ANTHRACITE IN A FISSURE LODE, 



By LIONEL C. BALL, B.E. 



Read before the Royal Society of Queensland, \Uh March, 1911. 



INTRODUCTION. 



It is desirable that an almost unique geological occur- 

 rence — that of coal as gangue in a lead- zinc fissure lode, the 

 discovery of which was among the more interesting results 

 of my visit to the Mended Hill Mineral Field in June last — 

 should be brought to your notice and so recorded. 

 Economically the association of the coal and metallic ores 

 is likely to be of some importance, for timber is very scarce 

 in the district ; and it may be possible, in milling and 

 concentrating the ore, to save the coaly slime and use it 

 in briquette form as fuel. Further, the certainty of there 

 being a high class coal here should induce prospectors to 

 be on the lookout for a workable seam in this part of the 

 State ; notwithstanding that if it is of inorganic origin, 

 the possibility of which is shown below, no quantity of coal 

 is likely to be discovered away from fissure formations. 



STRATIGRAPHY. 

 The basal rocks of this field have generally been referred 

 to the Silurian on the evidence of certain fossils from the 

 Cairns Range, which lies 300 miles to the south. They 

 consist of grits and shales seldom much altered except at the 

 surface where they are silicified and bleached, but Dr. 

 Jack,* who visited the field two and a half-years ago, 

 discovered carbonaceous shales at the Lilydale mine, ajid 

 the work done since his visit is indicative of similar, if not 

 the same, shales occurring over an area of many square 

 miles. 



♦Report on the Lawn HiU Mines, Queensland. By R. Logan Jack, 

 L.L.D., M.LM.M., late Government Geologist. Sydney, 1908. 



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