June] GEOLOGY AND MINERALOGY. 231 



(subsequently) with arsenical iron pyrites, and in the cavities the 

 crystals of quartz are seen with their apices pointing towards 

 each other. The same peculiarity is not unfrequently observed 

 in large leads. At Waverley the movement has occurred between 

 the quartz and the Whin, or between the quartz and hard slate^ 

 or in bands of slate, and in all cases slickensides, reed-like 

 markings, ripples and smaU undulations have been produced. In 

 the Barrel Quartz no sliding motion is distinguishable, for the 

 corrugations extend far into the overlying Whin rock until they 

 assume the form of a series of connected arches five, six, and even 

 seven feet in width. The corrugations are by no means confined 

 to the quartz lead, but spread out, fen-like, into the overlying 

 rock. At Montague the ripples or swells are at an angle of 45°, 

 and are frequently from five to eight feet apart, and the swell 

 rises as much as six inches above the plane of the bedding, the 

 laminae of the wall rock conforming to it. At Lawrencetown 

 there are similar large ripples, but at an angle of about 30°. 

 The leads in question, both at Montague and Lawrencetown, are 

 synclinal forms. It is a popular belief that in the vicinity of 

 these swells the lead is more productive than between them. It 

 appears to be well established at Montague that the nodules of 

 arsenical iron pyrites containing free gold, are more numerous 

 and of larger proportions close to the swell than at a distance 

 from it. But lenticular masses of arsenical iron pyrites are 

 found in the Whin, remote from any visible vein, unconnected 

 with one another, and sometimes lying at right angles to the 

 bedding. 



At Hammond Plains there are immense beds of feebly 

 auriferous quartz, as much as 20 feet thick, and in these crystals 

 of oxide of zinc are numerous, besides numerous cavities lined 

 with crystals of calcareous spar ; the surfaces of the crystals are 

 spangled with cubical iron pyrites. At Renfrew, where the 

 strata have evidently slid over one another, crystals of calcareous 

 spar are common, and sometimes form as much of the lead as 

 the rich gold-bearing quartz itself; these occur on the Free 

 Claim, where a considerable twisting of the strata has taken 

 place, and short unconnected, bnt thick auriferous veins, fill the 

 cavities formed by the movement, which are newer than, and 

 wholly distinct, from the bedded leads, contemporaneous with 

 the strata. While the gold which the bedded leads contain, 

 in common with the other metals, was most probably derived from 



