70 AMADEUS W. GRABAU 



series found directly overlying the f ossiferous marine Ordovicic 

 of southern Pennsylvania, and generally classed by Pennsylvania 

 geologists as "Oneida." This is a gray to white, rarely red, con- 

 glomerate and quartz sandstone with rounded quartz pebbles and 

 characterized by extensive cross-bedding. Its maximum thickness 

 today is in Bald Eagle Mountain, near Tyrone City, Blair County, 

 Pennsylvania, after which locality I originally named it.' This 

 name, however, was preoccupied, and the formation under con- 

 sideration is therefore called the Bald Eagle conglomerate, this 

 ridge being due to the resistant character of this and the succeeding 

 formation. At Tyrone the thickness is 1,319 feet, while thirty miles 

 to the northeast, at the Bellefonte Gap, through the same ridge, the 

 thickness is only 550 feet, and the formation is divisible into a lower 

 hard gray sandstone without pebbles, 170 feet thick, and an upper 

 greenish-gray somewhat ochery and micaceous sandstone with 

 intercalated greenish shales. One hundred and sixty miles north- 

 west from Tyrone, at Buffalo, this formation (Oswego sandstone) 

 is 75 feet thick. It is here a white quartzite lying below the red 

 Queenston shales, and represents only the upper layers of the 

 gradually spreading fan of clastic sediments. In central New York 

 the Oswego is 185 feet thick at the falls of the Salmon River. It 

 there succeeds the Lorraine beds with perfect conformity, some 

 Lorraine fossils extending into the lower Oswego. 



There can be little doubt that these beds represent the northern 

 and western attenuated upper beds of the Bald Eagle conglomerate 

 of Pennsylvania, unless indeed they belong to one or more distinct 

 fans with a source in the north. 



The character of the rock, its cross-bedding, and absence of 

 fossils indicate continental origin, and this is also shown by the 

 nature of the overlap, which is that characteristic of river deposits. 

 The intimate relationship between the Lorraine and the highest 

 bed (Oswego sandstone) of this formation, indicates that the age 

 of this formation is Lorraine. The Bald Eagle conglomerate is 

 everywhere succeeded by the red shales and sandstones of the Juniata 

 formation. In southern Pennsylvania this overlaps the preceding 

 formation and rests directly upon the Eden sandstone. The forma- 



I Science, N. S., Vol XXIX, p. 355. 



