]28 PROCEEDINGS OP THE ROYAL SOCIETY OF QUEENSLAND. 



preponderance of biotite and the specific gravity were 

 factors in common with the Pink Phase. 



Table 1, 



This rock, as the result of the opening of new quarries, 

 has proved to be considerably more extensive than the 

 author first thought. If, as its mineralogical contents and 

 chemical composition both suggest, it is related to both 

 phases, there are onl}^ three possible modes of origin — 



(1.) That it is the parent magma from which both 

 the Pink and Grey Phases sprang ; 



(2.) That it is an intermediate member of a series 

 E1-E2-E4, thus linking the two phases; or 



(3.) That it is the result of admixture of the Pink 

 and the Grey Phases. 

 The first idea that it may represent part of the parent 

 magma or undifferentiated portion is refuted by the 

 evidence as to the two main magmatic series in Southern 

 Queensland, to be discussed more fully later in the paper. 

 Further, in the light of modern petrology we can hardly 

 postulate the splitting of such a magma as that represented 



