OCCURRENCE OF GOLD IN THE HAWKESBURY ROCKS. 185 



Preliminary Note on the OCCURRENCE of GOLD in the 

 HAWKESBURY ROCKS about SYDNEY. 



By A. Liversidge, m.a., f.r.s., 

 Professor of Chemistry in the University of Sydney. 



[Bead before the Royal Society of N. S. Wales, October 3, 1894.'] 



I have long wished to make a systematic examination of the 

 New South Wales sedimentary rocks for the occurrence of gold 

 in them, but it was not until 1892 that I was able to commence 

 the work upon the sandstone and shale about Sydney. My 

 experiments are by no means complete, and I am only induced to 

 bring forward this preliminary note because there is rather a 

 dearth of papers for this evening's meeting. 



The Hawkesbury sandstone and Waianamatta shale are, of 

 course, derived from older, (and in all probability gold bearing) 

 rocks, hence it is not unreasonable to expect to find gold in them, 

 especially when we bear in mind that gold has been detected in 

 the carboniferous limestone and other rocks in England, (See 

 Minerals of N.S.W. 1888, p. 24); the limestone is also likely to 

 contain less gold than a sandstone. 



Gold is found in the coal measure conglomerate of New South 

 Wales, but the presence of gold in this is very natural, the con- 

 glomerate is simply an old gravel and is analogous to later 

 " cements " and similar gold bearing deposits ; the Hawkesbury 

 sandstone is in turn analogous to a gold bearing sea beach. 



The late Revd. W. B. Clarke states in his " Southern Gold 

 Fields," Sydney, 1860, pp. 44 and 244, that he had seen minute 

 specks of gold in the quartz pebbles of the sandstone on the North 

 Shore and at Govett's Leap, but no assays are quoted, and he 

 remarks in italics that he considers these have no commercial 

 value. 



