178 THE BUILDING OP EASTERN AUSTRALIA 



Professor Skeats has assigned to the Lower Devonian, 

 the dacite and quartz porphyrite series of Dandenong 

 Hills ; to the Middle Devonian, the felsite series of Buchan. 



Upper Paleozoic. 



To the Upper Devonian or Lower Carboniferous, 

 Professor Skeats has assigned great areas of rhyolite, quartz 

 porphyry and basalt at Mount Wellington, and in the 



Grampians. [25] 



Many of the N.S. Wales granite intrusions have been 

 referred to the Devonian, as have also many of the 

 granites of Southern Queensland. 



By far the most of the granites of N.S. Wales are con- 

 nected with the folding of the Devonian beds, and took 

 place prior to the deposition of the Upper Marine. The 

 granites of Yalwal, Sassafras, Narriga, Moruya, Moonbi 

 Ranges and many more, have proved to be post-Devonian 

 and pre- Greta, and the probability is that they are all of 

 Carboniferous age. 



Carboniferous rhyolites occur associated with con- 

 glomerate formation to the west of the New England, 

 in the Nandewar Range. 



Melaphyres (basaltic) were at this time poured out 

 in the Avon River district of Victoria. 



The north-eastern portions of New South Wales were 

 still subsiding under a load of sediments, and the andesitic 

 eruptions of the Clarence town series were extruded over 

 the Stroud district and eastern New England. 



In the Per mo- Carboniferous period, the south coast 

 district of N.S. Wales was subjected to eruptions of Alkaline, 

 sub-alkaline and basic rocks. [26] These eruptions 

 initiated the period of uplift. 



Mesozoic. 



The chocolate shales of the Narrabeen series contain 

 volcanic minerals, and are probably to a great extent of 

 tuffaceous origin. 



Generally speaking, the Mesozoic period was in Eastern 

 Australia notable for the rareness of indications of volcanic 

 action. 



Some of the acid granites of the New England may 

 perhaps be of late Permo-Carb. or of early Mesozoic age. 



Some of the upper beds of the Clarence (Ipswich) 

 Series seem to have been tuffs. 



