410 STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 



former asserted that the fauna was absolute proof of Paleozoic age. 

 It may be well to recall that this fauna reappears in Queensland at 

 top of the Bowen formation. 



According to Mackenzie,^ the coal seams of the upper measures 

 are much broken by partings, usually thin. The seams, at times, are 

 thick, 8 to 26 feet, but much of the coal is poor. A faux-toit, con- 

 sisting of coarse coal and "coal and bands," 4 to 12 feet thick, is 

 present at many localities. The benches frequently differ in char- 

 acter of the coal. The roof and floor are usually shaly clay and in 

 most cases the roof is plant-bearing. The coal seams of the lower 

 coal group are much divided and show great difference in the several 

 benches. Occasionally the underclay is crowded with Vertebraria. 



The lens shape of coal seams is a by no means rare feature. The 

 important seam at Greta suffices for illustration.^ At the Greta 

 mine, it has 6 benches, including one of Kerosene shale, and is. 26 

 feet thick, inclusive of 6 feet of partings and inferior coal ; but 

 within 32 chains it becomes only 17 feet 6 inches, while at three 

 miles north it is but 7 feet 6 inches and the Kerosene shale is want- 

 ing. That shale occurs as lenticular deposits 'with the seams, and 

 bears close resemblance to cannel in mode of occurrence. Liver- 

 sidge^ states that at Joadja Creek this mineral contains Glossopteris 

 and Vertebraria. The fronds of the former usually are spread be- 

 tween the laminae but the latter crosses them. 



David^ says that the Stony Creek and Greta coal measures, under- 

 lying the Upper Marine Series, are thin at the south but become 

 thicker northward, the increase being due to splitting of an impor- 

 tant coal seam into several thinner ones. At East Maitland, he saw 

 in the East Maitland (Tomago) series a coal seam, consisting of an 

 upper division, clays and coal, 4 feet, and a lower division, coal and 

 thin partings, 4 feet. At little way northward, the divisions have 

 become distinctly separate seams and, at another locality farther 

 north, the interval between them is 140 feet. In a later report, he 



^ J. Mackenzie, " Mines and Mineral Statistics," pp. 209-243. 



6 Annual Rep. Department of Mines, 1883, p. 149. 



''' A Liversidge, " Description of the Minerals of New South Wales," 

 Sydnej% 1882, p. 160. 



ST. W. E. David, Ann. Rept. Dept. of Mines for 1887, pp. 147, 149, 151; 

 the same for 1890, p. 229. 



