Proceedings of the Albany Institute. 293 



These limestone bands and their associated gneissoid 

 rocks, had been traced to their junction with the great moun- 

 tain masses of Labradorish feldspar, such as formed the 

 highest mountains of northern New York, and were found 

 to pass beneath them, thus proving the more recent origin 

 of the latter, and since the limestone bands rested upon 

 the gneissic rocks, it was evident that these could not have 

 been elevated by outbursts from below. 



Prof. Hall here went on to show how this discoverv de- 

 monstrated in these older formations the truth of the 

 origin of mountain chains which he had brought to the 

 notice of the Institute several years since : viz., that moun- 

 tain elevations were produced by the accumulations of 

 sedimentary materials, and that the highest portions were 

 in reality synclinal axes and not anticlinal axes, as usually 

 supposed. 



He reminded the Institute that some years since, in 

 discussing the question of the age of the older crystal- 

 line rocks, he had announced the fact that in the older 

 granite rocks of Canada, Sir William E. Logan had dis- 

 covered pebbles of stratified rock. These pebbles, there- 

 fore, belonged to a preexisting stratified deposit, or one 

 older than the oldest granite rocks of northern New York 

 and Canada. This evidence proved that below all these 

 crystalline rocks, there were still another set of stratified 

 crystalline rocks ; and that we were still as far as ever from 

 the hypothetical crystalline nucleus of the planet. 



More recently, certain appearances in these crystalline 

 limestones, lately regarded as primary, had led a few per- 

 sons to believe that they contained organic remains ; and 

 Sir William Logan, following up the investigations, has 

 been able within the last j^ear to demonstrate the occur- 

 rence of fossils in this rock. The fossils of these so-called 

 primary formations, belonged to the class of the foramini- 

 fera, a protozoon of peculiar and interesting type. 



