556 president's address. 



a prolongation of the Tasmanian axes towards the N.W., nearly 

 at right angles. In the Macdonnell and Musgrave Ranges tiie 

 trend is E. and W., and in the Kimberley District of West Aus- 

 tralia N.W. and S.E., with a secondary folding S.W. and N.E. 



It is not certain whether, either in Australia or Tasmania, there 

 was any land surface in Archaean time, but the conglomerates in 

 the Archaean and in the succeeding Cambrian, and the ri})ple- 

 marked flaggy quartzites (if they are Archsean or Cambrian and 

 not Lower Silurian) imply shallow seas, with probably a neigh- 

 bouring land surface. It is improbable, too, that the Archaean 

 strata should have been as powerfully folded, as observation shows 

 them to have been, in Pre-Carabiian time, without some areas 

 being elevated sufficiently to form land. 



In Australia, therefore, there was probably land and probably 

 contem{)oraneous life, at all events in the seas, in Pre-Cambrian 

 time, the latter assumption being rendered probable by the occur- 

 rence of the beds of limestone and contemporaneous (?) iron ores 

 and graphite in the Archaean rocks of South Australia, and of 

 limestone and contemporaneous (I) ironstone in the Archsean rocks 

 of Tasmania, and also by the great diversity of forms of animal 

 life met with in the succeeding Lower Cambrian rocks. 



11. Cambrian. 



In South Australia Lower Cambrian rocks are now known to 

 exist at (1) Ardrossan, Parara, and Curramulka, in Yorke's Penin- 

 sula, on the west side of St. Vincent's Gulf, Wirrialpa, Blinman, 

 Kanaka, Parachillna, and near the Ajax Mine between Bel tana 

 and Leigh's Creek over 300 miles north of Adelaide. 



In the type district at Parara and Ardrossan in Yorke's Pen- 

 insula the Cambrian rocks, as described by Mr. Tepper, consist in 

 descending order of the Ardrossan sandstone showing false 

 bedding* occasionally coarse, and even passing into conglomerate. 

 Beneath it lie a variegated and dark limestone and white and 

 yellow marbles, dipping S. 27° E. at 15°. Below the marbles is a 



* Loc. cit. p. 76. 



