294 INDEX TO TI-IE STRATIGRAPHY OF NORTH AMERICA. 



The section near Altoona, as determined by Butts/" is as follows: 

 Section of Devonian rocks near Altoona, Pa. , 



Kindle *"' comments in detail, with faunal lists, on the faunas of the Altoona 

 section. 



The Devonian formations in New Jersey present different characters in two 

 districts, the Delaware Valley and Green Pond Mountain. Klimmel ^^^° states: 



The Devonian formations of the upper Delaware Valley are of marine origin and are 

 chiefly fossihferous calcareous shales and hmestones having a thickness of about 1,000 feet. 

 Those of the Green Pond Mountain region are chiefly arenaceous shales, sandstones, and 

 conglomerates, carrying comparatively few fossils and aggregating over 4,000 feet in thickness. 



The Helderbergian or lowermost Devonian faunas in New Jersey are essentially the same 

 as those in New York, and the same faunal zones are recognized. The first formation carrying 

 these faunas is the Coeymans limestone. 



Goeymans limestone. — In the Nearpass section the Coeymans Hmestone has an estimated 

 thickness of 40 feet, though only the lower beds are exposed. It rests conformably upon the 

 Manhus hmestone, from wliich it differs lithologically in its coarser and more crystalline 

 texture and hghter color. Frequently more or less chert is mingled with the hmestone. The 

 Coeymans fauna is far more prolific than that of the Manlius and difllers markedly in compo- 

 sition, the most characteristic species being Gypidula galeata. A coral bed carrying more or 

 less completely sihcified masses of Favosites Jielderhergise and a concentrically laminated 

 stromatoporoid occurs in the base of tlie formation. 



Stormville sandstone. — In the southern half of the Wallpack Ridge in New Jersey, a thin 

 sandy layer occurs at the top of the Coeymans hmestone. It is in general an inconspicuous 

 formation, owing to its thinness and heav}^ deposits of glacial drift. It becomes more con- 

 spicuous toward the south and according to Wliite " it gradually replaces the overlying cal- 

 careous and shaly strata until it occupies the entire interval between the Coeymans limestone 

 and the Oriskany sandstone. It has not been recognized in the Nearpass section near Tristates 

 nor at any point north of Hainesvillc, N. J. 



New Scotland heds. — The New Scotland beds, which overlie the Coeymans hmestone in 

 the Nearpass section, consist of about 20 feet of a very hard cherty limestone followed by a 

 series of calcareous shales, having an estimated thickness of 140 feet. Nowhere ia the State is 

 there exposed a continuous section of these beds as is the case with several of the lower forma- 

 tions. The fauna is a prolific one and is especially characterized by the abundant representa- 

 tion of the genus Spirifer. Its differences from the Coeymans fauna are of such an essential 



o Second Geol. Survey Pennsylvania, Rept. G6, 1882, pp. 132, 133. 



