STRUCTURE OF THE DRIFT BORDER. 61 



that region. The writer had opportunity to examine the material thrown 

 out of a well at the residence of James Loveless, in sec. 34, T. 1 S., R. 7 W., 

 and found it to be a blue-black silt, very calcareous, and containing only 

 minute pebbles and sand grains. Several specimens of wood from this silt 

 which were inspected by the writer also carried a coating of similar silts. 

 Above the silt there is ordinary till, except a thin coating of loess at the 

 surface and pockets or thin beds of sand or gravel or silty clay in the till. 

 In Mr. Loveless's well the following- section appears: 



Section in well of James Loveless, between Liberty and Fowler, Adams County, Illinois. 



Feet. 



Yellow silt or loess 6 



Ashy soil and subsoil containing a few small pebbles 12 



Calcareous yellow till 22 



Gray gummy clay, resembling soil, noncalcareous 2 



Calcareous yellow till 18 



Blue-black silt, very calcareous 2 



Total depth 62 



At the county infirmary, in sec. 11 of the same township (T. 1 S., 

 R. 7 W.), a well struck rock at a depth of 165 feet. The lower 100 feet of 

 the drift is a blue silt apparently similar to that in Mr. Loveless's well. A 

 shallower well at the infirmary obtained water in sand and gravel at a 

 depth of 40 to 58 feet. A well on the farm of Mr. Henry, in sec. 3, within 

 a mile of the infirmary, has a section similar to that of the deep infirmary 

 well and entered rock at 160 feet. 



Several of the wells in the village of Liberty penetrate a similar blue- 

 black silt, entering it at about 60 feet and continuing in one case to a depth 

 of 90 feet without entering rock. In the vicinity of this village, however, 

 rock is occasionally entered at a depth of 50 feet or less, and only 2 miles 

 east of the village and at a slightly 'higher elevation rock is struck at only 

 25 feet. 



There is a low ridge leading from the village of Coatsburg eastward 5 

 or 6 miles on which the wells occasionally enter a blue-black silt similar to 

 that found on the district just described. A well at the mill in Coatsburg is 

 reported to be mainly through pebbly clay to a depth of 65 feet, beneath 

 which there is a blue clay with sand joartings and wood embedded, which 

 was penetrated 30 feet without entering rock. A boring for coal a mile east 

 of Coatsburg is discussed in the Ceology of Illinois because of the occur- 

 rence of this blue-black material in the lower portion of the drift, which is 



