712 CHARLES S. PROSSER 



shales, on account of the excellent outcrops of both in the 

 bluffs bordering the Cottonwood River below and above Cotton- 

 wood Falls and Strong. The lower division was named the 

 "Cottonwood limestone" and the upper the "Cottonwood 

 shales," 1 while the same limestone quarried in the vicinity of 

 Alma was mentioned locally as the "Alma massive limestone." 2 

 The following year the formation and its two members were 

 more fully described by Prosser. 3 The name "Cottonwood," 

 however, was apparently used for a geological division by N. F. 

 Drake as early as September, 1893, when he described the 

 "Cottonwood Creek bed" of the Texas Carboniferous. 4 It is 

 now proposed to limit the formation to the Cottonwood lime- 

 stone and on account of the prior use of the name Cottonwood 

 for the Texan bed, to call it the Alma limestone from the out- 

 crops near the town of that name in Wabaunsee county, while 

 the Cottonwood shales are referred to the succeeding formation. 



Garrison formation. — This formation is composed of two mem- 

 bers, the yellowish fossiliferous shales at the base, formerly 

 called the Cottonwood shales, and the upper one, composed of 

 the alternating gray limestones and various colored shales called 

 the Neosho, with a total thickness of from 140 to 145 feet. 

 The lower shales have a thickness of thirteen feet near Strong, 

 but decrease to two or three feet in the northern part of the 

 state. The lower part of these shales contains immense num- 

 bers of a few species of fossils and on this account may be 

 readily identified wherever outcrops occur. Since the geographic 

 name "Cottonwood" is preoccupied the term "Cottonwood 

 shale " is abandoned, and they are renamed the Florena shales 

 from the exposures over the Alma limestone in the quarries 

 near Floren, in the Big Blue valley. 



The upper member of the formation is composed of green, 

 chocolate, and yellowish shales alternating with grayish lime- 

 stones, while in the Big Blue valley a bed of gypsum occurs near 

 the base. Certain layers of the coarser shales and limestones 



1 Bull. Geol. Soc. Amer., Vol. VI, Nov. 1894, p. 40. ''Ibid., p. 44. 



3 Jour. Geol., Vol. Ill, Oct. 1895, pp. 697-705. 



4 Fourth Ann. Rept. Geol. Surv. Texas, pp. 374, 382. 



