424 E. C. ANDREWS. 



Use of analogical method.— An example is here given of 

 the application of the analogical method to problems of late 

 and post Ten hi vy ag<- in Kash-ra A ust t alia when the palaeon- 

 tologies! criteria of age available are not conclusive. 



(a) From Thursday Island on the north to the south- 

 west of Victoria, a warped and faulted plateau surface 

 may be traced apparently parallel to the shore line. This 

 irregular surface was once continuous. It is now diver- 

 sified with wide shallow valleys, along which profound 

 canons are receding, the canon streams themselves having 

 been rejuvenated on several occasions. On the high-level 

 surface also lie numerous "Deep Leads" or buried river 

 channels. The greatest irregularities, or block faultings, 

 of the plateau occur in the knot of the Australian Alps 

 formed at the angle where the plateau of Eastern Australia 

 swings from an eastern to a northern direction, the whole 

 making a magnificent arc convex to the Pacific. The 

 eastern slope of this plateau descends more rapidly to the 

 Pacific by faultings and warpings than does the western 

 slope to the inland plains, with the exception of the western 

 fall of the Australian Alps, which in turn break away more 

 rapidly inland than to the ocean. 



(b) The topography of the western side of the United 

 States is similar in a general way to that of Eastern Aus- 

 tralia, the elevation, the block faulting, and the dissection 

 of the North American area being on a grander scale, 

 however, than that of Australia. "Valley in valley" 

 appearance is also characteristic of the American valleys. 



(c) The peneplanation of Western America has been 

 generally assigned to Tertiary activities. The Pliocene 

 has been considered as the period during which the exca- 

 vation of excessively broad valleys (incipient peneplains) 

 took place, while the plateau-forming period, the block- 

 faulting, and the formation of such gorges as those of the 



