STEVENSON, COAL BASIN OF DECAZEVILLE, FRANCE 257 



contrast with conditions to be described in the Bourran bed ; and it is un- 

 expected, for on the western side of this decouverte, one finds the most 

 complicated of the folds in this basin. 



The conglomerate, overlying the coal in some places but separated from 

 it by clay shale at others, is recognizable at once as that belonging in the 

 Campagnac system. In ascending order, the succession at Tramont is 



Feet 



1. Conglomerate, light gray ; pebbles vary from grains to 10 



inches, ordinarily not more than 3 inches, though those of 

 4 inches are abundant ; white quartz, microgranulite, white 

 mica schist and gneiss are the rocks represented ; some 

 large chunks of shale as well as irregular blocks of coal 

 were seen in the lower portion 9 



2. Sandstone, somewhat argillaceous, not coarse grained, a few 



pebbles, much cross-bedded; contains streaks of coal and 

 coaly material 3 



3. Conglomerate, like No. 1, except that the pebbles are not so 



large 5 



The dip is eastward like that of an underlying coal ; it 

 passes rather abruptly into 



4. Sandstone, fine grained and cross-bedded above, where it is 



markedly argillaceous ; the lower portion contains some 

 pebbles, but they are small and not abundant; lenses of 

 coal, 2 to 3 feet long and 2 inches thick 8 feet to 12 



5. Massive conglomerates, closely resembling Nos. 1 and 3, 



divided by an occasional shaly bed 40 



Still higher beds are here, but they were not measured. Evidently 

 there is a succession of mostly coarse conglomerate for more than 150 feet 

 above the Paleyrets bed. Some petty faults were seen in the eastern wall 

 near the line of measurement, but the largest is barely 10 feet. The 

 whole series, coal and conglomerate, has the same dip; but the contact 

 between the conglomerate and the upper parts of the coal bed shows nota- 

 ble uncomformability of erosion. At times, everything has been removed 

 down to Fo. 6 ; occasionally the upper portion of ISTo. 2 was lifted like a 

 flap and the mass of pebbles thrust in under it as a wedge. At several 

 places, the top coal is bent down under the conglomerate, the laminae fol- 

 lowing rudely the contact between coal and conglomerate; at some other 

 places the upper layers of the section were shoved into irregular folds and 

 conglomerate occupies the synclinals. It is evident that the passage from 

 coal making to deposition of conglomerate was very abrupt and that the 

 coal, though perhaps well advanced in transformation, was still imper- 

 fectly consolidated. 



In the western wall, the coal and the accompanying rocks have been 

 pushed into an exceedingly close double fold. This begins at a little dis- 



