[Annals N. Y. Academy of Sciences, Vol. XX, No. 5, Part II, pp. 243-294, 



Pll. XIV-XV. 20 Decembek, 1910] 



THE COAL BASIN OF DECAZEVILLE, FEANCE 



By John J. Stevenson 

 {Read in abstract before the Academy, 7 November, 1910) 



CONTENTS 



Page 

 Introductory notes 243 



Rocks surrounding the basin 245 



Description of the basin 247 



The Auzits system 250 



The Campagnac system 252 



The Bourran system 261 



Character of the coal 271 



Original extent and character of the basin 273 



Mode in which the basin was filled 276 



Extent of the coal beds 279 



Origin of the coal beds 281 



History of the Decazeville coal basin 291 



INTRODUCTORY NOTES 



The Decazeville coal basin, named from the chief city within its borders, 

 is in the department of Aveyron, about 400 miles south from Paris and 

 about 190 miles south from Commentry. The mines, originally opened 

 for the Due de Decazes, have been in operation for more than a century. 

 The properties are controlled by two great organizations, the Compagnie 

 anonyme de Commentry, Fourchamboult et Decazeville, with important 

 steel works at Decazeville, and the Compagnie des Mines de Campagnac at 

 Cransac, five miles farther south. Within a short distance from the latter 

 city, is the widely extended area of exploitation by the Societe des Acieries 

 de France, from which the greater part of the coal has been removed. 



The basin is rudely triangular in form; the longer axis, from west of 

 north to east of south, is about 12 miles long, and the width varies from 

 nearly six miles at the south to barely one third of a mile at the north, 

 where the coal rocks pass under deposits of early Tertiary age. The total 

 area of Coal Measures is not far from 30 square miles, so that it is about 

 ■^ve sixths as large as a township in Ohio. The interest attaching to the 



(243) 



