101 
and sandstones of the Uppet Mississippian. The result of this condition 
was that the water in the western branch of Indian creek, a mile or more 
south of Blanche, sank and reappeared in a great spring in the head of 
Blair Hollow a half-mile farther west. <A similar thing occurred less than 
a mile northeast of Blanche and again about a mile and a half farther 
northeast. These sinks are the largest, or most extensive, on the quad- 
rangle. As we approach the heart of the plain farther east the sinks be- 
come smaller and less conspicuous, the stmnaller ones not being shown upon 
the map. 
On the eastern side of Indian creek valley we have large sinks. One 
of these is just north of the Water Works pond. Here the drainage enter- 
ing the sink flows into the pond through Stone spring a few hundred yards 
farther south, entering the Clear creek valley, being diverted from Indian 
creek into which the surface drainage once flowed. Southeast of this there 
is a large sink east of the County Farm which receives the drainage of a 
large region to the north which normally belongs to Indian creek drain- 
age but appears at the surface as a large spring in the north side of the 
branch of Clear creek valley in the N. W. + of Sec. 24, nearly two miles 
south of the sink. The large sinks south and northwest of Leonards 
Schoolhouse have their outlet at Leonards Mill by the house in the head 
of the deep valley a half-mile south of the schoolhouse. Rags put in the 
upper sink are said to reappear at Leonards Mill. 
From the foregoing it will be seen that the headwaters of Indian creek 
have been diverted into Richland creek and Clear creek by subterranean 
Fig. 20. A somewhat diagrammatic profile of a section across the valley of 
Indian creek into a tributary of Clear creek on the right and tributary of Richland 
ereek on the left. he high points on either side of the figure are the old divides 
between the three drainage basins. It illustrates the manner in which Indian creek 
Das been robbed of ifs waters southwest of Bloomington. The dip of the strata has 
favored Richland creek. 
piracy. On the west this piracy is favored by the dip of the limestone and 
on the east it has taken place against the dip, which is very gentle. The 
sinks near the outlets ef the underground streams are large, while those 
more remote and younger are smaller. The smailest are not represented 
