CA RB ONIFER O US A ND PERM J A X FORMA TIOXS 5 



Cotto/nvood formation.— The most eastern outcrop of the Cot- 

 tonwood limestone seen in Nemaha county is the one which is 

 known as the Van Court or Keyes quarry and is three and three- 

 fourth miles directly west of Auburn. Unfortunately my barom- 

 eter at the time of my visit was not reading accurately ; but its 

 altitude is estimated as some 345 feet above the Missouri River. 

 The Cottonwood limestone forms a massive light gray stratum 

 four feet thick, moderately hard and filled with large numbers 

 of Fiisidina. When freshly broken the Fiisulinas though 

 slightly darker in color than the limestone are less prominent 

 than on the weathered surface and are only conspicuous when 

 seen through a magnifying glass. On the weathered surface of 

 the rock the shells resist decay longer than the limestone and 

 stand out prominently. One who has visited the large quarries 

 of Cottonwood limestone in northern and central Kansas would 

 be immediately impressed with this very striking similarity. 

 Few, if any, "fossils other than FusuH?ia cylindrica Fischer 

 occur in this^ limestone ; only an occasional fragment of a spine 

 of ArchcBocidaris or a bit of shell was noticed. The section at 

 the Keyes quarry is as follows : 



Kt. In. Ft. In. 



3. Shaly limestone containing Athyris {Scininula) subtiUta (Hall) 



Newb. and a few other fossils - - - - ' - i = Q 



2. Light gray shales to shaly limestone - - - i 9 = 5 9 



I . Cottoniuood limestone, light gray massive Fusulina limestone 4 = 4 



The Nemaha county quarry which is the most extensively 

 worked is the next well-exposed section of the Cottonwood 

 limestone and is one and one-fourth miles west of the Keyes 

 quarry. It is located by the side of the Burlington and Mis- 

 souri River Railroad, f^ve miles due west of Auburn and one mile 

 north of Hickory Grove. The average of three barometric 

 readings makes the bottom of the quarry 130 feet higher than 

 Auburn or approximately 365 feet above the Missouri River. 

 This is twenty feet higher than the base of the Keyes quarry 

 which gives a dip directly east of twenty feet in one and one- 

 fourth miles or at the rate of sixteen feet per mile. The follow- 



