128 B. SHIMEK AFTONIAN FOSSILIFEROUS GRAVEL AND SAND BEDS 



3. Anderson section. — This is in a sand pit located in the southeast 

 quarter of the northwest quarter of section 13, township 89 north, range 

 xlviii west, north of North Eiverside, Sioux City, Iowa. 



The section shows the following members : 



Loess, 8 to 12 feet. 



The Lovelaiid, an irregular mass of reddish joint clay. 

 Kansan typical bluish till, 6 to 8 feet. 



Fine laminated bluish or yellowish silt, evidently Aftonian, 5 to 8 feet. 

 Aftonian sand, cross-bedded with streaks of MnOa and iron, and con- 

 taining mammalian fossils, 22 to 30 feet. 



Mr. Anderson reports larger boulders and gravel under the sand resting 

 on rock. 



The following fossils were collected in the Aftonian sand and gravel : 



174. Megalonyx — — , ungual phalanx. 



175. Megalonyx (?) , patella. 



176. A canine tooth, not identified. 

 178-181. Equus complicatiis, various teeth. 



Various fragnyents of bones and teeth, not identified. 



4. N'eiv Woodward section. — This is a new sand pit located in the 

 southwest quarter of section 9, township 85 north, range xliv west, about 

 2 miles southwest of Eodne}^, Iowa. ' This exposure shows about 3 feet of 

 fine, white, cross-bedded sand containing shells of mollusks, and above it 

 an irregular mass of sand and gravel about 8 feet deep. 



^ The material l3dng above the sand is not clearly defined, on account of 

 slumping, but it is mixed drift and gravel, such as is common in this 

 region, where the Kansan plowed into the upper part of the Aftonian. 



The sand contains silt balls or pellets, such as are common in the 

 Aftonian, and in all respects the structure and composition of the beds 

 are typical. Moreover, several sections in the vicinity show the unmis- 

 takable presence of the Aftonian— one, located in Woodwards Glen, in the 

 southwest quarter of section 17, showing a distinct layer of Nebraskan 

 drift^^ immediately below the Aftonian. 



The following mollusks were collected in the white sand in section (4) : 



Pisidium - — -. 



Sphcerium , probably S. sulcatum, fragments. 



Lymnwa , probably L. humilis, broken. 



" The pre-Kansan, or sub- Aftonian drift, was named Nehi'askan in Science, n. s., vol. 

 xxxi, pp. 75-76, January 14, 1910. The name also appears in the Bulletin of the Geo- 

 logical Society of America, vol. 20, p. 408. dated December, 1909, but not distributed 

 until after the publication in Science. 



