54 Auriferous Districts of 



" Copper lodes occur in both the Upper Silurian and the Ma- 

 tamorphic series ; in both apparently due to porphyritic intrusion, 

 as the Mount "Wyatt outcrops of copper ore in fossiliferous Upper 

 Silurian are associated Avith dykes either of Porphyry or Horn- 

 blende rock. 



At the junction of the Lynd and Copperfield River, I have 

 taken up a copper lode exposed on the bank of the river ; its 

 upper and lower walls are Mica-schist ; its thickness, where it 

 is cut through in a drive at thirty feet from the surface is twenty- 

 three feet. At this depth the ore is chiefly spongy metallic copper. 



" On the east bank of the river, within ten chains of the main 

 outcrop, a mass of porphyry crosses the metamorphic schists nearly 

 at right angles to their strike, and on examination I found iron 

 and copper pyrites not uncommon constituents of the porphyritic 

 mass. 



" This dyke is continuous about five miles on the eastern bank 

 of Jardine's Einnasleigh ; it then crosses that river, and I have 

 followed it about fifteen miles westerly from that point. It re- 

 sembles very much the porphyry of Buchan River, in Gripps's 

 Land, with which district you are acquainted." 



I have now, in dealing with these researches of my friend Mr. 

 Daintree, discharged, I hope, a duty to all who are interested in 

 the prosperity of Australia. The discoveries of Grold and Copper 

 and other metals are not merely valuable to individual explorers, 

 but belong to all the colonies in general. Those who work them, 

 and those who profit by them, are of no particular section of the 

 community, nor of any given member of the Australian provinces. 

 I trust it is in fulfilment of that which we so recently announced 

 as a chief object of the Royal Society,* that I have brought these 

 discoveries before the Society to-night, " incorporating" Mr. 

 Daintree's remarks according to his own expressed desire in my 

 own paper, which I wish to be considered as a kind of progress 

 report on the older rocks of Queensland. I cannot conclude, 

 however, without drawing attention to the Photographs which I 

 now exhibit of the Lynd copper country, taken by Mr. Daintree, 

 as explaining, in a clear manner, some of the picturesque geo- 

 logical scenery of that very distant locality, at least 1200 miles 

 to the north of us by direct measurement. 



I would especially call attention to the outlines of the rolling 

 porphyritic range beyond the Alligator Pool in the Copperfield 

 River : it is the exact representation of numerous ridges of the 

 same kind in our own gold-fields. Those who have seen the 

 Araluen Range, or the Harnhum Hill at Salisbury, near the 

 Uralla gold-field, in Xew England, will at once be struck by the 

 resemblance. Again, in the view of M'Kinnon's Lynd River we 



(* See p. 26.) 



