STRATIGRArillC TAXONOMY 



Canadian section at Belief ante. Pennsylvania' 



Upper Stones River — the lower 230 feet consisting of thin, 

 irregularly bedded, light and darker gray, sometimes dove, 

 fine-grained pure limestone. Locally very fossiliferous. 

 Base of Ordoviciou. 



Break 

 Belief onte dolomite (new) 



13. Mostly argillaceous, highly magnesian limestone, compact, 

 often laminar, easily weathering, light gray, unfossilifer- 

 ous. Upper 300 feet poorly exposed 400 



12. Yellowish gray or drab, generally fine-grained and occasion- 

 ally laminated dolomite, alternating with fewer ledges of 

 comparatively dark, finely crystalline dolomite, both gener- 

 ally in rather even layers of medium thickness. Nodules 

 of chert occur but not commonly except in some massive 

 ledges 800 to 900 feet beneath the top. The cherty bed. 

 which is well exposed at the Central Railroad of Pennsyl- 

 vania depot, contains also some irregular layers in part or 

 wholly filled with rounded quartz grains. Others show 

 numerous fragmentary remains of trilobites and occasion- 

 ally gastropods, like Hormotoma artemesia (Billings), but 

 all so firmly cemented to the matrix that they can not be 

 determined satisfactorily 1,745 



657 



Feet 



Total thickness of Bellefonte dolomite 2,145 



Axeman limestone (new) 



Feet 



11. Thick and thin bedded, nearly pure limestone, dark in color, 

 frequently stained with iron oxide and ranging in texture 

 from compact to distinctly crystalline. The fine-grained 

 layers are often mottled with irregularly inosculating, light 

 colored argillaceous spots. Others are oolitic limestone 

 conglomerates. Many of the layers are abundantly fossil- 

 iferous. Small Ostracoda (suggesting Leperditclla , Apar- 

 chites, and Primitia) and Hormotoma gracilens are some- 

 times common in the upper 50 feet. The most character- 

 istic fossils of the formation, and especially abundant in 

 the lower 40 feet, are Prototvarthia rossi, Liospira strigata, 

 Maclurea affinis. and a trilobite like Bathyurus amplimar- 

 gvnatiis 1 5S 



Total thickness of the Axeman limestone 158 



