THE ILLINOIAN ICE INVASION 309 



These deposits include two loesses, an upper light yellow loess, and a lower, 

 darker loess. The first is post-Iowan (Peorian) while the second is post- 

 Illinoian (Sangamon). Shimek 109 refers the lower loess to the post-Kansan 

 interval, but as it lies on the Illinoian drift it is later than the post-Kansan in- 

 terval (Yarmouth), and must be considered as of Sangamon age. The lower 

 loess is exceedingly fossiliferous, the upper much less so, in fact, containing 

 but few examples. On the Kentucky side of the River, near Henderson, the 

 marl-loess contains several species of helices, Bifidaria armifera, Succinea, and 

 Pomatiopsis {Cyclostoma)} 10 



Deposits of mussel shells have been exposed in the bank of the Ohio River 

 near Florence, Switzerland County. These are from 3 to 10 feet below the 

 surface. The shell beds are said to have been deposited by Man, but this 

 statement it would seem, is open to grave question. They are probably natural 

 deposits, belonging to the Sangamon or to a later period. 111 In the river bank 

 opposite Florence the shell bed is 32 inches beneath the surface. Other de- 

 posits also occur. 112 



c. Mammalian Fauna 



Mammals referable to Sangamon age are present in Indiana deposits. 

 Mastodon remains were exhumed some years ago at Wm. Cordery's sand bank, 

 300 feet west of the Madison and Indianapolis Railroad, 12 feet below the sur- 

 face, in a sand and gravel deposit. 113 In Martin County both the mastodon 

 and the mammoth are reported from marsh clay, resting on drift. 114 In Dear- 

 born, Ohio, and Switzerland counties, in various deposits overlying Illinoian 

 drift, the remains of the mammoth and the mastodon have been observed. 

 Many of these deposits are in the river bank. Mastodon remains have been 

 recorded from various deposits, many of which are probably referable to the 

 Sangamon interval. These are listed below: 



Clarke County; near Charleston Landing, Ohio River, above Louisville, 

 Ky., in sand bank. 115 



Dearborn County; five miles west southwest from Aurora, on blue clay, 

 8-9 feet below the surface. 116 



DuBois County; near mouth of Wolf Creek, at "Rock House," ford of the 

 White River. 117 East branch of White River. 118 



109 Journ. Geol., XIII, No. 3, p. 232. 



110 Leidy, Smith. Contr. Knowl., VII, Art. V, pp. 7-8. 



111 Geol. Surv. Ind., 3rd and 4th An. Rep., pp. 408-409. 

 n " Op. cit., p. 414. 



113 Borden, Geol. Surv. Ind., 6th An. Rep., p. 141. 



114 Cox, op. cit., 2nd An. Rep., p. 103. 



115 Borden, Geol. Surv. Ind., 5th An. Rep., p. 176; Hay, 36th An. Rep., p. 700. 

 118 Hay, op. cit., p. 701. 



117 Collett, op. cit., 4th An. Rep., p. 214. 

 1,9 Hay, 36th An. Rep., p. 703. 



