450 



varying nature of the subsidence is shown by the alternation 

 of sands, clays, and lignites in the leads and the fact that 

 the basalts of the Newer Volcanics were poured out during 

 the sinking movement, is shown by the occurrence of 

 basalt flows both above and between the "lead" deposits 



Age of the Leads of the "Xetrcr \'<>le<t h/c.s."— The age 

 of these continental deposits has been given as Upper 

 Pliocene by such eminent authorities as McCoy, von 

 Mueller and Murray, because of the position they occupy 

 with respect to certain marine strata supposed to be Upper 

 Pliocene, and also because of their superior position to 

 certain so called Miocene marine beds. As stated in a 

 previous chapter, there appears to be some conflict of 

 opinion among Victorian biologists as to the exact age of 

 certain marine beds of Tertiary age which are inferior to 

 the "leads." Under these circumstances it may be advis- 

 able to institute a physiographic comparison lietvveen the 

 Pliocene and Pleistocene corrasive activities in North 

 America on the one hand, and the work supposed to have 

 been accomplished in Kasteru Australia in similar periods 

 on the other hand. In this way some light may be thrown 

 on the problem of the age of the " Newer Volcanics " and 

 their subjacent "Leads." 



In Eastern Australia we have evidence of a moderately 

 raised peneplain, on whose surface deep "leads" were 

 formed during a later subsidence. Basalts then deluged 

 this area, and still later, stream activities dismantled the 

 great basalt flows and induced sets of very broad shallow 

 valleys in them. Then came the great revolution in the 



were heavily faulted and Hexed, and later still the profound 

 canons of Eastern Australia were formed. 



