408 Norman Taylor — The Cudgegong Diamond Field. 



were obtained, but not sufficient to pay. Like Miller's, tbis 

 part of tbe lead rests upon, or near to, a greenstone dyke, and tbe 

 drift contains large boulders of tbat rock. Tbe lead passes along 

 tbe east and soutb sides of a basalt hill, but the older lead, from 

 which this is a wash, must underlie the columnar basalt, and has 

 not been tried. The south-west side of the small basalt bill is 

 shallow ground. Scattered shafts on the east side of the large flat, 

 forming the " Two-mile-flat," and flanking tbe western foot of a 

 high sandstone range, running in the strike of the rocks (N. 25° W.), 

 indicate the position of the " Deep Lead." The basalt is here very- 

 little above the level of the flat, and is mostly obscured by a wash 

 of clay from the ranges. At Fitzpatrick's Claim, 80 feet of basalt 

 rests on 80 feet of drift, which was worked for gold alone, and gave 

 good results. The bottom is a soft decomposed argillaceous rock, with 

 no visible dip or strike. The gold was contained in a brown loosely 

 cemented brecciated conglomerate of quartz pebbles, sand, and 

 "floating reef" (yellow concretionary sandstone). The adjoining 

 claim (Toby's) yielded a few diamonds, all of good size, nine weighing 

 23 carat grains. On no other portion of this lead wei'e they looked 

 for. The lead runs round the head of the flat, about 2-| miles south 

 of the village of Warburton, crosses it, and then turns northerly 

 again to the river, which it joins a mile north of the village. The 

 " Two-mile-flat " — 19 miles from Mudgee — is about one mile wide, 

 by three and a half miles long, and is bounded on the west by a 

 low range running in a north-west direction from the Big Hill, on 

 the Mudgee road, about 500 feet above the flat; from thence the 

 range rises towards the north-west, on the east side of the flat, to 

 an altitude of over 700 feet above it. The general direction of the 

 ranges is determined by the strike of the rocks (N. 25° W.). The 

 dip of the beds is generally vertical, or very rarely at a high east 

 or west angle. The rocks themselves consist of red and yellow, 

 coarse and fine-grained, indurated sandstone ; thin white laminated 

 argillaceous shales ; finely micaceous red shales and sandstones ; 

 pink and brown fine-grained sandstone, banded with purple stripes 

 in concretionary rings and layers ; and hard metamorphic schists. 

 All these rocks, with the one exception named, are singularly devoid 

 of mica. Quartz-reefs occur, but ai-e apparently non-auriferous. 



Tbe late Professor Thomson shared my opinion that the age of 

 these rocks is Upper Silurian, the only fossils discovered in them 

 in situ being the Crinoidal stems before mentioned. A rounded piece 

 of sandstone, containing distinctive Upper Silurian forms, was found 

 in the drift of Buckley's lead, but has probably come from a con- 

 siderable distance ; similar pebbles, inclosing Crinoidal stems, Orthis, 

 etc., were found in the brown sandstone ("floating reef") of the 

 newer drifts on the flat — and also the cast of a Spiri/er and sections 

 of Crinoidal stems in pebbles of hard quartzite. 



On the inside flanks of the ranges on both sides of the "flat," 

 there are five small outliers of basalt, overlying the older gold drifts. 

 It was in these drifts, formerly worked for gold, that the diamonds 

 were found. The centre of the "flat" is occupied by a mass of 



