges such as those now seen in New 
England. This destruction of the mountains con- 
tinued throughout the greater part of Ordovician times, 
until they were probably quite reduced in elevation 
and subdued in outline. Then came the mountain 
development which affected New England, certainly 
as far east as the Connecticut River, and_ possibly 
even as far as our present coast-line. How far south 
and north of this the mountain growth extended, is 
not yet determined, but the folding was widespread. 
We know that this mountain formation occurred at this period, 
because the Ordovician rocks, formed distinctly in the sea, are 
now extensively folded and metamorphosed, while the strata of 
the next succeeding period, also deposited in the sea, are not 
so disturbed. These later rocks rest unconformably upon the 
tilted edges of the mountain strata. Hence between the time of 
formation of the Ordovician and the deposit of the Silurian rocks, 
the former were uplifted and folded. 
The growth of this mountain range was intense, 
and the chain of peaks reached to great heights. At 
present these mountains have been so worn and denuded 
by the removal of their upper portions, that they are 
dissected so as to reveal even their very roots. The 
Green Mountains, Berkshire Hills, Taconic ranges, the 
mountains of western Connecticut, and the rocks upon 
which the city of New York is built, represent the 
roots of parts of these ancient mountains. 
