THE 



Transactions 



OF 



The Royal Society of South Australia. 



Vol. XXXIX. 



A Geological Sketch-Map, with descriptive Notes 



ON THE UPPER AND LOWER TO RRENS - LI M ESTON ES 

 IN THE TYPE DISTRICT. 



By Walter Howchin, F.G.S., Lecturer in Geology and 

 Palaeontology, University of Adelaide. 



[Read April 8, 1915.] 



With Map (Plate I.). 



The valley of the River Torrens, near the confluence of 

 the Sixth Creek, may be regarded as the type district for the 

 occurrence of the lower members of the Cambrian series. 

 There is less alluvial cover, and consequently less obscuration 

 of outcrops, in this locality than in most places where similar 

 beds occur. On the other hand, the disturbed condition of 

 the country makes it very difficult to follow and define the 

 respective beds, as their continuity is repeatedly broken by 

 faulting:, and the faulted segments are more or less displaced, 

 repeated, or obscured. Yet it is hoped that the geological 

 m.ap which accompanies this paper will be found, at least, 

 approximately correct. 



PRE-CAMBRIAN MASSIF. 



The township of Houghton is situated almost immediately 

 on the western boundaries of the Pre-Cambrian outcrops, and 



