68 CENTRAL AUSTRALIAN 



[ Copy.] Government Geologist's Office, Adelaide, 



November 30th, 1889. 



Sir — In accordance with your instructions, I have examined the 

 specimens of rocks and minerals brought by Mr. Tietkens from 

 Western Central Australia. 



The specimens from Mount Sonder indicate the occurrence of 

 ferruginous veinstones in clay slates and quartzites, and show that 

 there is a probability of the occurrence of metallic minerals, in- 

 cluding gold. The same may be said of Mount Rennie, Laura 

 Vale, Mount Leisler, Bonython Range, and Basedow Range. 



The remainder of the specimens, with the exception of those 

 from Mount Olga and Ayers' Rock, which are isolated hills, are 

 chiefly from tertiary and secondary formations, and the country 

 represented by them is not likely to contain metallic minerals. 



The whole collection is valuable as giving a good idea of the 

 geology of a part of the interior which hitherto was unknown. 

 I have. &c, 



H. Y. L. BROWN, Government Geologist. 



The Hon. Commissioner Crown Lands, &c, &cc, Adelaide. 



