m 



since there is evidence tliat collapse lias bronyht the present stream to the 

 surface for some distance below the "Gulf" where it now escapes. 



■The collapse of the month of tlie ca^^eni is brought about by tlie in- 

 creased Avidth and lieiglit due to solution and abrasion, the fall of slalis 



I'ig. 6. Stony Spring, Bloomingtoa vvaterwoi'ks. During freshets the water 

 flows out all around the foot of the hill shown in the picture and even farther to 

 the left. The cavern containing the stream is here collapsed, blocking the outlet. 

 When the cave fills with water it breaks out wherever It can find an opening. The 

 water comes from the former drainage basin of Indian Creek and now enters the 

 head of Clear Creek. 



from the roof and by the lowering of the channel until the roof, unable to 

 support itself, Anally falls. This collapse of the lower portions of caverns 

 bringing more and more of the subterraueaii stream to light maj' be, and 

 frequently is, going on at the same time that tlie upper reaches of the 

 stream are being converted from surface into subterranean drainage. This 

 is true of nearly all the largest outlets of subterranean drainage in the 

 Blooniington region. Stone spring at the Water Works, Shirley spring and 

 Leonards spring, southwest of the Water Works, and Bhiirs spring, just 

 northwest of Stanford Station, all show this phenomenon, while the uiiper 



