392 REVIEWS 



to the axial planes of the folds, and to afford one of the prettiest keys 

 to the interpretation of the larger units of structure in areas of complexly 

 deformed rocks. 



The second half of the volume, upon geologic history, brings out the 

 fact that fewer geological systems are represented in South Australia 

 than in any other Australian state, for the reason that a few systems 

 cover a great extent of the country to the exclusion of the others. No 

 Silurian, Devonian, or Triassic beds have been recognized, and Eocene 

 beds have not as yet been definitely determined. 



Among the most important systems are the Cambrian and the 

 Permo-Carboniferous, in which occurred the very remarkable glaciations 

 for which South Australia has become famous. The Cretaceous beds 

 which surface a very considerable portion of South Australia form what 

 is believed to be the greatest artesian basin in the world, yielding an 

 abundant supply of usable water that is of the greatest economic im- 

 portance in the development of some of the driest parts of Australia. 

 These advantages, however, are shared with New South Wales, Queens- 

 land, and the Northern Territory. Following the discussion of each 

 period in South Australia is a brief description of that system in the 

 other Australian states. 



The illustrations are good, and the book should prove useful to the 

 working geologist outside of Australia as well as to the Australian student. 



R. T. C. 



