NOTE ON COPPER IN ANDESITE. 49 



NOTE on COPPER in ANDESITE near LAUTOKA, 



FIJI. 



By H. I. Jensen, b. s<$., Macleay Fellow of the Linnean 



Society of N.S.W. in Geology. 

 (By permission of the Council of the Linnean Society.) 



[Read before the Royal Society of N. S. Wales, August 7, 1907. ] 



Introduction.— A number of rock specimens gathered in 

 the vicinity of Lautoka, Viti Levu, have been forwarded 

 to me by the collector, Mr. Dan Petersen, for identification 

 and examination. In the collection there was a specimen 

 of copper ore with portions of the andesitic matrix im- 

 bedded in it and adhering to it. The specimen weighed 

 about 8 ounces. 



I communicated with Mr. Petersen enquiring whether 

 any slates, granites, diorites or other metamorphic or old 

 plutonic rocks were found in the vicinity, and received a 

 reply stating that as far as he was able to ascertain, only 

 such rocks as he had sent me, namely andesites, occurred 

 in the vicinity. The specimen has the appearance of a 

 segregation or metasomatic replacement product in the 

 andesite. It is of a dark colour, varying from brown to 

 bluish-black, and iridescent. 



Other Similar Occurrences.— The occurrence of copper 

 ore in andesite is not uncommon. Small quantities of 

 copper occur in the tuffy beds of the chocolate shales at 

 Narrabeen, N.S.W. In the andesitic tuffs of the Blackall 

 Ranges, nearNambour and Yandina, Queensland, a greenish 

 stain due to copper is of common occurrence. The andesites 

 of the Bumbo quarry in the Kiama-Jamberoo district con- 



D-Aug. 7, 1907. 



