STEVENSON, COAL BASIN OF DECAZEVILLE, FRANCE 265 



coal is under the surface on the western side and its overlying laminated 

 shales are shown in the bluff behind the machine house, a northward fall 

 of fully 500 feet in less than half a mile. The coal is traceable directly 

 from the Fraysse to the Domergue decouverte and the lower portions 

 have been mined at several places along the hill descending to the Banel. 



The dip of the coal is sharply westward on the hillside facing the 

 Enne valley. A serious and somewhat complicated fault exists between 

 the Fraysse area and the hill west from Cransac, where one finds the 

 outcropping Couche du Crol, the same bed. This fault apparently de- 

 creases toward the north.. 



The section above the coal in Domergue decouverte is 



Feet 



1. Sandstone, more or less conglomeratic, in thick beds, xiii, xii. 60 



2. Sandstone and shale, xii 15 



3. Shale, light colored, xi 4 



4. Shale, dark with ironstone, xi 10 



5. Shale, fissile, bluish gray, xi 20 



6. Sandstone and shale, the sandstone in part laminated and 



cross bedded, xi. x 12 



7. Shales weathering dark, x, ix, viii 40 



8. Sandstone, light gray, viii, vii 9 



9. Shales, 4 feet to viii, vii 20 



10. Sandstone, light gray, fine grained, vii, vi 8 



11. Shales and sandstones, laminated throughout ; thickness can- 



not be determined exactly from the exposures ; is very 

 undulating on the benches ; extremely flexed at west end of 

 decouverte ; appears to rest directly on the coal south from 

 the La Gua road ; thickness not far from 50 



So that the inten^al from the coal to the first of the conglomerates sand- 

 stones is approximately 170 feet, filled mostly with argillaceous shale. 

 No trace of coal was seen anywhere in this interval or in the sandstones 

 above, of which only 60 feet were measured. The exposure is complete 

 throughout. The coal is mined by shaft on the east side of the decou- 

 verte. The removal of material in the open work is by benches and the 

 Roman numbers in the table indicate the benches on which the expo- 

 sures occur. 



This decouverte cuts the axis of the Cransac-La Montet anticline, but 

 exposures are very poor below the fifth bench. In great part, the exposed 

 coal has been destroyed by spontaneous combustion, and fire is still at 

 work; the hill is known as the "volcano," for clouds of smoke rise from 

 many fissures. The coal, below the surface on both sides, rises midway 

 to the seventh bench, about 150 feet below the summit on the La Gua 

 road, where only the lowest part of the bed is shown. 



