546 THE GEOLOGY OF NEWBRIDGE, NEAR BATHURST, N.S.W., 



corroded calcite, and many perfect rutile cr3'stals, frequently 

 geniculately twinned. At the Belmore Copper Mine (Cow Flat, 

 Parish Ponsonby, and about five miles north-east of Caloola) this 

 replacement of calcite by chlorite is very common, and here also 

 the silicate actually associated with the ore is actinolite, so much 

 so that the ore appears to be in a country rock of actinolite 

 schist, which the microscope shows to be only a limestone almost 

 entirely replaced by the actinolite. Mr. W. J. Clunies Ross, 

 B.Sc.,* has analysed the chlorite and actinolite; he shows the 

 chlorite to be a hydrous silicate of alumina; and, for the actino- 

 lite, he gives figures proving it to be essentially a magnesia-lime 

 silicate with smaller amounts of iron and alumina. The analysis 

 corresponds to a typical analysis of actinolite given by Dana.f 



Seeing that, both at Caloola and at Belmore, the copper pyrites 

 occurs with actinolite metasomatically replacing the limestone, 

 it appears probable that the one solution deposited both of these 

 minerals, i.e., the sulphidic cupriferous solution also contained 

 the silicate actinolite. The solution that brought up chlorite 

 was probably connected with this same metalliferous solution. 

 The Belmore vein appears to correspond more closely to the 

 sericitic silver-copper type of Lindgrent than to any other of the 

 types he mentions. 



The marbles of the Caloola quarries have been analysed by the 

 Department of Mines with the following result: — § 



100-09 99-96 99-96 



These figures show that w^iile dolomite does not appear to 

 occur in the marble, magnesium carbonate is present in quite 



* Report of the Seventh Meeting of the Australasian Assoc. Adv. Sciencer 

 Sydney, 1898, p.384. 



+ System of Mineralogy, p. 393. 



X Genesis of Ore Deposits, p. 596. 



§ Ann. Rept. Dept. Mines New South \Yales, 1904, p. 147. 



