J atliag e Soe 
New York as the Potsdam sandstone and the Calciferous— 
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T. 8. Hunt on some points in the Geology of Vermont. 225 
brought up against the Levis, and again passes beneath it to 
the east, as in the Swanton section. By the second upthrow, a 
tongue of the Potsdam is carried northward a distance of about 
ten miles in the midst of the Quebec group. The details of 
this structure are fully given in the map and sections of this 
region by Sir William Logan, contained in the atlas accom- 
panying the Geology of Canada. It is to be remarked that 
the lowermost beds of the Levis formation which are seen to the 
It happens then from the facts already set forth, that the 
Potsdam formation, which at its outcrop at the foot of the 
Adirondacks and Laurentides, includes only from 300 to 700 
of sandstone, is represented a few miles to the eastward by 
not less than 2,000 feet of dolomites, sandstones and slates, and 
moreover that occupying a position between the Calciferous and 
hazy formations, which are contiguous at their eastern out- 
regions in the following manner. At the begin- 
a continent was composed of: Laurentian and Huronian rocks, 
_ Partly rising into hills and in part forming a region of slight 
elevation, there were deposited in the surrounding seas the first 
3 fossiliferons beds of the period. To this succeeded a depression 
r waters which surrounded the con 
this being submerged and elevated at intervals, be 
4 with beds which rep 
