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The Cycle of Subterranean Drainage as illustrated in 

 THE Bloomington, Indiana, Quadrangle^ 



By J. W. Beede. 



The Bloomington, Indiana, quadrangle- is the first topographic map to 

 be completed in the cave region of Indiana. It is fifteen minutes square Avith 

 contour interval of twenty feet and scale of 1/62,500, or about a mile to the 

 inch. Careful inspection of the field shows it to be remarkably full and 

 accurate in detail. 



While the cycle of subterranean drainage, as here presented, had not 

 been discussed between us, yet all the various phases of it have been dis- 

 cussed and similar conclusions independently reached by both Trofessor 

 Cumings and the writer as the result of tramps and class excursions over 

 the cave regions of Indiana. The cycle has also been given as lectures, 

 ilhistrated with lantern slides, in our classes. This paper has also had 

 the benefit of Professor Cumings' criticism. 



The physiographic history of the Bloomington region is such as to 

 make this map very interesting, both for tlie remarkable preservation of 

 the older geographic features and for the recent modification of them. 

 Not the least interesting, nor the least important of these, is the subter- 

 ranean drainage. Indeed the fine preservation of the older features is 

 due to the fact that the water has, figuratively speaking, soaked into the 

 old peneplain much as it would into a sponge, confining its work to the 

 solution and honeycombing of the rocks beneath the surface instead of 

 concentrating its energies cutting it into ridges and valleys. 



The whole of the quadrangle, excepting, perhaps, the northwest corner, 

 lies in the driftless area of Soutliern Indiana. The larger streams, except 



1 The title of the paper as shown in the program was "Features of Subterranean 

 Drainage in the Bloomington Quadrangle." After the title had been sent in it was 

 realized that it would be impossible to treat the subjects in mind intelligently without 

 outlining the cycle of subterranean erosion. This outline, of course, overshadows 

 the minor details intended to be covered in the paper, and hence the change in the 

 wording of the title. 



-Price Ave cents. Apply to The Director, U. S. Geological Survey, W:i.sbing1(iii. 

 D. C. 



[G— 2G08S] 



