TITLES AM) AHSTHACTS UK rAl'KKS 13:^ 



vtM-y loiii; intt'ri:ljn-i:il onocli. At s«»vt»r:il places luMr tho villai;^ of Alton 

 and also west of Osceola, about 20 miles east of Aftoii, there are fine out- 

 crops of Nebraskan gunil)otil, below which is Nebraskan drift and above 

 which is Kansan drift. Moreover, in Dodge township, Union County, there 

 is a splendid section of peat lying on Nebraskan drift and overlain by Kansan 

 drift. This peat beil was describe<l years ago by iSavage. The gunibotil and 

 the i)eat are now the significant evidence of Aftonian time. 



If the interpretations, of the writer are correct, the Aftonian gravels of 

 Union County have lost much of their former significance, and the type sec 

 tions. particularly the Grand River section, can no longer be referred to as 

 sei'tions in which it is possible to study the two oldest *lrift-sheets separated 

 by Aftonian gravels. 



Presented without noto^5, with hxnteni-slide illustratiDiis. 

 The session adjourned about 5.30 o'clock p. ni. 



Sectional Sessions 



Two additional sections were formed Tuesday afternoon for the read- 

 ing of papers. The first was presided over by former President A. P. 

 Coleman, with D. F. Hewett acting as secretary. 



Tlie following papers were presented : 



WISDROW FORMATIOX, AX UPLAXD GRAVEL FORilATIOX OF THE DRIFTLESS 

 AXD ADJACENT AREAS OF THE UPPER MISSISSIPPI VALLEY 



BY F. T. THWAITES AND W. II. TWENHOFEL 



( Abstract) 



TIm' Wiiidi-ow formation consists of widely separated patches of quartz and 

 chert gravels, with associated limonite deiK)sits. which o(<'ur on the tops of 

 high elevations, throughout the driftless area of the ui)pcr Mississippi Valley 

 and the adjacent glaciated area to the west and south. The chert pebbles con- 

 tain fossils, of which the youngest are certainly of Silurian age. The authors 

 have conclude<l that this formation was river-depositcil at a riinc tar ante 

 dating the Pleistocene and not necessarily connected with prticpla nation, and 

 that no definite age can be assigned. 



Pre.sented without nianuscrij)t by W. H. 'I'wt'iibotcl. 



roRREr.ATioy or the cesozokj formatiows' or the great basis 



BY JOHN r. MFRRIAM 



Presented by title by request of the author. 



