117 



discovery of it in the metamorpliic granites (micaceous or 

 tornbleudic) whicli they superiorily succeed. 



The mica slates are rich in interlaminations o£ quartz, which 

 have invariably given rise to local contortions, the amount of 

 disturbance being somewhat proportionate to the magnitude of 

 the intrusions, which sometimes is considerable. These quartz 

 masses are usually lenticular in shape, and some have been 

 found to be auriferous, and, in consequence, have been mis- 

 taken for true reefs or leaders. These interlaminations of 

 auriferous quartz may be more frequent and more widely 

 distributed than has been ascertained, and the gold drifts may 

 in some measure at least be due to their denudation. 



The exploitations for gold are so few that I cannot venture 

 to group the auriferous reefs according to the character of the 

 matrices, the direction of their lines of outcrops, or to the 

 general bearing they have to the prevailing strike of the con- 

 taining rocks. 



Distribution of Gold in the Veins. — k. summary statement^ of 

 my South Australian experiences is that the auriferous portion 

 of the vein is of limited extent horizontally, and that the 

 precious metal is not well diffused throughout the quartz, but 

 is for the most part gathered in patches, or what the miner 

 calls "pockets," so that a barren quartz occupies large sections 

 of the vein. This circumstance introduces an element of great 

 uncertainty in ascertaining the payable character of the vein, 

 and has largely operated in the past to discourage extensive 

 explorations. 



The AYaukaringa lode is the most defined at the surface of 

 all the auriferous reefs in South Australia with which I am 

 acquainted. It is traceable for.many miles, but its auriferous 

 nature, as it appeared to me on the occasion of an inspection 

 five and a half years ago, was fullest developed in the Alma 

 claim, from which on either side it deteriorated rapidly con- 

 current with the change of the matrix from a quartzose 

 haematite to pyrolusite. Nevertheless, I sincerely trust that 

 the many explorations that have been carried on during the 

 last few months on distant parts of the reef have proved that 

 my observations if correct are only applicable to the superficial 

 parts of the lode, and that they have revealed a more en- 

 couraging feature than that which was seen by me. Here I 

 may be allowed to state that I have no pecuniary interest in 

 any mine or mineral property in South Australia, and that any 

 statements of mine in reference thereto are but expressions of 

 honest conviction. 



With regard to the chances of our reefs carrying payable 

 gold in depth, I may refer, by way of introducing the question, 

 to the opinion of that celebrated — perhaps the best — authority 



