148 ENOGGERA GRANITE AND ALLIED INTRUSIVES. 



separated by recent allu\dum merely, and there is 

 every reason for considering them as parts of one common 

 mass with its major axis approximately meridional, and 

 about one and a-quarter miles in length. 



If the major axis of the Enoggera Area be continued 

 to the south, it will be seen to pass through the centre of the 

 smaller Green Hill outcrop. Thus this direction maj^ be 

 considered a true axis of igneous intrusion. The Kedron 

 Brook outcrops are so seldom seen in direct contact with, 

 the intruded schist that only a rough idea can be gained 

 as to the real shape of the body, but as has been suggested, 

 it. too, is probably roughly meridional. 



Thus we see that, like the great granite batholiths of 

 New England,! the axis of intrusion of the Enoggera 

 granites differs from the strike of the older country rock, — 

 which in both cases is almost certainly the result of folding 

 in Permo-Carboniferous times — and seems to sympathise 

 with the trend of the adjacent coast line. Further north, 

 in Central Queensland, where the coast line takes the same 

 direction as the prevailing strike of the older rocks, the 

 granite batholiths too have this direction.^ This suggests 

 that in Queensland — or at least in Southern Queensland — 

 the axes of intrusion belong — as in the case of New South 

 Wales and Victoria^ — to those newer trend lines, which 

 were initiated soon after the Permo-Carboniferous folding, 

 and which ultimately determined the position of the present 

 coast line. 



Petrology * — The most marked feature of the granites 

 of the area is their variability. This is shown minera- 

 logically, in the nature of the constituent minerals and their 

 relative proportions, and texturally in the grainsize and 

 fabric of the rocks. In this peculiarity the granites resemble 

 very closely the first of the '" Later Granite Types " of 



1. T. W. E. David. Pres: Address to Roval Soe. of N.S.W, 

 1911, p. 36 



2. T. W. E. David, Pres. Address to Roval Soe. of N.S.W. 

 1911. p. 36. 



3. T. W. E. David, Pres. Address to Royal See. of N.S.W. 1911, 

 p. 36. 



* The Petrology of the igneous rocks of the area will be treated in 

 greater detail in Part II of this paper. 



