412 G. L. COLLIE OHDOVICIAN SECTION NEAR BELLEFONTE 



Feet 



5. Black slaty shale, with a few thin lenses of limestone, containing Plec- 



tambonites sericeus, etcetera. Horizon A-13 3.5 



6. Light gray limestone filled with veins and nodules of calcite, containing 



Plectambo7iites sericeus, etcetera. Horizon A-14 56 



7. Dark slaty shale containing Protowarthia cancellata, Salpingostoma expansa, 



etcetera. Horizon A-15 6 



8. Shaly black limestones alternating with thin beds of crystalline gray 



limestone, containing 7Vemaf'is^erwma/is, etcetera. Horizon A-16. . 181 



Total thickness of the Trenton formation 603 



Total thickness of the Ordovician limestones 5,752 



GROUP V.— UTICA STAGE 



Laminated dark-colored fissile shales, alternating with a few thin beds of 

 limestone near the base of the formation ; contains Tnarthrus hecki, 

 etcetera. Horizon B-1 90 



Soft red and brown shales containing nodules of iron pyrites, at the top 

 alternating with thin beds of sandstone containing Triarthrus hecki. 

 Horizon B-1 210 



Soft ferruginous shales alternating with fissile black and brown shales, 



containing oval nodules of iron pyrites unfossiliferous 250 



Brown, red, and green shales, quite soft and much broken by cross-joint- 

 ing ; the shales contain numerous nodules of iron pyrites, apparently 

 unfossiliferous 100 



Total thickness of the Utica formation 650 



GROUP VI.~LORRAINE STAGE 



1. Soft gray and brown shales alternating with black slaty shales ; in the 

 upper portion of the formation thin beds of sandstone and ferru- 

 ginous limestone (rotten-stone) occur at frequent intervals ; contains 

 CyrtoUtes ornatus, Byssonychia cincinnatiensis, etcetera. Horizon B-2. 350 



Total thickness of the Utica and Lorraine shales 1 ,000 



Total thickness of the Ordovician rocks in the Bellefonte 



section 6, 752 



The Faunas and Their Relationships 



Horizon A-1, the lowest fossiliferous horizon, occurs in a dark, iron- 

 stained, oolitic limestone 400 feet above the lowest exposure of rock in 

 the section. The fossil-bearing horizon is only a few inches in thick- 

 ness ; the fossils are obscure and usually in a worn and comminuted 

 condition, all of which renders their identification difficult. The onl}^ 

 recognizable species are O'phileta cowplanata Vanuxem and a small 

 Ophileta similar in general appearance, probably 0. levata Vanuxem. 

 The facies of this fauna clearly indicates the Beekmantown age of this 

 horizon. 



