-x 
_ but instead of curvin 
tion of the magnetic nee i] 
evidence that the ice-flow, at this period of the glacial epoch, 
` pose 
be described as two great loops, one within the other, and wih 
ee ‘ y 
Beginning a little west of the north line of Osceola County, 
vounty, is reached; thence to the northeast, cutting across 
uing parallel with the former, it pursues a southeasterly bea 
760 oe General Notes. [Aug | 
Fifty feet to the south of the above the rock presents a 
equally beautiful scored surface, having, however, but’ one seta 
striz, with a direction south, 70° east. 2 
In the drift which immediately overlies the rock at this plac 
a boulder of red Sioux quartzite, weighing about one hundrei 
pounds, was found; and on the opposite side of the river another 
of the same material somewhat larger. Large boulders of thè 
same material have also been found in considerable abundant 
in the drift for a distance of fifteen miles north from this locality. 
These boulders are in all respects identical, lithologically, with tht 
red Sioux quartzite exposed in the extreme northwestern corte 
of the State, and were, without doubt, derived from that region. 
This evidence, together with the fact that the red Sioux quart 
ite boulders are found in greater or less abundance in both the 
western and southern portions of the State, seems conclusive 
ad a more easterly direction than has been heretofore sup 
The evidence of the third, or last, advance of the ice-sheet it 
Iowa is found ‘in the moraines, which extend nearly across “e 
western portion of the State from north to south. “These maf 
nearly parallel sides,” 3 a 
€ outer moraine may be approximately located as follows: 
along the Middle and South Raccoon into the north part ee 
« Adison County ;”3 thence curving to the east and norte) 
entering Jasper County ;” thence to the north, which cours © | 
until Clear Lake, in the west part of Cerro Gordo 
slightly 
The inner morai à 
Lak lel = 
ne ent rthwest, 
West : ers Iowa from the no ‘ 
gee g to the west from that point and co 
oaral the above bearings an allowance of seven degrees is made for thë j 
2White’s Geolegient ara 2 
3P ; i urvey of Iowa, vol. i. p. ot. 
3 Prof. J. E. Todd, Iowa Hort, Rept, pars ui, 
