446 Norman Taylor — The Cudgegong Diamond Field. . 



of the hill there is from 80 to 90 feet. The drift underlies it in 

 two distinct leads, from north to south, in the centre and west of 

 the hill, hut not on the east. The leads form a sort of elongated 

 ellipse. The concavity of the hill faces south-west and the horns 

 are nearly connected by the lower or more denuded portion of the 

 flow. In the innermost portion of the concavity, which rises gradu- 

 ally to the table-topped main mass, a shallow hole exhibits a fine 

 friable thin-bedded greyish white sandstone, inclosing perfect, but 

 minute, double hexagonal pyramids of quartz. This is evidently 

 the top of a hill or island, round which the old river, and subsequent 

 lava-streams, have flowed. The denudation not having been so 

 extensive here as on the upper portions of the lead, a greater 

 width of basalt and increased thickness of the underlying drift is 

 the result. In the easterly lead, where it curves round to the 

 south horn, as much as one ounce of gold to the load was obtained ; 

 but, from the length of time occupied in sinking the shafts (over 

 five months), it was unprofitable. Some very long drives were put 

 in, and a few diamonds were obtained, but the area was never 

 specially worked for diamonds. The rock on the top of the hill 

 consists of from thirty to forty feet of loose concretionary basalt, 

 getting denser below, and resting on vertical columnar basalt. The 

 whole of the upper stratum has been denuded away from the lower 

 ground. On the south face of the central sandstone hill is a small 

 shallow lead, which must be the edge of the older drift, resting 

 against the sandstone island, and now exposed by denudation. A 

 similar instance occurs again near the apex of the southern horn ; 

 where the basalt of the northern horn nearly joins that of the 

 southern one, the ground is quite shallow (about 12 feet deep), but 

 deepens westerly to 30 feet, and contains very large semi-angular 

 blocks of quartz, and much " cement." The south side of the 

 southern horn was worked, and yielded a few diamonds, but 

 not much gold. The drift is full of large semi-angular blocks of 

 quartz, and is a side wash, as the ground dips to the north. The 

 quartz, from its character, is, in a great measure, derived from veins 

 in, or in the neighbourhood of, greenstone. In the deepest parts of 

 the leads the quartz boulders are all perfectly rounded. The richest 

 diamond claim discovered was situated at about the centre of an 

 imaginary line joining the two horns ; it was owned by a working 

 party of miners — Messrs. Cooney, Hennessy, Ward, and others. 

 Their shaft, sunk to the depth of 51 feet, shows 27 feet of basalt, 

 resting on brownish-yellow sand, and that again on alternating 

 sandy, gravelly, and pebbly beds, mostly loose and friable, with 

 occasional thin layers of ferruginous " cement." The whole of the 

 drift below the basalt had to be very securely slabbed, as the fine 

 sand runs like water. In their southern drive there are three 

 distinct veins of very loose granitic quartz detritus, separating, and 

 alternating with, the gem-bearing veins. These gradually cut out, 

 going north, and the gem-wash becomes more solid. There is also 

 a bed consisting entirely of loose and open quartz pebbles, super- 

 ficially covered with a brownish-black greasy-looking coating of 



