Coal District of St. Etienne. 3 



The latter are composed, if the expression may be allowed, 

 of the more or less divided debris of the basin that con- 

 tains them ; these debris are disposed in beds of variable 

 appearance alternating with others of coal and shale, which, 

 besides the greatly triturated debris of which they are 

 composed, contain vegetable remains in different states of 

 preservation. 



The following is a list of conglomerates (Poudings), sand- 

 stones, shales, and coal beds, filling up the coal basin.* 



1. Conglomerates formed of large fragments of primitive 

 mica and talcose slates and granite, scarcely cemented to- 

 gether ; these fragments are often of several cubic metres 

 content. (Fine specimens on the north of St* Etienne to- 

 wards Fouillouse ; at Rive de Gier, between that town and 

 the bridge of la Madeleine, &c.) 



2. Conglomerates composed of smaller sized fragments, 

 cemented together by the ordinary sandstone of the coal 



measures. (These conglomerates are of more frequent oc- 

 currence than the last). 



3. Large grained sandstone mixed with small rolled 

 fragments of different rocks. 



4. Compact sandstone, the grains of an uniform size, con- 

 taining plates of mica. (This is the building-stone known 

 in the country by the name of Molasse). It forms beds of 

 considerable thickness. 



5. A fine grained sandstone, in thin beds. 



6. A fine grained slaty micaceous sandstone, the slates 

 being very thin. 



7. A friable micaceous slate, in which small grains of 

 sand are distinguishable. 



8. A more compact schist, in which mica is still visible. 



9. A harder schist. This kind is the least common. 



10. Coal, containing little bitumen, earthy, and mixed 

 with schist. (This bed is found at Tartaras, Saint-Chamond, 

 and at Rive de Gier, and is known by the name of batarde.) 



* This enumeration agrees in many respects with that given by 

 M. de Bournon, in his Essai sur la lithologie du Forez. 



a2 



