TIME AND CHANGE 
the Andes, the Himalayas, he knows they are young, 
— mere boys. When they get old, they will be cut 
down, and their pride and glory gone. A few more 
of these geologic years and they will be reduced to 
a peneplain, — only their stumps left. This seems 
to hold truer of mountains that are wrinkles in the 
earth’s crust — squeezed up and crumpled strati- 
fied rock, such as most of the great mountain- 
systems are— than of mountains of erosion like 
the Catskills, or of upheaval like the Adirondacks. 
The crushed and folded and dislocated strata are 
laid open to the weather as the horizontal strata, 
and as the upheaved masses of Archean rock are 
not. Moreover, strata of unequal hardness are ex- 
posed, and this condition favors rapid erosion. 
In imagination the geologist is present at the 
birth of whole mountain-ranges. He sees them ges- 
tating in the womb of their mother, the sea. Where 
our great Appalachian range now stands, he sees, 
in the great interior sea of Palzeozoic time, what he 
calls a “geosyncline,” a vast trough, or cradle, being 
slowly filled with sediment brought down by the 
rivers from the adjoining shores. These sediments 
accumulate to the enormous depth of twenty-five 
thousand feet, and harden into rock. Then in the 
course of time they are squeezed together and forced 
up by the contraction of the earth’s crust, and thus 
the Appalachians are born. When Mother Earth 
takes a new hitch in her belt, her rocky garment 
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