Northward Extem^lon of Derriiud Con glome rate. 205 



conglomerate is represented by small, subangular fragments of 

 claystone in a light grey clayey matrix, with bands of ferruginous 

 character near the floor, total thickness of tlie conglomerate 22 

 feet. Above the conglomerate is 13 feet of black shale, then 9 

 feet of black shale and impure coal (bass), then 4 feet of black 

 shale and 1 foot of grey shale full of Gangamopteris and other 

 plant-i'emains, then 7^ feet of black shale and dirty coal. Above 

 this is a massive coal seam 27 feet thick, covered by light grey 

 false-bedded sandstone with plant impressions. Further west- 

 ward Post Pliocene deposits obscure the older rocks for about one 

 chain, then yellowish-grey sandstones again crop out. Two 

 hundred yards further west granite occurs, and this forms a range 

 running N. and S. for some miles. The Derrinal Conglomerate 

 and conformable overlying shales, coal, etc., all dip westward at 

 about 56°, and as they were probably laid down in a more nearly 

 horizontal manner a fault is indicated apparently near their 

 junctions with the granite. The granite is older than the 

 conglomerate, as proved at Cherry Gully Railway Station, Queens- 

 land. 



This remarkable coal seam was reported upon by Professor 

 David in 1883 and by Mr. Pittman, Govt. Geologist, in 1896,^ but 

 the interesting nature of the conglomerate associated with it 

 appears to have escaped notice. 



The practical importance of this section in w-hich the Derrinal 

 Conglomerate is associated with a tliick and valuable seam of coal 

 is not confined to Australia alone, for in South Africa the 

 corresponding glacial conglomerate (which I named " Dwyka 

 Conglomerate," after a site where it is characteristically repre- 

 sented) is associated with black and coloured shales as at Ash ford 

 Coal Field. Glossopteris, Gangamopteris, etc., occur in the shales 

 just above the the glacial conglomerate both in South Africa and 

 in Australia, and sub-Karroo coal seams will no doubt be found 

 that will correspond with the Ashford seam. 



In the Quarterly Journal of the Geological Society (London), 

 Vol. LIII, Part 3, No. 211, p. 310 ef seq., August, 1897, a paper 

 is published by Mr. David Draper on the occurrence of Glossop- 

 teris, Gangamopteris, etc., associated with coal seams at 



1 Records Geological Survey of N. S. Wales, vol. v., part i., page 26. 



