62 



"Whitlaw Gully, Section 7, Hundred of Nuriootpa, a deserted 

 drive, situated on the southern side of the gully, has been 

 extended into a similar heterogenous mass, a distance of from 

 20 to 30 feet. This adit penetrates the strata at an angle of 

 about 45° south-east to the line of strike. Though of little 

 or no mineralogic value, it is, nevertheless, interesting to the 

 geologist in so far as it exposes a rock section which otherwise 

 would have been concealed. 



On the western side of the eastern quartzite band laid down 

 on the map, and embraced in the sketch, a quartz vein, which 

 has several quartz leaders, intersects Sections 424, 425, and 

 426, and is well known to extend into Section 834. Here the 

 leaders, or quartz interlaminations, have been proved in the 

 Malcolm's Barossa Mine to contain copper and gold ; but up 

 to date neither of the metals has been found in payable quan- 

 tities. 



I may here remark that none of the Barossa quartz veins 

 has proved metalliferous in a high degree, and it is a note- 

 worthy fact that the quartzite band passing immediately to the 

 east of this mine and extending north and south many miles 

 throughout northern Para Wirraand southern Barossa at least is 

 the line of demarcation between the more highly metamorphosed 

 rocks on the eastern side and the less altered rocks on the 

 western side of the band. If accessive metamorphism be at all 

 conducive to the concentration of metallic deposits, then, as 

 metallic deposits are only sparingly distributed in the reefs on 

 the eastern side of the band where metamorphic agency has 

 been most potent, they will be still more sparingly distributed 

 on the western side where metamorphism has evidently been 

 much less active. 



MiOCEJfE. 



Superficial Area. — The dehris derived from this formation 

 constitutes most of the soils and subsoils immediately to the 

 east of Gawler and throughout the higher tracts in Concordia 

 District, and in the same detached condition it stretches south- 

 easterly into iipper Cockatoo Creek. Also the gravelly gold- 

 bearing cements of Yatta Creek, A^ictoria Hill, and neighbour- 

 hood, and on towards Williamstown belong to the same 

 geological epoch. Indubitable evidence still exists to show that 

 this formation, in a fragmentary state, extends to a height of 

 at least 1,000 feet above sea level, and that that portion of 

 Barossa Hundred, comprising the Barossa goldfields, Cockatoo 

 Creek, Lyndoch Valley, Concordia, and immediately to the 

 east of Gawler, was at one time uninterruptedly overlain with 

 Miocene strata. In the immediate neighbourhood of Gawler 

 its vertical thickness must have been something very consider- 



