BULL. GEOL. SOC. AM. 



VOL. 23, 1911, PL. 41 



Figure 1.— Section at East Des Moixes High School 

 a. Yellow loess; &. Gray loess mingled wiTli Wisconsin pebbles; c. Wisconsin drift 



Fhuke 2. — Section at Sioux Falls 



o. Cxi-ay silt witli brolcon shells; h. Kun.san drift 



SECTIONS SHOWING MINGLING OF PLEISTOCENE FORMATIONS 



•-■^ 



