THE FRIENDLY ROCKS 
measures. The Catskill plateau was lifted up before 
Carboniferous times began, so that there is no coal 
in this region. We should have to look overhead for 
it instead of underfoot. When the Catskill plateau 
tose above the waters, Pennsylvania and most of 
the continent to the west was under the sea, receiv- 
ing additional deposits, thousands of feet thick in 
many places, and in due time supporting a vegeta- 
tion that gave us our vast deposits of coal. 
The geologic tornado that brought this hailstorm 
of quartz pebbles, so marked in the conglomerate 
that caps the highest Catskills, seems to have been 
a general storm over a large part of the northern 
hemisphere, as this conglomerate underlies the coal 
measures, both in this country and in Europe. It 
must have occurred in late Devonian or early Car- 
boniferous times. On the top of Lookout Mountain, 
in Tennessee, I gathered a handful of pebbles that 
had weathered out of the Carboniferous sandstone 
that the ages have exposed on the summit. 
An earlier storm of quartz pebbles occurred in 
Silurian times, which formed the Oneida conglom- 
erate in central New York, and the Shawangunk 
range in southern New York. This latter range is a 
vast windrow made up of small pebbles varying in 
size from peas to large beans, cemented together by 
quartz sand. It is several hundred feet thick and 
runs southwest through Pennsylvania into Virginia, 
affording another proof of the abundance of quartz 
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