r82 NEW YORK STATE MUSEUM 



sions. In other districts, in Clinton county for exanuple, these or 

 similar gneisses are found by themselves and represent the f unda- 

 nLental gneiss, if that formation appears at all in the Adirondack 

 region. From the difficulty of establishing this on the one hand, 

 and of defining any separation from the G-renville rocks on the 

 other, the writer proposed a year ago to refer such rocks to the 

 " Dannemora " formation, the term 'being wholly provisional, and 

 to apply to areas of gneiss where the distinctive rocks of the 

 Grenville are absent, yet whose proper reference to the funda- 

 mental gneiss is wholly doubtful. It is thought likely that these 

 rocks belong with the Grrenville series, but it is a convenience to 

 give them a separate designation for the present. In the western 

 Adirondacks Smyth's recent work has shown an abundance of a 

 granitic gneiss which has unmistakable irrnptive contacts against 

 the Grenville rocks quite like those to be seen to the north in 

 Canada. Whether these granites are the equivalents of those 

 in the eruptive center of the Adirondacks, or of the Dannemora 

 granitic gneisses, or are wholly distinct from either, seems 

 entirely uncertain at the present time. 



