82 IOWA ACADEMY OF SCIENCES. 



sheets in the region of overlap between Davenport, Iowa and 

 Quincy, 111. The presence of this soil horizon was first brought 

 to the writer's notice by a well section at Yarmouth in Des 

 Moines county, Iowa. For this reason, and because the name 

 of this village is less likely to be confusing than names which 

 are common, it seems appropriate to apply the name Yarmouth 

 to this weathered zone. There is also at Yarmouth not only a 

 soil horizon but apparently a pronounced erosion between the 

 Illinoian and Kansan sheets. g 



( ]"W~W'y^^ THE YARMOUTH SECTIONS. 



""^bout ten years ago Mr. William Stelter of Yarmouth, Iowa, 

 sunk a well near that village which passed through a bed of 

 peat at the base of the Illinoian till sheet. The peat con- 

 tained small bones which have been identified by Dr. F. W. 

 True, of the United States National museum, as: (1) a portion 

 of the pelvis and upper part of the femur of the wood rabbit 

 {Lepus sylvaticus); and (2) the -scapula of the common skunk 

 {Mephiticus mephitica). The following section was furnished 

 by Mr. Stelter soon after the well was dug, and specimens of 

 the several classes of material penetrated were also furnished 

 me for examination: 



FEBT. 



Soil and loess loam 4 



Yellow till (Illinoian) 20 



Gray till (Illinoian) 10 



Peat bed with twigs and bones 15 



Gray or ashy clay containing- fragments of wood. . 12 



Fine sand 16 



Yellow sandy clay with few pebbles (Kansan) 33 



Total depth 110 



One mile south of Yarmouth, on the farm of Mr. F. Smith, a 

 well was in process of excavation during a visit made by the 

 writer to that region some years later, and the following section 

 was determined by examination of the material in the dump, 

 and by explanations by the well borer. The well is located on 

 a high point of the ridge marking the border of the Illinoian 

 drift, perhaps twenty-five feet higher than the village of Yar- 

 mouth, which also stands on the ridge. It will be observed 

 that the black muck penetrated in this well is at a level fully 

 forty feet lower than in the well at Mr. Stelter 's. This differ- 

 ence in level is interpreted to be due to one well having 



