Geology and Mineralogy. 299 
the oldest rock formations of the State, as well as of the eastern 
tiles, a 
presence of the Postdam and Calciferous sandstone and the Chaz 
rocks of the lower division of the Laurentians consist of 
black hornblendic, gray garnetiferous and coarse feldspathic and 
quartzose gneisses, with extensive beds of magnetic iron ore, 
se are succeeded by massive beds of labradorite rock—the 
limestone in the eastern counties of northern New York has been 
believe by all geologists. = ie 
= Uaring, in 1866, been occupied in some critical examinations of 
'¢ Tegion in the neighborhood of Port Henry and Westport, I 
Pasha a part of the lower Laurentian series of strata, but uncon- 
ormably overlaid the upturned edges of the gneissic beds of that 
seg of the system. Neither does it conform to the upper or 
i Having had occasion to pass 
;ver the same region almost annually since that period I have 
8 flanking the Laurentian rocks to the southward, and is — 
th vously present in the town of Minerva, and it is apparently 
* *ame belt which is known in Warren county. From the latter 
y it has been reported as containing Eozoon. 
