420 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



east to west ; the apparent exception in the Narbudda district is only 

 apparent, for Raniganj and Barakar are counted as one and the 

 Panchet or Trias is the Upper Damuda. Equally noteworthy are 

 the great irregularity and evidently local character of the coal 

 seams, which are hardly less striking than the small proportion of 

 high-grade coal in all of the fields. 



Siberia. 



Carboniferous deposits are exposed in broad areas within the 

 Kirghiz Steppes of western Siberia." There, according to the 

 synopsis published by the Comite Geologique, the Lower Carbonifer- 

 ous rests at times on the Devonian, at others on the metamorphics. 

 The lower portion is mainly limestone, but higher in the section the 

 prevailing rocks are gray or green calcareous sandstone, with marine 

 fossils similar to those of the limestone. This portion, however, 

 varies greatly ; in some localities it is chiefly shaly sandstone while 

 in others it is mainly black clay shale. 



Directly overlying the Lower Carboniferous is the Coal series, 

 consisting of alternating white, gray to black, more or less sandy 

 shale, with yellow to green and white clayey sandstones and some 

 seams of coal. The white to gray sandstones occasionally become 

 conglomerate, but only in limited areas. The only fossils are plants, 

 which occur abundantly in the roof or near the coal ; but these are 

 ill-preserved and, in large part, only the genus can be determined ; 

 the flora, however, is distinctly Upper Carboniferous. 



The coal-bearing rocks are in valleys, enclosed by older deposits 

 and in most localities are greatly disturbed, though the disturbance 

 is comparatively slight in a few areas. The variation in thickness of 

 coal seams is almost as notable as in those of India. Borings made 

 near Ekibas-touz, under supervision of the government geologists, 

 revealed the presence of two seams, 23 and 40 meters along a line 

 of 7 versts ; but elsewhere the total of coal rarely exceeds 6 meters 

 and, too often, the seams are merely alternating thin layers of coal 

 and coaly shale, practically worthless for industrial purposes. The 

 district between the Irtych and Ichim Rivers, south and west from 



19 Apergu des Explorations Geologiques et Minieres le long du Trans- 

 siberien," le Comite geologique de Russie, 1900, pp. 27-32, 52, 83-88. 



