STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



463 



The succession in Belgium is sufficiently clear, though, owing to 

 the extreme distortion along the southern border, some localities re- 

 main, in which relations are somewhat uncertain. The order as 

 given by Renier is 



Slephanien 



Westphalien 



Absent 



Superieur 



Inferieur 



'Assise de Flenu (Renier) 

 Petit-Buisson 

 Assise de Charleroi (Stainier) 

 GrO'S-Pierre = Stenaye 

 .Assise de Chatelet (Stainier) 

 Poudingue houiller 

 xA-ssise d'Andenne (Stainier) 



Veine aux Terres 

 xAssise de Chokier (d'Omalius) 



Binantien or Lower Carboniferous. 



This is equivalent to the grouping presented by de Lapparent and 

 Munier-Chalmas. Stainier prefers to limit the term Westphalien to 

 the upper three assises and to apply the name Namurien to the lower 

 part of the section. This nomenclature has been accepted by Dan- 

 nenberg in his description of the Belgian fields. The coal seams, 

 Petit-Buisson, Gros-Pierre and Veine-au-Terres are at or very near 

 the base of the several assises. The number of marine horizons 

 decreases upward ; it has been suggested that some relation may 

 exist between quality of coal and the origin of the rocks; Chokier, 

 essentially marine, is wholly barren ; Andenne has marine horizons 

 and little coal, which is true also of Chatelet ; but Charleroi, without 

 positively marine deposits, is rich in coal ; Flenu has but one marine 

 deposit, that in roof of Petit-Buisson at the base, and this assise has 

 much coal.^^ 



Formerly, the Coal Measures were divided into Hi, a, b, c, and 

 H2, the former being the Namurien, the latter being the Westphalien 

 or upper Westphalien. The general features of the lower division 

 were described by Purves.^^ The Chokier, or basal assise, is a mass 



^^ These details are mostly from A. Renier, " Les gisements houillers 

 de la Belgique," Ann. Mines de Belg., t. XVIII., 1913, pp. 757, 759, 767, 773. 



S3 J. C. Piirves, " Sur le delimination, etc., de I'etage houiller inferieur de 

 la Belgique," Bull. Acad. Roy. Belg., III., t. II., 1881, sep., pp. 1-57. 



