of Victorian Auriferous Occurrences. 27 



the bedding planes or nearly so ; brownish granular masses ; 

 veins in the quai-tz and country rock and patches in the quartz, 

 these show district cleavage ; and crystals in the cavities of the 

 quartz. Albite and dolomite are not by any means confined to 

 Ballarat l)Ub are widely distributed in occurrences of this type. 

 Albite is less often recorded but this is easily accounted for by 

 its frequent alteration and its less easy recognition. 



Carbon occurs in the carbonaceous slates of the country rock, 

 on the walls of the reefs which not infrequently follow the course 

 of these carbonaceous slates, and as the laminations or fine 

 sub-parallel seams in the quartz. In some cases these lamina- 

 tions consist in part of other minerals. Highly lustrous graphite 

 appears to be found chiefly on the planes of movement and in 

 rocks which have undergone more than the usual amount of 

 alteration, as at Stawell and at Piggoreet. 



Order of Crystallization. — Cavities containing quartz crystals 

 are not uncommon, and in these we find the quartz often invested 

 by dolomite and pyrite crystals implanted on the dolomite. 

 These crystals are often in pyritohedral forms, whereas in the 

 reefs distinct crystals are not common, and in the country rock 

 they are most commonly cubes. Elsewhere (Dee River, Queens" 

 land) we have evidence of gold-nuggets moulded on quartz 

 crystals (7), but the large masses of gold found on the indicator 

 veins are commonly mixed with the vein quartz. 



We find, however, evidence of dolomite preceding quartz as 

 well as following it, and pyrite is found enclosed both in quartz 

 and in dolomite. 



Cry.stals of arsenopyrite are found in the country rock at Mt. 

 Pleasant, Ballarat, invested by a thin layer of quartz. 



Commonly no growth lines in the quartz are detected nor any 

 crustified character in the reefs. The laminations of the reefs 

 often noticed may be referred to the disposition of the quartz 

 along a series of sub-parallel cracks in the original rock, or in a 

 fault-rock, and the formation of mullocky reefs may be ascribed 

 similarly to deposition on numerous cracks traversing shattered 

 rocks. 



We may regard as original the carbonaceous matter of the 

 laminations and probably the grey gi-anular dolomite bands such 



