464 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



ol shale, lo to 70 meters thick, increasing toward the west. The 

 middle portion, the Andenne of Stainier, is 130 to 400 meters, in- 

 creasing, as the Chokier, toward the west. It hac thin streaks of 

 terroulle or earthy coal, one of which, near the base, has been mined ; 

 it has a sandstone roof containing Calamites and is 40 centimeters 

 thick ; it has a true underclay, with Stigmaria. A persistent band 

 of ripple-marked sandstone, 5 to 10 meters thick, overlies the coal- 

 bearing shales and a marine deposit is near the top of this division. 

 The Gres grossier, or Poudingue houiller, the Poudingue de Mon- 

 ceau-sur-Sambre of Mourlon,^* at top of the Namurien, 12 or more 

 meters thick, varies from fine sand to coarse conglomerate. 



Dannenberg says^^ that in the Liege district the Andenne has 

 three seams, of which the middle one, V. au Gres, is the best ; that 

 at the base, V. aux Terres, is so dirty as to be worthless. Stainier^^ 

 states that, in the Andanne or eastern district of the Liege basin, 

 the Chokier consists chiefly of dark laminated shale, utilized in 

 manufacture of alum. The Andenne, mostly shale, has the lowest 

 coal seam at 80 to 130 feet meters above the Lower Carboniferous 

 limestone. It is thin, without value, and underlies a sandstone, often 

 20 meters thick. On this rests a mass of shales containing the 

 only workable seam, known as Plateur-de-Rouvroy, Pelemont, Six- 

 Mai and Grande Veine, which at times is one meter thick, though 

 usually between 50 and 60 centimeters. It is terroulle, an intimate 

 mixture of coal and clay, burning slowly and without flame. Almost 

 invariably it is in two benches, one giving fine, the other lump coal. 

 At the western extremity of the district, this seam divides, but the 

 benches retain their character. The roof is marine in the eastern 

 portion, containing Lingula and Loxonema. The poudingue houiller 

 has beds of conglomerate with pebbles, at times, of one decimeter 

 diameter ; it would seem that these conglomerate layers are merely 

 lenses. 



Smeysters^^ notes that, in the eastern part of the Hainaut basin, 

 the lower Westphalian has an extreme thickness of 350 meters, but 



5*M. Mourlon, "Geologic de la Belgique," 1880, t. i. p. 119. 



55 Geologie der Steinkohlenlager," p. 280. 



56 X. Stainier, " Bassin houiller d' Andenne," Bull. Soc. Belg. de Geol., 

 t. VIII., 1894, Mem., p. 3-22. 



5" J. Smeysters, Ann. Mines de Belg., t. V., 1900, pp. 1-128. 



