432 



Report of the State Geologist. 



nella, sp., Tentaculites, sp. The total thickness of the Oriskany exposed in 

 this ridge is about one hundred feet. 



There are several ledges of Catskill shaly and Lower Pentamerus lime- 

 stones in Mr. Cuddeback's lane, south of ridge 66, but their character is the 

 same as in the outcrops previously described. 



The accompanying sketch gives the section from east to west across Mr. 

 Cuddeback's land. 



>' 



c 



Figure 11. Section across the Helderberg ridge, two miles southwest of Otisville. 



The approximate thickness of the different members, as exposed in this 

 section, is : 



Oriskany shaly and cherty limestones, 75 feet + 



Catskill shaly limestone, 15 " + 



Lower Pentamerus limestone, 65 " 



Tentaculite limestone, 45 " + 



The next good series of Helderberg exposures is four miles southwest of 

 Otisville, and one mile slightly northeast from Rose Point. The greyish blue 

 Helderberg limestone forms a series of low ledges at the southern end of a 

 large ridge. These ledges are in a field west of the road, opposite a large 

 pond. About fifty feet of cherty limestone of Lower Pentamerus age, are 

 here exposed. Fossils are abundant, and nearly all of them are silicified. 

 These layers are also probably near the transition from the Lower Pentamerus 

 to the Catskill shaly limestones. 



The following species were determined: Spirifer macropl&wrus (common 

 in the upper layers), Orthis plcmoconvexa, Trematospira formosa, Orihis 

 biloba (common), Cyrtma Dalmani, Leptwna rhomboidalis, Dalmanites 

 in icru rus, Spwifer arrectus, Pentamerus galeatus, Spirifer perlameU6sws t 

 Stropheodonta, sp., Bryozoans on Loxonema, Lichenalia, sp., Rhynchonella, 

 sp., Zaphrenti8, Mwosites, Orihothetes, sp., Lingula, sp., Atdopora, *]>.. 

 ( Itulopovcb) sp. 



