16 



PALEONTOLOGY OF NEW-YORK. 



Section at Tisdale's Mill, in the town of Warren, Herkimer counttj. 



1. Gray sandstone, forming the upper termination of the group : 60 feet thick. 



2. Shale : thickness? 



3. Sandstone, and shale with iron ore : 20 feet. 



4. Green shale, with arenaceous matter, pebbles, etc. : 25 feet. 



5. Coarse sandstone, with much shaly matter : 10 to 15 feet. 



6. Green shale with fucoids. 



The Oneida conglomerate and Hudson-river group were not observed at this locality. 

 The terminal mass of sandstone attains its maximum thickness of about 70 feet in the vicinity of Steele's 

 creek, south of Mohawk village. 



Section of the strata of the Clinton group, about three miles south of Utica, in the town of JSeW' 



Hartford. 

 The section commences below the quartzose sandstone (which is not seen at this place), and 

 consequently is between 60 and 100 feet below the top of the group, as nearly as can be ascer- 

 tained. 



1. Hard siliceous and silico-calcareous layers alternating with shale, the whole abounding in remains of marine 



vegetation : about 15 feet. These beds form the quarries of Gji.YL,ORD & Norton. 



2. A slope with no rock visible, probably shaly : about 20 feet. 



3. Shales and shaly sandstones, with Butholrephis, Agnostist &c. and iron ore beds. 



4. Upper portion shaly, and the lower part of thinbedded sandstones with wavelines and ripplemarks. The 



fossils are Jlgnostis, JYucula, and some marine plants : about 15 feet. 

 WadsWorth's quarries are in these layers. 



5. A slope, probably over shaly layers of 20 or 30 feet, to Blackstone's quarries, 



6. Alternating layers of shaly sandstone, sandstone and congloinerate with shale : about 25 to 30 feef . 



Blackstone's quarries are in these beds. 



7. Oneida conglomerate. 



;j*. The absolute contact of the upper beds with the Oneida conglomerate is not seen at this place. 



It will be observed that in all these beds there is no evidence of the existence of the Medina 

 sandstone, unless it be in the diagonally laminated red sandstone, and the grey sandstone with 

 pebbles near the base of the group. 



From the point last noticed, it is difficult to obtain good sections of the group till we go westward 

 to Wayne county, where its characters are greatly changed, and where the Medina sandstone is 

 in great force. 



The greater part of the group is well developed on a small stream near the former Shaker 

 settlement at Sodus bay, and, more perfectly, just above the lower falls of the Genesee. At this 

 place the mass admits of the following subdivisions in the ascending order : 



1. Green shale resting on the Grey band, destitute of fossils, very fissile and unctuous. 



2. Oolitic iron ore with concretions, fragments of shells, corals, etc. A few thin layers of impure limestone or 



shaly sandstone sometimes intervene between the shale and iron ore. 



3. Pentamerus limestone, a siliceous or calcareous mass with thin sandy layers, often having the character of 



shaly sandstone : it also contains bands of hornstone or chert, consisting mostly of silicified fragments of 

 fossils. This part of the mass is distinctly marked by the presence of large numbers of the Pentamerus 

 oWong-Ms, sometimes crowded together, forming a band a foot or more in thickness, or distributed through 

 the whole rock. 



4. A green shale similar to that below, though of a less deep color. It also exhibits one or two bands of lime- 



stone, composed mostly of shells of Atrypa hemispherica, which preserves its beautiful pearly lustre. It 

 contains graptolites ; and in some localities where these abound, the mass is black. 

 In this relative situation in Wayne county, the second bed of iron. pre. oc?.urs. T,h* or^ is more perfectly 



