ABSTRACTS OF PAPERS PRESENTED 113 



viduals and in vertical range, extending from the Intermediate limestone of 

 the Devonian, through the great thicknesses of the Banff limestones and shales, 

 to the Rocky Mountain quartzite of the Pennsylvanian. A brief discussion of 

 these species will be given, with some notes on their evolution from lower to 

 higher beds. 



The next paper was read from manuscript and illustrated with charts ; 

 20 minutes: Discussed by K. S. Bassler. 



CONTRIBUTIONS TO THE BLACK SHALE PROBLEM 

 BY CHARLES BUTTS 



(Abstract) 



The Chattanooga (black) shale is 20 to 40 feet thick at Chattanooga. It 

 thins southward, and at Birmingham, Alabama, is only 2 or 3 feet thick. 

 Northward the black shale thickens to 500 feet at Cumberland Gap and ap- 

 parently 1,500 feet at Big Stone Gap, Virginia. Thirty miles northeast of 

 Big Stone Gap, at Dump Creek, Virginia, is an upper black shale 25 feet thick 

 and a lower 200 to 300 feet, with bottom not exposed, and between the two is 

 1,500 feet of green shale and thin sandstone, which is clearly Chemung and 

 Portage. On the west escarpment of Pine Mountain, in eastern Kentucky, 

 the black shale is 800 feet thick and bottom not exposed, with no Chemung 

 and Portage. 



The black shale has always been regarded as Devonian until that identifi- 

 cation was challenged in recent years by E. O. Ulrich. In this paper it is 

 shown that the lower shale of the Dump Creek section and the lower part of 

 the black shale mass at Big Stone Gap and at least the lower 300 feet at 

 Cumberland Gap is Devonian and probably represents the Genesee shale, while 

 the upper black shale in the Dump Creek section may be Mississippian, and 

 that this bed may be represented by the upper 200 to 300 feet of the black 

 shale at Big Stone Gap, etcetera, the Chemung and Portage separating the 

 two black shales at Dump Creek having thinned out. South of Cumberland 

 Gap the Devonian part of the black shale may lap out and only the upper, 

 possibly Mississippian, part persist as the Chattanooga shale. 



The next paper was presented from notes by the author; 15 minutes. 



NOTES ON THE EOCENE OF THE BIG HORN BAS1\ OF \\)<>\ll\<; 

 BY W. K. GRANGER 



The two following papers were read by title: 



NEBRASh l WURYPTBR1DB 

 BY E. H. BARBOUR 



PLANT TISSUE IN THE CARBONIFEROUS 8HALBB <>r NEBRASKA 



BY E. H. BARBOUR 

 Vin— Bull. Geol. Soc. Am.. Vol 24, L912 



