67 



One of the most marked peculiarities in the geology of Vermont, 

 is found in the general dip of the* stratified rocks, which is, with a 

 few trifling exceptions, towards a synclinal axis extending north 

 and south near the center of the Green Mountain range. Along 

 the shore of Lake Champlain the rocks are nearly horizontal, 

 having only a slight easterly dip ; but the dip increases pretty 

 uniformly, in proceeding eastward, till it becomes vertical at a 

 line a little westward of the principal summits of the Green Moun- 

 tains. From this line, for a distance of seven or eight miles cast- 

 ward, the dip of the strata continues nearly vertical. This space 

 embraces the highest part of the mountain range, and. to the 

 eastward of it, the general dip of the rocks is distinctly westward ; 

 but the rocks are here more disturbed, and the dip less uniform, 

 than on the west side of the mountains. 



With regard to the question, whether the rocks, which form the 

 Green Mountains and extend eastward to Oonneeticut river, are 

 truly primary, or aritepalseazoic, as was formerly supposed, or are 

 metamorphic Silurian rocks, which are ne i .vor than the Champlain 

 group, as has been more recently suspected, I would only observe 

 that evidence in favor of the latter opinion was constantly accu- 

 mulating during the continuance of our survey, and has been 

 greatly increased by the labors of Mr. Logan, the provincial geol- 

 ogist of Canada, along our northern boundary. 



The rocks in place, in Vermont, arc, for the most part, covered 

 by the drift formation ; but wherever exposed, they are found to be 

 worn and smoothed, and, usually, striated or scored in the direc- 

 tion in which the drift materials have been transported, which is, 

 generally, from a little west of north to a little east of south ; but 

 this direction is, in various places, very considerably modified by 

 the direction of the ridges and valleys being north and south in the 

 lower parts of the valleys of Lake Champlain and of Connecticut 

 river, but from north-west to south-east, and in some places nearly 

 from west to east, in the valleys and gorges of the Green Moun- 



many cases, entirely disappeared,and the places they occupied become dry laud, One 

 of the most interesting of these mad- beds is in Williamstown. It covers about seven 

 acres, andis in some parts ISfeetdeep. Itisavery pure carbonate of lime, consisting 

 entirely of comminuted fresh water shells. This marl is formed into a paste, moulded 

 in the form of bricks, and then burned in a kiln. Thequicklime thusobtained is quite 

 white, and for most purposes is scarcely inferior to that obtained from the Champlain 

 and Taconic limestone. 



