130 



On the west, between Blakiston Church and "Wyn- 

 yard," the residence of Rev. J. Gower, the rocks are actinolite 

 schists of various types. The knoll upon which Wynyard 

 stands is composed of the purplish rock which I have else- 

 where designated soapstone, and has furnished the build- 

 ing stone for the house. Exactly similar rock, also used as 

 a building stone, occurs about half a mile south of Nairne 

 Station. We then have a series of solid quartzites, which 

 make strong outcrops. These give place to soft, very dark 

 schists, which have worn down to form the bed of the creek. 

 On the actual line of section there is no sign of marble, 

 but less than a mile to the south there is a very strong out- 

 crop of very coarse crystalline limestone like that of Angas- 

 ton, I have, therefore, included it in the section. East of 

 the limestone belt we have dark schists in which light spots 

 begin to appear. These spots increase in size and abund- 

 ance, and the rock passes into typical paringite. In- 

 truded along the bedding planes of these schists is a narrow 

 dyke or sill of coarse pegmatite. Eastward the paringite 

 gives place to a great thickness of quartzites. These are for 

 the most part flaggy in structure, though the huge mass 

 of Mount Barker is as solid as the great belt of quartzite at 

 Mitcham and Burnside, near Adelaide. 



Sum7}Tary of Geological Descriptions. — East of the Onka- 

 paringa there exists an immense thickness of crystalline 

 schists of a variety of types. These have pretty uniformly 

 high dips between east or south-east, and there are few in- 

 stances of reversal of these dips. These facts led Professor 

 Tate to the conclusion that the schists formed the upper 

 portion of a continuous series many thousands of feet in 

 thickness, and building the Mount Lofty Ranges. Their age 

 he believed to be pre-Cambrian. It has been shown by Mr. 

 Howchin that the western part of this series is lower Cam- 

 brian, and the same observer has proved the existence of a 

 basal conglomerate to this system resting unconformably on 

 pre-Cambrian rocks near Aldgate and other places. The 

 general conformity in dip throughout the Mount Lofty Ranges 

 is very misleading. 



The rocks of the schist series east of the Onkaparinga 

 are lithologically much more highly metamorphosed than 

 those of the lower Cambrian, and though stratigraphical data 

 are, as yet, incomplete, there is little doubt that Professor 

 Tate was right in classing' them as pre-Cambrian. 



It is probable that they do not form a continuous series 

 for the whole distance, some thirty miles, between the Onka- 

 paringa and the Murray, but that the beds have been re- 

 peated by strike faulting and by heavy folding. Certain 



