r. j 
ote 
1887] Geology and Paleontology. 759 
The second glacial current was from the northwest to the 
southeast. We appear to have sufficient evidence of its direction 
in the glacial scored rocks, and the boulders found in the drift 
in different portions of the State. 
The direction of the striz observed upon the Burlington lime- 
stone, near Burlington, in the extreme southeastern portion of 
the State, was south, 22° east. 
Up to last year, this was the only locality known in Iowa 
planed and scored by glacial action. The size of this surface was 
ten feet by sixteen feet, and the parallel striæ have the direction 
south, 73° east. Near the centre of this surface? one large 
ttom slopes gradually upward to the north; and what is of 
Peculiar interest is the fact that the bottom, and particularly the 
north side, is beautifully smoothed and striated, while the south 
side, which is very abrupt, shows scarcely a trace of the smooth- 
Ing and striating action of the ice. The trend of this groove 1s 
poy east. The north side of the groove presents several 
. 
of which were taken, with the following results : 
’ ? 
T e o No. 5, north, 7114° east. 
is LS great Variation in ie Sars of the striz at this poig 
_~leved to have been caused by a deflection of the relative y 
mt ice from its normal course by some local obstruction. 
rik bank Geological Survey of Iowa, p. 94- In these cases no allowance is made 
o appenctic variation, : 4 
ioe is from thirty to forty feet above the water in the Jowa River. 
