554 C. SCHUCHERT SILURIAN FORMATIONS 



Great break. Most of Niagaran absent. 



Silurian. Niagaran series. 



Clinton formation, about 600 feet. 



Silurian. Medina series. 



Tuscarora sandstone, about 290 feet. 



Probable break. 



Ordovician. Ricbmondian series. 



Juniata red sandstone. 530 feet seen. Probable thickness not less than 

 730 feet. 



