Art. 'XII. — Th(! Mount Morgan Gold Mine, Queensland. 



By E. J. DUNN, F.G.S. 



(With Plates XXI., XXII.). 



[Eead 11th Aug-ust, 1904]. 



The \\Titer visited this mine in 1889, when the Mount was 

 ahnost in its original condition, in 1890 and again in 1894, and 

 enjoyed exceptional opportunities of examining the upper and 

 richer portion. The first survey of the mine and siuToundings 

 was made under his supervision in 1889. Several comprehensive 

 reports on the mine have been published, of which Dr. Jack's 

 three reports, issued by the Queensland Geological Survey in 

 1884, 1889 and 1892, are by far the most complete. 



In 1887 J. Macdonald Cameron published a report on the 

 mine, and since 1892 the Queensland Geological Surs^ey has 

 issued some short reiDorts about the mine ; but so far as the 

 writer is aware no clear description of the structure of the mine, 

 as disclosed to 1894, has been printed. 



In 1894 the last remnants of the highly-enriched zone were 

 removed, and the open workings at this time explained much 

 that was previovisly obscure. The several examinations made 

 by the writer were in the interests of clients, and therefore 

 the data were not available for publication until some time 

 had elapsed. 



Dr. Jack's view was that a thermal spring had deposited the 

 auriferous rock at Mt. Morgan. From this view Mr. Cameron 

 dissented. The late Mr. Wesley Hall and the then mine 

 manager (Mr. Lisle) held the view that the oxidization of 

 sulphides accompanied by heat sufficient to melt the quartz 

 even, and an inflow of water from below, caused a " chemical 

 outburst," and the gold and other material was subsequently 

 deposited (Cameron's Report). 



