444 PROCEEDINGS OF SECTION C, 



described as being composed of quartz, felspar, and mica. It would 

 be interesting to know whether the felspar is mainly orthoclase or 

 albite, as the latter is so characteristic of tantaliferous dykes. 



Silverton and Darling Range. — In a recent letter Mr. C. W. Marsh 

 says : " About two miles east of Silverton (Barrier Eanges) there is a 

 large granitic outcrop, from which building stone has been quarried, 

 having as accessory minerals tourmaline (black and red), ilmenite, 

 garnets, and a little wolfram and columbite. I also remember finding 

 columbite in granite at the southern point of the Darling Range, in the 

 Rock Well Paddock, Barrier Ranges." 



Victoria. — So far no tantalum or niobium is known to occur in 

 this State. A mineral discovered some years ago, and reported to be 

 columbite, proved on further examination to be rutile. 



South Australia. — As we leave the eastern side of Australia we 

 find more frequent occurrences of these rare metals. 



Boolcomatto and Mount Bahbage. — In the previously quoted letter 

 of Mr, C. W. Marsh, that gentleman gives the following particulars 

 with regard to discoveries made by him apparently between 1885 and 

 1895 : '■ Sent from Broken Hill to Boolcomatto, S.A., to inspect sup- 

 posed important tin find, which turned out to be a large granite out- 

 crop, containing as accessory minerals ilmenite and tourmaline, with a 

 little wolfram and columbite. .... Sent from Broken Hill to 

 Mount Babbage, on the northern end of the Fhnders Ranges, S.A., to 

 supposed valuable tin discovery, which turned out to be a deposit in 

 creek bed consisting principally of dark garnets, with a little titanite 

 and one large flat piece of columbite, with several small fragments of 

 tantalite." 



Northern Territory. — In a report on the north-western district 

 of the Northern Territory by Messrs. H. Y. L. Brown and H. Basedow, 

 recently published by the South Australian Government, a short des- 

 cription is given of the occurrence of tantalum ores in that region. 

 Three localities are mentioned, all within 30 miles of Port Darwin, in 

 tin-bearing country. 



Finniss River. — This is apparently the only locality where tantalite 

 is being raised for the market. The deposit was discovered 20 years 

 ago, and worked for tin, the tantalite not being recognised as such until 

 recently. As in so many other cases, it was — -probably on account of its 

 similar specific gravity — assumed to be identical with the tin ore which 

 accompanied it. Messrs. Brown and Basedow described the deposit 

 in the following terms : — " The ore-carrying body consists of a huge 

 intrusion of greisen, trending south-westerly, with a slight underlie to 

 the east. The outcrop measures from three to four chains in width, 

 and about six chains in length. It is characterised by immense, com- 

 pact, white inclusions of quartz. The texture of the matrix varies 

 from abnormally coarse to sugary, the latter type of rock often con- 

 taining epidote. Tantalite occurs practically throughout the mass , 

 but is very erratic in its appearance as small bunches and isolated 

 crystals. It assumes three modifications, depending largely upon the 



