The Southivestward Bowlder Trains . 
495 
Pecatonica basins in Rockton and Owen townships, west of 
Rock river. 
That the glacial movement which produced these striations, 
molded the elliptical drift ridges, and dispersed the quartzites 
along these westerly lines did not reach the border of the drift¬ 
less area is uniformly attested by the fact that all these phenom¬ 
ena cease far within the limits of the drift area. Its outer 
margin at successive stages in its occupancy of the area appears 
to be marked by belts of kame-like deposits that cross the area 
between the Rock and Sugar river valleys in Wisconsin, and are 
continued to the southeast on both sides of the Rock in north¬ 
ern Illinois. The position of these belts is indicated on the map 
of the southwest train. The outer of these belts appears on the 
crest of the high limestone ridge south of the ridge forming the 
peripheral border of the bowlder train in the northeast corner 
of Green county, Wisconsin. It forms a series of broad gravel 
ridges in the basins of the eastern tributaries of the Sugar river 
on the line between Green and Rock counties, and is strongly 
developed across the low col between two adjacent basins 
draining respectively into the Rock and Sugar rivers in the 
south half of Rock county. Farther south it appears as a series 
of broad ridges, semi-morainic in part, but mainly of gravel or fine 
sand, which cover the west side of the Coon Creek valley in 
Newark township. Low gravelly ridges continue the belt over into 
the Pecatonica basin and a light line of gravel ridges crosses the 
divide in the same general direction into the valley of the Rock 
north of Rockford. 
Apparently correlated with this is a belt of thickened drift, 
kame-like on lower levels and morainic in places on the ridge 
crests, that appears on the south side of the Pecatonica from 
Rockford west to the Stephenson county line. It here disap¬ 
pears on the south bank of the river and has very slight develop¬ 
ment on the north side of the valley. It apparently marks the 
south margin of a southwestward protrusion of the ice lobe 
which moved up the broad low valley of the Pecatonica. 
A second belt starts near the same point as the last and 
crosses Rock county diagonally to the river valley at Beloit. 
Its main development, like the last, is in the low lands, but is 
