127 



that described above (p. 122). It is to be noted that a 

 similar rock occurs in a railway cutting between Balhannah 

 and Ambleside. We cannot at present correlate these occur- 

 rences. It is quite possible that they are quite independent, 

 but the lithological characters are so peculiar and so strik- 

 ingly similar that they are worthy of careful study. Two 

 other exposures which should be compared with those above 

 noted are, the steep bluff forming the right bank of the 

 Onkaparinga close to Ambleside Station, and the long road 

 cutting about a mile from Forest Range, on the Lobethal 

 road. Typical mica schists continue for some distance past 

 Dawesley. About a mile past the bridge over Scott's Creek, 

 and just past a little chapel on top of the hill, there is ano- 

 ther splendid exposure of paringite. This must be directly 

 connected with the exposure at the type locality on the rail- 

 way line (p. 123). The connection has not been mapped in. 



From this point to Callington the road traverses the 

 schists in a direction not departing widely from their strike; 

 the variety of rock types is, therefore, not great. There is 

 a general tendency towards increasing metamorphism, with 

 extensive development of muscovite. This mineral is often in 

 porphyritic crystals lying across the schistosity. 



Shortly after passing Kanmantoo a very perfect S-shaped 

 fold is visible on the hill slope, about a quarter of a mile 

 west of the road. Close to Callington the schists are much 

 shattered and injected with quartz veins. Some of these 

 veins are slightly felspathic, showing that they represent the 

 limiting members of a series of pegmatite dykes. 



From Callington to Murray Bridge the road follows the 

 railway line so closely that there is practically no difference 

 between the sections they reveal. The width of the Monarto 

 granite belt is practically the same on the road as it is on 

 the railway. 



On the right bank of the river at Murray Bridge a few 

 outcrops of granite occur. This rock is quite different in 

 character from the Monarto granite. It has not been sectioned, 

 as all the exposures are too rotten. The rock is reddish in 

 colour, more coarsely crystalline, and much more gneissic 

 in texture than the Monarto rock. It contains fairly large 

 pink phenocrysts of orthoclase. 



Another very instructive road section is seen between 

 Callington and Mount Barker Town, via the Bremer road. 

 For the first four and a half miles from Callington the road 

 (to Strathalbyn) following the Bremer River runs prac- 

 tically along the strike of the beds, so that very little variety 

 is met with. Muscovite schists, like those noted above, are 

 the chief types. It is extremely difficult to obtain readings 



