144 THE VICTORIAN NATURALIST. 



CORRESPONDENCE. 



The Geology of the You Yangs. 

 To the Editor of the Victorian Naturalist. 

 Sir, — In the account of the excursion of some of the mem- 

 bers of the Field Naturahsts' Club to the You Yangs in the 

 December number of the journal I read the following : — 



1. "The rugged nature of these miniature mountains became 

 more apparent as we approached, the immense granite boulders 

 being very conspicuous." 



2. "The plains, which are principally of upper volcanic 

 formation, are almost treeless, but became partially wooded 

 with she-oaks, honeysuckles, and stringybarks on the newer 

 pliocene which surrounds the granite mountains." 



Here, it is plain to my mind that the writer has strangely 

 enough confounded detached weathered masses of the coarse 

 porphyritic granite composing the so-called mountains and the 

 weathered masses or bosses of the same rock appearing in situ, 

 with transported, erratic, and rounded blocks, which constitute 

 the true boulders of the geologist. As one of the party, and as 

 a geological observer, I failed to detect the slightest evidence 

 of either glaciation or the transportation of rock-masses by 

 aqueous agency, while the progress reports and sketch maps of 

 the Government survey fail to indicate their occurrence. I need 

 scarcely observe that the existence of such boulders would, 

 at the present time, when so many practical geologic observers 

 and theorists contend so strenuously for the existence of 

 evidence of past glaciation in Australia, be of immense interest 

 and importance. 



Equally untenable with the foregoing statement is that of 

 newer pliocene deposits immediately surrounding the granite 

 hills. There was no evidence that I could detect of any deposit 

 older than the Quaternary, consisting of humus and its usually 

 associated aeolian sand-stratum, occurring with a thin deposit of 

 arenaceous brownish-yellow clay, which, apparently, super- 

 imposes the basaltic lava of the Werribee Plain. If any 

 paleontological evidence of newer pliocene age was obtained, 

 that evidence was not laid before the members of the Club. It 

 would seem, from all the accumulated data at my command, 

 that there are no newer pliocene deposits nearer to these granite 

 hills than a short distance inland from Corio Bay, in the direc- 

 tion of Geelong, some miles distant. With all due respect — 

 based upon such brief observation as circumstances would 

 permit, I should describe the geology of the country in the 

 immediate vicinity of the granite hills in question as consisting 

 of Quaternary deposits, interrupted at intervals by protrusions 

 of basaltic lava. — I am, &c., S. H. Wintle. 



