554 



Report of the State Geologist. 



exposures are near, to aid in determining the horizon, which is regarded as 

 Calciferous, though with some hesitation, it being possible that the rock 

 belongs at the base of the Chazy. 



Along the road to Beekraantown Corners, north of Plattsburgh, a long 

 ridge of rock of Calciferous age is exposed, mainly of a flinty, grey dolomite in 

 massive beds lying nearly horizontal. In the bed of Kennon brook, nearly 

 to the Beekinantown line is a considerable exposure, exhibiting some twenty 

 feet of rock, the lower part consisting of dark blue, sparkling dolomites 

 mingled with lighter colored, more sandy beds and thin layers of white, hard 

 sandstone, while above are massive iron-grey dolomites. These beds are w ell 

 down in the Calciferous, higher layers coming in above them in Beekmantown. 



Chazy limestone. The Chazy is excellently exposed on, and southward 

 from Bluff Point, and also north of Plattsburgh, where it lies just to the east 

 of the Calciferous exposures described above. 



Brainard and Seeley have written briefly of the Bluff Point exposures.* 

 The point is a conspicuous topographic feature, rising sharply to an altitude 

 of 170 feet above the lake, and being the only high ground along the shore in 

 the entire county. It is a fault block with a resistant stratum at its summit. 

 Nearly the whole of the middle Chazy and about one hundred feet of the 

 lower division are well exposed. By following along the ridge southward 

 from the point, into Peru, nearly the whole lower division may be brought 

 into the section. The whole series is characteristically fossiliferous. Along 

 the lake shore at the boat landing, the beds shown are well up in the 

 Maclurea division, are much jointed, and contain abundantly a large 

 strophomenoid form, much like R. atiernata, of the Trenton, for which it was 

 taken until the discovery of Maclwrea threw doubt upon the identification. 

 Several other species may also be collected there. 



Just south of Bluff Point is a large quarry, worked in a layer of the 

 lower division in which the crinoidal fragments have a red color. Much 

 stone has been, and is being taken out, which, when polished, makes a 

 beautiful and striking marble. 



The Chazy north of Plattsburgh is in a much faulted district, and has 

 been mapped in detail. At the normal school, beds of lower Chazy age are 

 exposed, which crop out again going north, and are then succeeded, just 

 beyond the racetrack, by the lower Maclwrea beds. These continue along the 

 toad for a distance of nearly a mile, with a sinuous strike. They consist 

 mainly of massive, nearly black limestones, and are largely quarried. AVith 



' Bulletin Geological Society of America, Vol. II., p. 295. 



