AIWIVERSAET ADDRESS. 23 



Such was the effect that produced much of the gold at Hill 

 End and Tambaroora, as well as elsewhere in the Western districts 

 of this Colony. 



The transmuted rocks at Hawkins's HUl, in which the lodes 

 occur, are so much like those that have made G-ympie so cele- 

 brated that I can see on actual comparison no essential difference, 

 except that the latter contain fossils which are yet wanting in the 

 former. 



Then, if we look to the lodes themselves, many of them contain 

 quartz only as an adventitious substance, or as mixed up with 

 mica, calc spar, and mundic, amongst which the gold is indis- 

 criminately sprinkled. I pointed out, some time since, to a gen- 

 tleman engaged in mineral surveys at Hill End, that some of these 

 lodes, so far from being true quartz-veins are clearly derivative 

 from the action of a transmuting agency, and have their nearest 

 resemblance to that variety of mica-trap which the Grermans call 

 Eraidronite. The casing, which has sometimes been mistaken for 

 chlorite slate, appears to me to be often the result of the influence 

 of lime on the materials of the transmuting rock, and is of similar 

 character to what may be observed on the faces of columns in 

 quarries of basalt. The slates and shale, which are the main 

 rocks of the region in question, are, I presume, very much younger 

 than any true chlorite slates, and are, so far as my experience 

 goes, not older than Silurian. But no fossils have yet been 

 detected in them nearer than Louisa Creek and the Meroo. The 

 Hill End country is occasionally to the westward traversed by 

 porphyritic and syenitic intrusions. A rock resembling Phonolite 

 may be traced all through the Tambaroora series exposed in the 

 old workings of the diggers, and ranging side by side with the 

 quartz reefs towards the Turon. The trappean schists are, like 

 those of G-ympie, charged with carbonate of lime, and effervesce 

 with acids. An overflow of vesicular basalt crests Bald Hill and 

 some of its slopes ; and at Frederick's Yalley Creek (Ophir) is 

 strongly developed, covering auriferous deposits over slates of 

 the same age as those of the country from Hill End to Sofala and 



