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



The rock was noted as far north as Glen Innes, and as far south 

 as Guyra; and it is probable that it forms a continuous belt 

 running in a north and south direction. It was shown, in a 

 former paper,* to be intrusive into the slates near Guyra. 



The three rocks above mentioned are certainly older than the 

 Tertiary basalts; and are probably also older than the Tingha 

 Granite, and younger than the elates. 



Chapter iii. — The Tin-ore Deposits. 

 The Tin-Ore Deposits. 

 The deposits map be grouped into three classes as follows — 

 (1). The Alluvial Deposits. 

 (2). The Deep Leads. 



(3). The Vein-Formations (including Stockworks and Im- 

 pregnations. 

 (1-2) The Alluvial Deposits and Deep Leads are being studied 

 in detail by the officers of the Department of Mines. Conse- 

 quently only such mention of these will be made, as is necessary 

 to indicate the distribution of the tin-deposits. Alluvial tin has 

 been found at Elsmore, Newstead, Stannifer, Gilgai, Tingha, 

 Howell, Copeton, Oakey Creek and Auburn Vale. Deep leads 

 have been worked at Elsmore, Newstead, Stannifer, Tingha, 

 Gilgai, Copeton, and Oakey Creek. At the two last-mentioned 

 places, tin has been recovered in connection with diamond-mining, 

 (3) The Vein-Formations. — At all the localities aforementioned, 

 the tin occurs as cassiterite, and has been derived from the vein- 

 formations. The tin-deposits are intimately related to the " Acid 

 Granite," numerous deposits having demonstrated that these ore- 

 bodies occur normally at, or near, the junction of this rock with 

 either the Tingha Granite, or the slates. Those occurrences 

 distant from these junctions occupy the crests of the granite- 

 ranges, and were probably close to their contact with the over- 

 lying slates, which have been removed by denudation. This 



* Cotton, Leo A , '* Note on the Guyra Lagoon." These Proceedings, 

 1909, p. 233. 



