410 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



more than 20 per cent. As the samples were clearly supposed to 

 represent the average coal mined, they mark only the best and serve 

 to indicate the general inferiority. 



The Aurunga and Hiitar fields are somewhat more than 100 

 miles west from the Raniganj field. There, according to Ball,^^ the 

 Lower Gondwana is overlapped by the Machadeva or Lower Jura, 

 which, west from the Aurunga River, rests on metamorphic rocks. 

 There is no coal in the Talchir. Ball thinks that the Karharbari 

 coals belong to the Talchir rather than to the Barakar, though the 

 associated rocks are similar to those of the Barakar. 



In the Aurunga field, the Barakar deposits are sandstone grits 

 and conglomerates with huge seams consisting mostly of carbo- 

 naceous shale, which occur " at various horizons and with most 

 irregular lateral expansion." The deposition was confused ; over- 

 laps are frequent ; changes in character and thickness of individual 

 deposits are abrupt; pebbly conglomerates pass into breccias. The 

 Barakar is about 1,500 feet thick in this field and the coals are of 

 inferior quality. In the Hutar field, the Talchir is overlain on the 

 western side by conglomerates and sandstones, resembling those 

 of the Lower Jura. Coal is present in the Barakar on the Dauri 

 River and westward, but it is wanting east from that river. The 

 great irregular seams are not here but, instead, there are thin seams, 

 often yielding good coal ; these are intercalated in the sandstones 

 within a vertical space of about 200 feet. 



In both fields, the Barakar overlaps the Talchir and the seams 

 of coal and shale are often of notable thickness. In a section near 

 Rajbar, only 271 feet long. Ball measured 9 seams, about 10, 12, 83, 

 7, 13, 13, 21, 12, 24 feet, consisting mostly of carbonaceous shale 

 with many streaks of poor coal. A sample from one seam, which 

 looked like good coal, had only 22 per cent, of fixed carbon but 50 

 per cent, of ash. Similar conditions exist on the Sukri River near 

 Toobed, where two seams were seen, yy and 36 feet thick. This 

 coal zone thins away toward the southeast. A zone of rippled sand- 

 stone was seen near Toobed. In the Hutar field there are four 

 seams, i foot 3 inches to 8 feet thick, with much carbonaceous shale 



13 V. Ball, " On the Aurunga and Hutar Coal-Fields," Memoirs, Vol. 

 XX., 1880, pp. 1-127. 



