Age of Auriferous Quartz Veins. 119 



contorted anywhere where I examined them ; the lower rocks are 

 much contorted ; quartz veins occur in the folded rocks, and 

 must have been deposited previous to the formation of the Upper 

 Silurian rocks. I may here word my position in this manner, 

 auriferous saddle reefs, and various forms of quartz deposits 

 occur associated with the folding of the Lower Silurian strata at 

 Bendigo and elsewhere. Payable gold has been found in the 

 recent gravels of the upper portions of Wombat Creek, where the 

 rocks are of Lower Silurian age, but lower down the creek where 

 the rocks are Upper Silurian no payable gold has been obtained. 

 Folded strata exist at Wombat Creek in the Lower Silurian 

 rocks, but not in those of the Upper Silurian which overlie them. 

 If any quartz veins exist which are connected with the folding 

 of the Lower Silurian rocks at Wombat Creek, gold from 

 portions of such reefs, etc., may now exist as "alluvial" gold in 

 the Upper Silurian conglomerate, which consists, in part, of the 

 detritus of the denuded Lower Silurian rocks. The Lower 

 Silurian rocks were contorted and denuded before the Upper 

 Silurian rocks were deposited upon them. It does not seem 

 probable that any tissures would long remain open, for if not 

 filled by some precipitated mineral or by a dyke, they would soon 

 be filled by particles of the country rocks scaling off the walls, 

 and a breccia would be formed. I consider it improbable that 

 fissures formed in the Lower Silurian period would remain open 

 and be filled by quartz in any subsequent period. Generally 

 speaking, schistoze rocks are very rare in our Upper Silurian 

 strata, but are abundant in those of the Lower Silurian. At the 

 junction of micaceous and other schists with granite at various 

 places, notably Corryong, there are auriferous contact quartz 

 veins. I consider that these granitic intrusions took place, and 

 the associated quartz veins were formed prior to the formation 

 of the Upper Silurian strata. At Wombat Creek the Lower 

 Silurian rocks are metamorphosed, while the Upper are not. 

 The schistoze rocks of Corryong greatly resemble those of Wombat 

 Creek and between these places there is a general similarity in the 

 intervening metamorphic rocks, which appear to be Lower Silurian 

 strata more or less altered. Within this metamorphic area the 

 unaltered Upper Silurian rocks occur, and I consider that the 

 formation of the auriferous reefs at Corryong was contempo- 



