138 B. SHIMEK ^AFTONIAN FOSSILIFEKOUS GRAVEL AND SAND BEDS 



Loess, heavier, yellow with bluish mottliugs and ferruginous lines 

 and cloudings, such as appear commonly in older loess, fossil- 

 iferous, 5 to 6 feet. 



Aftonian sand and fine gravel, 35 feet. 



N'o drift appears in the section, but the lower loess has the appearance 

 of some of the yellower post-Kansan or oldest post-Iowan loess. It is evi- 

 dently older than the Wisconsin, which might have also left gravel trains 

 in the valley of the Boyer, as that stream drains Wisconsin border ter- 

 ritory. 



The dune sand layer may correspond to similar formations which are 

 common along the border of the lowan drift and which were evidently 

 formed in immediately post-Iowan time. The structure of these sands 

 and gravels, their position under an old loess, and their fossils seem to 

 warrant their reference to the Aftonian. 



The following fossils were obtained from this part of the pit : 



21. Elephas p7imigenius, molar (see ibid., plate 23, figure 2). 

 28, 29. Eleplias (?), tusks, 2 pieces. 



Cervalces , part of antler. 



Sphwrhim, probably 8. sulcatum, fragments. 



•30. Offerman pit. — This sand and gravel pit is located in the Missouri 

 River bluffs in South Omaha, Nebraska. Here the Aftonian beds are 

 typical, and in the western part of the pit the underlying Nebraskan drift 

 is distinct. The workmen have penetrated into the latter about 16 feet. 



Above the Aftonian there are about 8 feet of Loveland and 8 to 12 feet 

 of loess. 



In the southeastern part of the pit, which is the only fossiliferous part, 

 8 to 15 feet of Aftonian sand and gravel are exposed, and above these is a 

 very prominent layer of Loveland 30 feet thick. 



At other points in these bluffs Kansan till is very distinct between the 

 Loveland and the Aftonian. 



The following fossils were obtained from the Aftonian : 



Elephas imperator, part of molar. 

 Equus -, fragment of molar. 



21. Gladivin section. — This is located in the east half of section 35, 



township 71 north, range xliii west, and its position has been described by 

 ralvin.18 



Here, in a bed of Aftonian silt, a complete set of upper and lower left 



w Bull. Geological Society of America, volume 20, p, 344. 



