I2 ELIOT BLACKWELDER 
feet in diameter are common. These pebbles and bowlders are not 
sorted or arranged in any way whatever. Large and small are inti- 
mately mingled and are not deposited in layers as in ordinary current- 
laid conglomerates. The long diameters of the bowlders are not 
more often parallel to the stratification than oblique to it. The shape 
of the pebbles and bowlders is significant, since waterworn forms 
were seldom observed and sharply angular bodies are even less com- 
Fic. 1.—Glaciated exposure of bowlder shale in the Yakutat series. The largest 
bowlder is about 6 feet in diameter. 
mon. The great majority of the bowlders have rounded corners and 
edges, but are otherwise rather irregular. 
The beds of conglomerate appear to form the lower part of the 
Yakutat series, but the base on which they rest has not been found. 
Above, they seem to grade into stratified shales which are devoid of 
pebbles, and these in turn are followed by alternate dark shales and 
graywackes. ‘The entire series has been intensely folded and broken 
by numerous faults. Locally, the deformation has been sufficiently 
