542 



IOWA ACADEMY OF SCIENCE Vol. XXV, 1918 



SECTION OF A GULLY WALL, FERTILE TOW^NSrilP, WORTH 



COUNTY. 



The west wall of the gully shows a dense, bluish black jointed clay, 

 (1) of figures 172, beneath Wisconsin; the clay is highly jointed, the 

 uijper portion showing rather marked contortion; no bowlders are 

 present, but numerous small pieces of quartz are visible. The material 

 marked (2), in figure 172, is fine sand with highly distorted laminae. 



A section of the west bank of the north-south ffuHy, is shown 

 in fionre 173. 



Fig. 173 



SECTION OF A GULLY WALL IN FERTILE TOWNSHIP, 

 WORTH COUNTY. 



Feiet 



A. Soil filled with roots IY2 



B. A grayish clay, highly calcareous, showing distortion, (Wis- 

 consin drift) 2 



C. Dense bluish black, jointed clay, calcareous, the upper part 

 showing contortion, and containing fossil shells and pieces 

 of petrified wood. Exposed to the base of the gully 15 



D. Large sand inclusion, 8 feet wide, and extending from imme- 

 diately beneath the Wisconsin drift to the bottom of tlie gully: 

 sand laminated and highly distorted and having the edges of 

 the laminse iron stained. 



!<:. Pebbles and gravel along contact of the sand with the Kansan 

 drift; the pebbles range in size from one-half inch to two 

 inches in diameter and are cemented together by iron oxide. 



The age of the drift liere l)eneath the "Wisconsin is Kansan. 

 To the sontli of the sand pocket the joints of t'le Kansan drit\ 

 in the upper portion, instead of being vertical, dip to the south 

 and show .some distortion which suggests strongly shearing 

 planes resulting from the pressure of the overriding Wisconsin 

 ice. To the north end of this same exposure, figure 173, Wiseon- 



