I 7 8 ERA NK LE VERE TT 



six feet or more. Where it is absent the leaching generally 

 extends to a depth of six feet below the base of the loess. The 

 variations in depth of leaching appear to depend on the con- 

 ditions for percolation of water, being greatest where percola- 

 tion is most rapid. 



Noteworthy exposures of Sa?iga.7non soil. — A few instances of 

 the exposures of this soil are selected which will illustrate the 

 variability in its character. The first section, at Ashland, 111., is 

 near the place where Professor Worthen reported its occurrence. 



The following series of drift beds were penetrated by a coal 

 shaft at Ashland, the identifications being made by the writer 

 from samples of the material preserved at the engine house : 



Feet 

 Soil, - - - - 1% 



Yellow loess, fossiliferous, ------ g 



Blue loess, ........ 2 



Peat with black, sandy slush, - - - - - 22 



Bluish, gummy clay with few pebbles, - - - 20 



Yellow till, --------- 30 



Total drift, - - - 84 K 



At the air shaft sand was found in the place of the blue 

 gummy clay beneath the peaty slush. A similar thick bed of 

 peat has been noted at several other points in that region, one 

 of the most conspicuous being in a well at Virginia City made 

 by Mr. Oldridge. The peat was entered at the base of the loess 

 at about 15 feet and continued to a depth of 28 feet, beneath 

 which a blue gummy clay was found. The drift at Virginia City 

 has a depth of 187 feet, as shown by the coal shaft. This shaft 

 is reported to have passed through a lower black soil between 

 till sheets at 67 to 70 feet. 



In the south part of the Sangamon basin, in the vicinity of 

 Taylorville, 111., the loess which has a thickness of 10 to 15 feet 

 is underlaid by beds of sand and gravel, carrying thin peat beds 

 in their midst as well as at the junction of the loess and the 

 sand. At the Taylorville coal shaft the uppermost peat bed was 

 found at 13 to 15 feet, and the lowest at 40 to 44 feet. Numer- 



