

240 LIFE OF THE PLEISTOCENE 



In the vicinity of Rock Island several exposures referable (apparently) to 

 the Aftonian occur, 91 and a well section is given by Leverett which is repro- 

 duced below: 



8. Yellow till (probably Illinoian) 5 feet 



7. Black muck (Yarmouth?) 1 



6. Brown till (leached 2 or 3 feet) 7 



5. Blue till (probably Kansan) 4 



4. Black calcareous silt, with gastropod fossils 8 



3. Black muck 5 



2. Green muck with a few local pebbles 5 



1. Coal measure shale x 



Height of section 34 " 



The gastropod shells in No. 4 were identified as follows: 



Helicina occulta Pyramidula cronkhitei anthonyi 



Pupa allicola Succinea avara 



Similar deposits occur in the b'uffs east of Cordova, Illinois, and Clinton, 

 Iowa. 



How far eastward the Aftonian biota may have extended is not at present 

 definitely known. Like the fauna and fiota of the Pliocene, it was probably 

 widely distributed in all directions. Several deposits outside of the southern 

 limits of the ice sheets may possibly be correlated with this stage, as for example 

 the Hay Springs, Nebraska, fauna, and the Christmas Lake, Oregon, fauna. 



10. Canada 



No deposits of unquestionable Aftonian age are known from Canada. 

 Coleman 62 in a late paper refers the Toronto Interglacial deposits to the Afton- 

 ian interval. The fauna of these deposits seems more like that of the Yar- 

 mouth or Sangamon, especially the mammals. The deposits have usually 

 been classed as post-Illinoian (Sangamon) and they are so considered in this 

 paper. More conclusive data seem necessary to correlate these deposits with 

 the Aftonian. 



A new species of plant {Ficus) found in interglacial deposits of the Kootenay 

 Valley, 93 British Columbia, may belong to the Aftonian interval, as well as the 

 Montana deposits described by Alden and mentioned on a previous page of 

 this work. No age is given by Hollick. It is also possible that they may 

 be of Yarmouth age and post-Kansan. 



61 Leverett, lion. XXXVIII, p. 114; Udden, Proc. Iowa Acad. Sci., V, p. 103. 

 92 Bull. Geol. Soc. Amer., XXVI, pp. 243-254, 1915. 

 63 Hollick, Bull. Geol. Soc. Amer., XXVI, p. 159, 1915. 



