742 



THE TIN-DEPOSITS OF NEW ENGLAND, N.S.W., I. 



the numerous smaller veins which also intersect the slate. A 

 sketch of this is given in text-fig. 1. 



Fig. 1. — Plan of " Acid Granite " intrusion into slate. F, F, faults. 



At King's Gap, on the Inverell-Bundara Road, there is another 

 contact of granite and slate. The slate here is converted into a 

 mica-schist, a number of subangular fragments of which may be 

 seen as inclusions in the sranite. 



The Permian System. 



Under this system have been included the intrusive granite?. 

 These fall naturally into two groups, namely — (1) The "Acid 

 Granite" (of Andrews). (2) The Tingha Granite. 



Of these two types, it is the "Acid Granite " which is closely 

 associated with the tin-deposits. The most primitive distinction 

 between these two granites is, that the "Acid Granite" is a red 

 granite, and the Tingha Granite a blue granite. The latter type 

 is not, however, the same as that named the " Blue Granite " by 

 Mr. E. C. Andrews, and which occurs in another part- of Kew 

 England. 



The Tingha Granite. — Of the two granites, the Tingha Granite 

 is certainly the older, as it has been found in many places to 

 have been intruded by the "Acid Granite." The contact is 

 never very sharp, a zone of rock intermediate in composition 



