402 Norman Tat/lor — The Cudgegong Diamond Field. 



up by the basalt without the intervention of any drifts. The great 

 differences in level, which these latter beds occupy, deserve con- 

 sideration. For my own part, I believe, with Professor M'Coy of the 

 Melbourne University, to whom the fossil flora were submitted by 

 me, that the Guntawang and Reedy Creek beds, at the lower levels, 

 are Mesozoic. They have only been exposed in comparatively recent 

 times, by the deepening of the river channel, and no remains of 

 them are found in the older drifts. There is no trace of anything 

 like Glossopteris in them. For our present purpose it will be 

 enough to show that vast masses of Carboniferous strata have 

 suffered denudation, as, along the main stream, we find relics of 

 these rocks, not only in the present bed, but also in the older 

 drifts, but not in the oldest. 



A short distance up the Eeedy Creek from its junction with the 

 Cudgegong River, granite appears in the bed, very coarse-grained, 

 with large felspar crystals. Higher up the creek, this is overlaid 

 by basalt, which, a little below the junction of Hapdash Creek, is 

 cut through by the creek, and forms a causeway. At the Hapdash 

 Creek junction the basalt gives place to horizontal ferruginous grits 

 of doubtful age, but probably some portion of the Mesozoic beds 

 occurs lower down. 



The deep auriferous "leads" of Gulgong (N.E. of Guntawang), 

 from 80 to 150 feet in depth, are composed of a mixture of angular 

 and partly rounded quartz, in no way resembling the diamond 

 drifts, although both are covered by apparently the same basaltic 

 lava flow. The bottom of these leads is higher than the Diamond 

 leads, and no trace of gems has been discovered in them. Fossil 

 bones have been found in a more recent lead, near the Pipeclay 

 diggings, south of Gulgong, and numerous fossil fruits and plant 

 remains in leads under the basalt at Gulgong, thus indicating their 

 fluviatile origin ; 1 whilst neither fauna nor flora (except as im- 

 bedded in drifted pebbles, or as particles of ferruginous wood in 

 the conglomerates) have been found in the diamond leads, and I 

 think the latter are undoubtedly of marine or fiuvio- marine origin, 

 the circumstances and nature of the drifts having perhaps been 

 unfavourable to the preservation of fossil remains. 



The localities on the Cudgegong, which produced the diamond, lie 

 on either bank of the river, extending from the Wialdra or Reedy 

 Creek (18 miles north 80° west from Mudgee) to a point further 

 down, seven miles south-west, known as Hassall's Hill. Along 

 this line the distribution of the diamond is by no means general, but 

 is confined, chiefly, to a few small outliers of an old river drift, 

 which occur at various distances from the present river channel, and 

 at elevations varying from below the river level at the Reedy Creek, 

 to 40 feet more above it further down. This old drift is capped by 

 hard, compact, and, generally, columnar basalt. These outlying 

 hills of diamond-bearing drifts, with their basaltic coverings, though 

 once forming part of a continuous and widespread deposit, have 



1 See C. S. "Wilkinson, Annual Eeport of the Department of Mines, N. S. Wales, for 

 the Year 1876, p. 172 ; also Baron von Mueller, ibid, pp. 178-180.— E. E., j'un. 



