62 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



bed averages about 2 meters. Sometimes it is without partings but 

 at others it is broken by two, 20 to 50 centimeters thick. Occasion- 

 ally, one of the other beds is thick enough for mining, but in all 

 cases the thickness shows much variation. The coal is of very fair 

 quality ; in the Barod area, moisture is from 8.2 to 10.4 per cent, and 

 the ash is from 7.1 to 15.7 per cent. 



In the Lower as well as in the Upper Cretaceous, coal seams 

 accumulated on border areas, where the sediments show proximity 

 to land. The character of the deposits, the lens-shaped coal seams 

 and the fresh-water fauna associated with them seem to justify the 

 suggestion that the coal was formed in swamps on great irregular 

 river plains. For the most part, these had a comparatively brief 

 existence and were subject to frequent floods carrying muddy water. 



Australasia. 



Molengraaff^* reports that he saw thin seams of coal at various 

 horizons in the Cretaceous along several rivers in central Borneo. 

 These are without economic importance. The associated sandstones 

 frequently contain grains of coal. 



Coal is present in the Cretaceous of eastern Australia, though 

 very rarely in economic quantity. As the conditions appear to be 

 much the same throughout, it suffices to consider the phenomena in 

 Queensland as described by Jack.^^ Cretaceous deposits cover a 

 great part of that province, where they are divided into the Upper 

 or Desert Sandstone and the Lower or Rolling Downs formation. 



The Desert Sandstone formation, now remaining in barely one 

 twentieth of its original area, consists mostly of thin flags, whose 

 surfaces are covered with a network of raised lines, crossing each 

 other at all angles, which clearly represent filled sun cracks. The 

 same sands show tracks and burrows as well as indeterminate re- 

 mains of plants. Cross-bedding is quite characteristic of the thicker 

 layers. Pebbly deposits occur occasionally and, at one locality, 

 Gibb saw an angular quartzose grit which passed into brecciated 



^* G. A. F. Molengraafif, " Geological Explorations in Central Borneo," 

 Eng. ed., Leyden, 1902, pp. 202, 217, 241, 250, 277, 318. 



15 R. L. Jack and R. E. Etheridge, Jr.. " Geology and Palseontology of 

 Queensland," Brisbane, 1892, pp. 397-403, 51 1-536, 55i. 558. 



