353 



ALUM MINES OF AUBIN. 



Alum mines 

 of Aiibin. 



from coal-pits 

 that have 

 taken fire. 



Description of 

 the coal 

 country. 



Its structure. 



VII. 



On the ,Alum Mines of Aubin in the Department of the 

 Aveyron; by Mr, L. Cordier, Engineer in chiefs <^c. * 



T 



1. HE alum mines of the country of Aubin differ from 

 those of the same nature worked in other places: their 

 existence is wholly contingent. The periods of their for- 

 mation are known, and are very recent. They occupy no 

 considerable space of ground, and cannot extend much 

 farther. Lastly their duration must be very limited, 

 whether they be worked or not. These mines are nothing 

 but coalpits, that have taken fire within a certain distance 

 of time, and in which the fire is still daily exercising its ra- 

 vages. There are four of them; those of Lassale, Fon- 

 taines, Budgne, and Bourlhones. To give an idea of their 

 situation, that of the coal in the country must be known. 



The territory of Aubin is very hilly, and intersected by 

 deep narrow passes. The part to the north-east of the 

 town consists entirely of coal country, and is the least 

 elevated, being nearly in the form of an elliptic basin, the 

 great axis of which is north and south, and the surface of 

 which exceeds a square myriametre [24676 acres]. This 

 space is skirted and overtopped on all sides by the primitive 

 soil; and is occupied by a pretty considerable number of 

 oblong hills, intersected in every direction, and crowded 

 together. The highest, for they are unequal in this respect, 

 are two or three hundred metres above the valleys. 



The arrangement of the strata throughout the basin ex- 

 hibits nothing constant, or continued. Independent of the 

 interruptions occasioned by the narrow passes and valleys, 

 the direction, inclinafion, and order of the strata vary 

 from one hill to another; so that to depict the present 

 state of the soil, it is sufficient to say, that it appears to be 

 the result of a complete disruption. We can merely per- 

 ceive, that the directions more frequently approach the me- 

 ridian than any other line, and that the prolongation of the 



•Abridged from the Journal des Mines, vol. xxvi, p. 401. 

 From the Report made to the council of Mines in 1807. 



strata 



