816 DIAMOND-DEPOSITS OP COPETON, N.S.W., 



examined, and the Tertiary streara-cliannel reconstructed as 

 shown. A short description of the various places, where diamonds 

 have been found, will serve to connect these, and to illustrate 

 their relationships. 



The most southern claim is that known as Rider's Lead. 'J'his 

 lead heads on the present divide, between Maid's Creek and 

 Sandy Creek, at an elevation of about 2,600 feet above sea-level. 

 This is near the junction of the Acid with the Tiugha granite, 

 but the lead itself lies chiefly within the Acid granite-area. 

 Very little basalt is now present, and the greater portion of the 

 lead is now concealed by alluvial deposits at a depth of about 

 50 feet. The characteristic feature of this occurrence is the 

 zone of pipeclay, which overlies the drift and wash. Owing to 

 the neglected state of the workings, I was not able to investigate 

 underground; but, from information supplied by Mr. Skippen, it 

 would appear that the body of wash was not more than a few 

 inches in thickness. This was overlaid by about three feet of 

 rather coarse drift (containing pebbles up to 1cm. in diameter), 

 and the whole covered by two or three feet of pipeclay. The 

 basalt-capped part lies three-quarters of a mile below the head of 

 the lead. It is probable that, when this lower portion was over- 

 whelmed by basalt, a lake was formed in which the fine kaolin 

 from the decomposition of the felspars was deposited. There is 

 no evidence that the head of the lead was ever covered by basalt. 

 Little success has attended the exploitation of the deposits 

 underlying the basalt, most of the diamonds having been won 

 from that part underlying the alluvial deposits. 



The minerals associated with the diamond in this lead are 

 tourmaline, topaz, tinstone, jasper, and garnet. The diamonds, 

 as usual, were recovered from the wash, in which they were 

 irregularly distributed. Several good finds were made in small 

 potholes. The stones were of better size and quality than the 

 average production of the Copeton field, and numbered about 

 three to the carat. Bort is also recorded from this locality. 



Following the lead north, the next place where diamonds have 

 been found is at Kenzie's claim. Here the lead has been almost 

 entirely swept away by the present cVeek, but a small area of 



