INAUGURAL ADDRESS. 47 



of these metaniorphic rocks is Archaean. Resemblances in mineral 

 character are at their best very unsafe guides, and we have in this 

 instance an actual betrayal into a most serious error as a result of 

 trusting in them. 



Selwyn* placed the metaniorphic rocks of the extreme western 

 limits of Victoria as " possibly a true Cambrian or Azoic series." 

 And again, " perhaps the rocks of some of the larger areas mapped 

 as metamorphic repi'esent Cambrian or Laurentian series. "f 



Jukes;]: says it is highly probable that the gneiss and mica 

 schists which form the mountain chains of Australia belong wholly 

 or in part to the Pre-Cambrian periods, and this affords another 

 instance of the marvellous geological instinct possessed by this able 

 geologist. 



Geikie, A§., referring to the opinion of Selwyn and others that 

 the crystalline schists are metamorphosed Palaeozoic formations, 

 adds, " but there are not improbably other areas referable to an 

 Archaean series." 



Hakdman II provisionally classed as Lower Silurian or Cambro- 

 Silurian the metamorphic rocks of the Kimberley district, W.A., 

 but adds that ''it is not improbable that these rocks, as well as 

 similar formations in this colony and the other Australian colonies, 

 may be of Laurentian age." 



Clarke^ was of the opinion that there is not sufficient evidence 

 that Azoic rocks exist in East Australia, and that some of the 

 gneiss so placed by Strzelecki are merely products of transmutation. 



Aplin considered the granite of Severn River, Queensland, as 

 of metamorphic origin, quoted by Daintree.** 



It is only in South Australia and West Australia that the 

 metamorphic rocks are actually known to be Pre-Cambrian, 

 but those elsewhere, unless they can be shown to be transmuted 

 Palaeozoic rocks, may be most conveniently referred to the same 

 period. 



The grandest exemplification of the Archaeans is in the Mount 

 Lofty Range of South Australia. These rocks occupy there a vast 

 monocline, with a dip to the south-east, of not less than ten miles in 

 thickness. One noteworthy lithological feature is the more highly 

 developed metamorphism of the upper strata, mica schist, gneiss, 

 and granite, succeeding in an ascending series clay slates, 

 quartzites, and limestones. This exceptional phenomenon was 



• Exhibition Essays, 1861. t Cat. Rocks, National Museum, 18G8, p. 33. 



t Manual Geology, 2nd edit., p. 434, 1862. ? Text-book of Geology, p, 640, 1882. 



il W.A. Pari. Paper, Geol. Kimberley District, 1884, p. 6. 



•I International Exhib. Essays, 1867, p. 381. •* Quart. Journ. Geol. See, 1872, vol. xxviii. 



