264 LIFE OF THE PLEISTOCENE 



4. Sand and pebbles, with some boulders at base (Wisconsin) 8 feet 



5. Sand with fresh water shells (Peorian) J^foot 



6. Sand and gravel (Iowan) 6 feet 



7. Sand with fresh water shells (Yarmouth) 8 inches 



8. Soil and subsoil (Yarmouth) 6 feet 



Height of section 38 ft. 2 in. 



From bed No. 7, ten species of mollusks were secured. 



Valvata tricarinata Lymnaea columella 



Amnicola limosa Pyramidula cronkhitei anthonyi 



Planorbis antrosus (=bicarinatus) ( = striatella) 



" panus " alter nata 



Ancylus species Zonitoides arborea 



Sphaerium species ( = Cyclas) 



Shells and trees are reported beneath two distinct beds of till in Blue Earth 

 County; 72 the upper, till is Wisconsin and the lower is probably Iowan, the 

 life being referable, therefore, to the Yarmouth interval. In Clay County, 

 at Barnesville, a well boring exhibited the following strata: 



Oxidized surface of till 2 feet 



Yellowish till 10 " 



Thin quicksand 1 " 



Depth of well 13 feet 



The quicksand contained branches and trunks of trees thot to be tamarack. 

 The specimens were lying across the well, and many of them measured eight 

 inches in diameter. The till beneath the Wisconsin at this locality is probably 

 Kansan and the quicksand would therefore be referable to the Yarmouth 

 interval. 



In McLeod County 73 the Yarmouth is apparently represented in several 

 well borings. One such, four and one-half miles east of Hutchinson Village, 

 showed: 



Yellow upper till 14 feet 



Harder gray till 3 " 



Dark bluish till 13 " 



Gray sand 2 " 



Depth of well 32 feet 



The upper yellow till is Wisconsin as is the harder gray till. The dark 

 bluish till is Iowan. The sand beneath, here referred to the Yarmouth inter- 

 val, contained an abundance of gastropod shells. 



" Geol. Minn., Final Rep., 1, p. 441. 

 n Op. til., 11, pp. 186-187. 



