122 NEW YORK STATE MUSEUM 



Feet Inches 



layer is a conglomerate, with large but thin black 

 pebbles in a reddish, calcareous matrix; in the 

 lower portion of the bed the pebbles lie flat, but 

 above they are disturbed and may stand on edge ; 



base of Tribes Hill ; 24 feet to -30 



11 Hard, finely granular, gray dolomite, with coarsely 



lumpy surface ; o to 6 



10 Hard, finely granular, massive, gray dolomite, with 

 some calcareous cement, and weathering reddish ; 



a strong chert bed at the summit 24 



9 A ponderous Cryptozoon reef of varying thickness, 

 heavily silicified forming variegated black and gray 

 chert; its upper irregular surface is thinly covered 

 with gray, crystalline dolomite; beneath is a vary- 

 ing thickness of from 4 to 7 feet of finely crystal- 

 line, dark gray dolomite 10 



8 Porous, blocky, gray dolomite, dolomite crystals in 

 calcareous cement, weathering whitish ; many sand 



grains 10 



7 Gray, finely crystalline, porous dolomite, calcareous 

 cement ; drusy cavities with dolomite, calcite and 

 quartz crystals ; frequent quartz grains on the 

 upper and lower surfaces of the beds ; holds thin, 

 twisted chert plates which suggest Cryptozoon. ... 25 



6 Finely crystalline, gray dolomite 35 



5 Medium coarse grained gray dolomite, weathering 

 sandy looking because of calcareous cement; a 



Cryptozoon reef at base 30 



4 Concealed 20 



3 Medium coarsely crystalline, gray dolomite with cal- 

 careous cement ; thin chert seams of Cryptozoon 



character in the upper portion 15 



2 Concealed 30 



1 Light gray, rather coarsely crystalline dolomite, with 

 some rounded grains of quartz sand, in 6 to 18 

 inch layers ; cement in part calcareous ; a thin 

 streak of very black, shaly material near base ; fre- 

 quent, blackish, drusy cavities 30 



This section does not reach the base of the formation, but the 

 lower beds are well shown in the eastern portion of the town with 



