42 THE ILLINOIS GLACIAL LOBE. 



Yarmouth is situated about 20 miles northwest of Burlington, the county 

 seat of Des Moines County, on the line of the Burlington and Western 

 Railway. It stands on the ridge which marks the western border of the 

 Illinoian till sheet. The well above referred to, which first suggested to 

 the writer the occurrence of two distinct sheets of till in southeastern Iowa, 

 was made by William Stelter, on the border of the village of Yarmouth. 

 The writer visited the well soon after it was bored and made out the follow- 

 ing section from the material exposed in the dump : 



Section from well of William Stelter, near Yarmouth, Des Moines County, Iowa. 



Feet. 



Soil and loam (Iowau loesa) 4 



Brownish yellow till (Illinoian) 20 



Gray till (Illinoian) 10 



Peat bed with twigs and bones (Yarmouth) 15 



Gray or ashy sandy clay, containing wood (Yarmouth) 12 



Fine sand (Yarmouth) 16 



Yellow sandy till with few pebbles (Kansan) 33 



Total depth 110 



The bones found in the peat were sent to the Smithsonian Institution 

 and there identified bv Dr. F. W. True, as follows: 



(1) A portion of the pelvis and the upper part of the femur of the 

 wood rabbit (Lepus sylvaticus): (2) the scapula of the common skunk 

 (MepMticus mephiticd). The occurrence of these bones was first announced 

 by McGee, in the Eleventh Annual Report of this Survey, and referred to 

 a "forest bed," but without more definite reference. 1 



The thickness of the peat in this well and of the associated sandy clay 

 charged with wood, is an impressive evidence of an interglacial interval of 

 considerable length. But in the writer's opinion it furnishes less weighty 

 evidence than is afforded by the general weathering which took place on 

 the surface of the Kansan sheet prior to the deposition of the Illinoian drift. 

 The peat naturally arrests attention quicker than the reddened zone, but is 

 more restricted in its development; yet several instances of the occurrence 

 of beds such as the one at Yarmouth have been brought to the writer's 

 notice. They appear to be rather more prevalent along the extreme border 

 of the Illinoian than at points some miles back beneath it ; but instances 

 occur all over the portion of southeastern Iowa invaded by the Illinois lobe. 



1 See p. 495 of report cited, published in 1891. 



