THE 
AMERICAN GEOLOGIST 
Vol. XXI. FEBRUARY, 1898. No. 2 
ADDITIONAL NOTE ON THE OCEANIC CURRENT 
IN THE UTICA EPOCH. 
By R. RuEDEMANN, Dolgojviile, N. Y. 
(Plate IX.) 
In an article, published in the June (1897) number of this 
journal,* the writer described a series of observations which 
led him to suppose the existence of an ocean current in the 
Utica epoch in the south and southwest of the Archxan mass 
of the Adirondacks. The evidence of the oceanic motion con- 
sists mainly in the parallel arrangement of graptolites and 
cephalopods in a NE-SW direction in the Utica shale, in 
outcrops occurring in the Mohawk valley and on Nine-Mile 
creek, north of Utica.t The observed directions in the last 
locality, which is southwest of the crystalline area, necessitate 
the assumption that the southern part of the latter was a pene- 
plain, which was swept by the current, and that the mantle of 
Utica shale formely extended considerably farther north than 
it does at present. 
C. D. Walcott reached the conclusion before, that the 
Cambrian-Ordovician sea spread over the Adirondack crys- 
tallines, depositing a mantle of sediments. This supposition is 
illustrated by an ideal section (p. 25), in explanation of which 
is said: 
*Vol. XIX, No. 6, p. 367. 
tCf. the sketch map, op. cit. pi. XX 11. 
tSecond Contribution to the Studies on the Cimbrian Faunas of 
North America, Bull, of the U. S. Geol. Survey, No. 30, 1886, p. 24. 
