PBE-WISCONSIN drift and associated deposits. 

 Stride outside of the Wisconsin drift in Indiana. 



73 



PUTNAM COUNTY. 



Sec. 25, T. 13 N., E. 4 W : 



Sec. 22, T. 13 N., It. 4 W 



Sec. 28, T. 13 N., R. 4 W 



Near Cloverdale 



OWEN COUNTY. 



Near Romona 



Sec. 32, T. UN., R. 3 W 



3 miles south-southwest of Yandalia 



5 miles west from the preceding 



Sec. 20, T. 9 N., R. 5 W 



CLAY COUNTY. 



Sec. 6, T. 11 N., R. 5 W 



3 miles south-southwest of Bowlmi,' Green 



Sec. 1,T.11N,E.6W 



Do 



Sec. 19, T. 11 N., R. 5 W 



VIGO COUNTY. 



Sec. 3, T. 10 N., R. 9W 



Sec. 36, T. ION., R. 9 W 



SULLTVAN COUNTY 



2 miles southeast of Farmersburg 



GREENE COUNTY. 



1 mile northeast of Worthington 



Sec. 6, T. 1 N., R. 4 W 



S.4°E 



S.5°E 



N.-S 



S. 3° 40' E.o. 



S. 18° E 



S. 22° E 



W.-E 



S. 40°-50° E. 

 S. 1S°-46°E. 



S. 26°30'E. 

 S. 32° 10' E. 

 S. 36°56'E. 



S.34°E 



|S. 26° 30' E . 

 |S. 30°35'E. 



S. 20° W.._. 

 N.-S 



N.-S 



S. 72° E 



Siebenthal. 



Leverett. 



Wright. 



SANGAMON SOIL AND WEATHERED ZONE. 



The Sangamon soil and weathered zone, formed on the surface of the Illinoian drift, has 

 received attention in Monographs XXXVIII and XLI of this Survey, and little need be added 

 concerning it. It separates the Ilhnoian drift by a very marked interval from the overlying 

 loess and associated silt deposits. The writer has never observed the Ilhnoian drift to grade 

 upward into the loess, either in Indiana or in the neighboring States, but has everywhere found 

 it to be capped either with a deeply weathered zone or with a dark-colored soil. 



These observations, however, are not in harmony with statements of several other geolo- 

 gists, who report gradations of the earlier or Ilhnoian drift into the overlying loess. The writer 

 is of the opinion that these statements by his fellow workers are based on defective observa- 

 tions, for in two places occurrences claimed by two of his colleagues to illustrate such a transition 

 were proved by a little excavating to afford good examples of an interval between the till and 

 the loess, the surface of the till, being deeply weather-stained. In these cases the talus had 

 been taken to be material hi place. Where loess has crept down a slope over an eroded till surface 

 from which the weathered zone had been removed, the inference might readily be drawn that 

 no marked interval had occurred. 



The interval between the Illinoian drift and the loess is generally marked in Indiana by 

 a dark-brown coloration and by disintegration or weathering of the upper part of the till sheet. 

 The deep brown changes gradually below to the ordinary brownish-yellow color of oxidized 

 till and then to the unoxidized blue or gray tiU, but at the top it terrnina-tes abruptly at the 

 base of the much fresher looking overlying silt. The dark-brown color extends usually to a 

 depth of only 1£ to 3 feet, but leaching and some discoloration by weathering is generally 

 noticeable to a depth of 6 to 8 feet. Where the surface of the Illinoian drift was flat or poorly 

 drained prior to the loess or silt deposition, a black gummy soil is found, which contrasts 

 sharply in color with the overlying yellowish-brown loess or the pale white clay or silt. The 

 black soil has been seen frequently in all parts of the Illinoian drift outside the Wisconsin or 

 newer drift from central Ohio to southeastern Iowa and occasionally inside the limits of the 

 newer drift. The dark-brown weathered till surface is to be seen in nearly every newly 

 made exposure in the well-drained districts. As the general thickness of the overlying silt in 



