208 The Taconic System. [Oct., 



Again, if they belong to the New York system and are merely 

 the lower subdivision of it, why is it that they are so much thicker 

 than the whole New York system put together? How happens 

 it that there is withal such a great preponderance of slate? There 

 are naked and continuous beds of slate thicker than the whole 

 New York system, which may be seen under conditions which 

 show that there is no repetition of masses. 



Why is it that the Stockbridge limestone, if it is but a repeti- 

 tion of, or identical with, the lower limestones of the New York 

 system, is underlaid and overlaid also with slate; or, in other 

 words, is inclosed in slate, whereas those limestones referred to 

 are underlaid by a sandstone? If the Taconic rocks are raeta- 

 morphic, where are the igneous rocks w^hich have produced the 

 change between the Hoosick mountain in Adams and the Hudson 

 river? 



The preceding questions we regard important, and ought to be 

 answered by those who maintain the identity of the series be- 

 tween the Green mountain range, the Champlain and Hudson val- 

 leys, with the New York system. 



The history of the opinion relating to the Taconic system may 

 not be out of place. In 1837-8, we taught in our lectures at 

 Williams College nearly the same doctrine which is now main- 

 tained by Messrs. Rodgers, namely, that the granular quartz, and 

 the limestones, marbles and slates of Berkshire, were but exten- 

 sions eastward of the lower New York rocks. We were led at 

 the time to adopt this view from some facts which fell under our 

 observation at Burlington, Vt. We attempted at the time to 

 work out in detail the rocks under the guidance of this doctrine. 

 We found, however, that we were opposed by facts M^hich could 

 not be interwoven together, and hence we were led to abandon it 

 for the one we have since published. The first hints that were 

 published in regard to this system appeared in Disturnel's State 

 Register. We were requested to write a brief article on the 

 geology of the state for that work. In making up our notes for 

 this object, we found it necessary to fix upon some general subdi- 

 vision of the rocks which belong to the state. We drew up an 



