PIKE COUNTY. 27 



KinderJioolc Group. One of the best exposures of this group in this county, 

 is at the point of the bluff, just above the village of Kinderhook, from whence 

 it has received its name. The following is the section at this point : 



FKET. 



Loess capping the bluff 20 



Burlington limestone 15 



Thin bedded, fine grained limestone 6 



Thin bedded sandstone, and sandy shales 36 



Argillaceous and sandy shales, partly hidden 40 



The three lower beds of the above section belong to this group, and there 

 are some twenty feet or more of still lower beds, which do not appear above 

 the surface here. The thin bedded, fine grained limestone, which lies at the 

 top of the series here, resembles the fragmentary limestone at Burlington, 

 Iowa, which, at that locality, contains Chonetes Fischeri, Rhynchonetta pustu- 

 7osa, and Spirifer biforatus, but no fossils were found in it here. The thin, 

 bedded sandstones below this, however, abound in fossil shells, belonging to 

 the genera Aviculopecten, Spirifer, Orthis, and Productus, mostly identical with 

 those from the gritstones at Burlington, which belong to the same horizon. 

 The Argillaceous shales at the base of this group, have afforded no fossils as 

 yet from any of the localities examined in this county. From Kinderhook 

 southward, along the bluffs on the west side of the county, this group is more 

 or less exposed below the Burlington limestone, which forms the upper escarp- 

 ment, and at Rockport, nearly the whole of the group may be seen, forming the 

 following section : 



FEET. 



Loess capping the bluff 20 to 30 



Arinaceous limestone and shale 16 



TJnexposed strata 20 



Green and blue clay shales 30 



Covered slope to the level of the road 32 



On our first visit to this county, in 1853, we found at this point a brecciated 

 oolitic rock, about three feet thick, which receives a high polish and makes a 

 beautiful marble. At a more recent visit, we did not find it exposed, and it 

 is probably included in the twenty feet of unexposed strata, below the arena- 

 ceous beds near the top of this section. This arenaceous limestone contains a 

 few fossils, among which are Spirifer Marionensis, S. hirtus, Productus pyxi- 

 datus, P. arcuatus, Rynchonella Missouriensis, and Chonetes geniculata. About 

 two miles below Atlas, the Burlington limestone caps the bluff, and we find the 

 Kinderhook group outcropping below it, affording the following section : 



FEET. 



Burlington limestone 12 



Magnesian limestone 8 



Unexposed t 18 



