NORTHERN END OF THE HELDERBERG PLATEAU 67 



7 Tellinomya nucleiformis Hall (r) 



8 Megambonia aviculoidea Hall (r) 



9 Loxonema Fitchi Hall (rr) 



10 Modiolopsis (?) dubia Hall (r) 



11 Camarocrinus stellatus Hall (r) 



HOWE'S CAVE SECTIONS 



Just west of the station on the northern side of the railroad 

 track are large quarries in the Tentaculite and Pentamerus lime- 

 stones. Below the track are several quarry openings in the lower 

 part of the waterlime, part of which are abandoned, and still 

 lower a quarry in the green Clinton shale, which is sold for 

 gypsum. The following section is from the level of the Cobleskill 

 to the top of the Pentamerus ledge in the upper quarry. The 

 Hudson formation is not exposed along the Cobleskill at Howe's 

 cave; but Hudson sandstones form a small fall in the creek more 

 than one half the distance from Howe's cave to Central Bridge, 

 .and these shaly sandstones and shales are exposed in a railroad 

 cut a little west of Central Bridge. 



Feet 



VIII A 1 Covered from the level of the Cobleskill at the 32=32 



suspension footbridge to the base of the green 

 shales in the gypsum quarry. 

 A 2 Clinton green argillaceous shales containing 24=56 



numerous nodules of iron pyrites. The lower 5^ 

 feet are quite strongly crumpled, the folding 

 showing very well on the wall of the quarry, 

 while the upper layers are nearly horizontal, 

 with only a little crumpling at their base. 

 Farther west, at a point nearly below the old 

 waterlime quarries, 33J feet of Clinton shale 

 is exposed, which extends to within 4 feet of 

 the creek. Darton gave the thickness of the 

 Clinton at this locality as " about 40 feet," 

 and stated that "the Hudson river shales 

 [are] exposed a short distance below." 1 



H3th an. rep't state geologist. 1893. p. 218-19. 



