115 



or less mixed with clay, and is nut in its usual state a fertile soil. As 

 a consequence of this last fact, it is apt to be covered with a rather open 

 and scanty vegetation. Where under cultivation, unless great care is 

 observed, the steeper slopes gully badly\ Where this soil is fairly sandy 

 end of some thickness, good well water may be obtained for domestic 

 supply. Owing to its usual thinness and indifferent permeability, however, 

 it is not a good conserver of the ground-water, and consequently, in com- 

 mon with the underlying rock, constitutes a poor reservoir for equalizing 

 the flow of streams. 



Some of the larger valleys of the Knobstone region contain consid- 

 erable thicknesses of alluvium. Examples of this type of valley are the 

 Beau Blossom and Salt Creek in Brown and Monroe counties, and the 

 White and Muscatatuck rivers. All of these streams enter the area from 

 the glaciated region, and their flood plain deposits are therefore com- 

 posite, consisting partly of valley-train material, and partly of silt, 

 pebbles and sand washed from the neighboring hills. The nature of 

 these valley deposits, so far as concerns their water-bearing qualities, 

 lias not yet been investigated in a satisfactory manner. Some evidence 

 obtained in the Bean Blossom Valley in the vicinity of Bloomington indi- 

 cates that the valley train in that valley is both deep and amply pro- 

 vided with pervious water-bearing strata. The evidence referred to is 

 the log of a well 70 feet deep, drilled about a year ago in the valley near 

 Bloomington. This well passed through 10 feet of white sand and 15 

 feet of gravel before reaching the depth mentioned. No attempt has 

 been made by the owners of the well to ascertain the maximum yield. 



The geological history of Bean Blossom Valley and of other similar 

 valleys coming out of the glaciated into the driftless area is such as to 

 indicate that these strata of sand and gravel, revealed in the Bloom- 

 ington well, are extensive. It is not necessary to enter into the details 

 of this subject here. They may be found in the writings of Mr. Leverett- 

 of the IT. S. Geological Survey. At least one indication of the immense 

 quantities of water that must be carried as underflow by these valleys 

 is the fact that the majority of the smaller streams and gulleys that 

 emerge upon the sides of the valley do not flow out to the main stream 



'^Shannon. G. IF., Indiana soil typos, Indiana Dept. Geol. and Nat. Res., 32d 

 Ann. Kept., 1908, pp. 99-10.5. 



- Leverelt, Frank. The Illinoi.s Glacial Lobe, Monog. U. S. Geological Survey, 

 No. XXXVIII, 1899. 



