341 



metamorphism had already been effected prior to intrusion. 

 This is in harmony with the view that regional metamorphism 

 had been induced in the period of maximum intensity of fold- 

 ing, and that the igneous intrusions, while directly related to 

 the orogenic movements, were developed at the close of the 

 folding period, when movement was of a broad and relatively 

 simple type. 



The mass of Cape Willoughby is to be correlated — based 

 on the observations of Mr. W. R. Browne, B.Sc, detailed in 

 a forthcoming paper — with the granite masses of Victor 

 Harbour and Port Elliot, both on field and petrological 

 evidence. 



Conclusion. 



In conclusion the writer would suggest that : — 

 (i.) The masses of Cape Willoughby, Victor Harbour, 

 and Port Elliot represent chonolitic masses of 

 limited surface extent, which are connected at 

 depth to a single batholitic chamber, 

 (ii.) These chonolites are arranged along a zone parallel 

 to the strike direction of the older Palaeozoic 

 folding. 



(iii.) These chonolitic intrusions, whilst related to the 

 orogenic movements, were developed only at the 

 close of the folding epoch, when movements were 

 of a comparatively broad and simple type. 



The writer is indebted to Mr. W. R. Browne, B.Sc, for 

 much help and advice during the preparation of this paper. 



DESCRIPTION OF PLATES. 



Plate XXX. 



View of granite outcrop forming part of the Cape Willoughby 

 headland. 



Plate XXXI. 



Fig. 1. Sagenite web of rutile in quartz albitite. Magn., 

 50 diams. 



Fig. 2. A typical section of chequer structure in albite of the 

 albitites. Magn., 53 diams. + nicols. 



