MiLLWARD : Fossils from Meadville, Pa. 487 



Age of the Formations. 



The Sharon conglomerate belongs to the Pennsylvanian, and has 

 been assigned a place in the upper part of the Pottsville by David 

 White, Bulletin Geological Society of America, Vol. XV, 1905. 

 The other formations of this section, excluding the Riceville, were 

 classed by Dr. I. C. White in the report cited above as the sub-con- 

 glomerate formations, which he divided into the 



Shenango group, 

 Meadville group, and 

 Oil Lake group. 



The Shenango and Meadville groups are correlated by Dr. White 

 with the Cuyahoga Shales of Ohio, and the Oil Lake group with the 

 Berea Grit of Ohio, both of which belong to the Waverly (Missis- 

 sippian). The Chemung facies of the fauna of the Riceville shale 

 was recognized by Dr. White, but the position of the formation was 

 not definitely fixed in the report cited. 



\x\ the Bulletin Geological Society of America, Vol. XIV, page 

 177, 1903, Professor Williams has correlated the Shenango, Meadville, 

 and Riceville with the Bedford, Berea, and Cuyahoga of Ohio and 

 the strata between the Chemung and Olean of New York. Li regard 

 to the fauna, he states, on page 184, that Chemung species are not 

 found above the Riceville shales, the pure Waverly fauna coming in 

 above that formation. 



Professor Stevenson, Bulletin Geological Society of America, Vol. 

 XIV, page 42, 1903, places the Shenango and upper Meadville in 

 the Mississippian, and correlates them with the Logan and the Waverly 

 shales (Herrick) of Ohio. The Lower Meadville, Sharpsville, Orange- 

 ville, and Oil Lake he places in the Devonian, and correlates them 

 with the Cuyahoga and Berea of Ohio. The Riceville and Venango 

 he correlates with the Chemung of New York. 



Girty {Science, n. s.. Vol. XIX, no. 470, Jan. i, 1904, p. 24) has 

 traced the Berea of Ohio into the Cussewago sandstone of north- 

 western Pennsylvania. 



As may be seen from the above lists of fossils, most of the faunules 

 contain some Chemung species, but those of the strata above the Rice- 

 ville are closely related to the faunas described from the Waverly of 

 Ohio. 



