290 K R Junner: 



pebbles are not numerous. Others of vein quartz, sandstone, slate, 

 limestone and rarely chert were found by the writer. These 

 pebbles are usually small and rounded. Some of them are well 

 jointed by planes perpendicular to their longest axes, and these 

 joint planes are occasionally covered with a film of pyrites. Un- 

 •doubtedly this conglomerate, like the one near Cooper's Creek, 

 is a normal marine shore line deposit. 



The author saw no evidence anywhere of the immense fault re- 

 ferred to by Mr. Stirling, and he feels convinced that no such 

 fault exists. No slickensides or gouges were seen ; and the shape 

 •of the pebbles does not support the view that they have originated 

 by faulting. No great disturbance of the strata has taken place, 

 and there is no evidence of any displacement of the beds. Thei 

 petrological characters of these pebbles disprove of the idea that they 

 were formed by the brecciation of the associated dyke, referred 

 to by Mr. Stirling, and forcibly suggest that they were derived 

 from pre Upper Silurian igneous rocks. The only series of vol- 

 canic rocks in Victoria, known to be pre Silurian in age, are 

 the Heathcotian, and hornblende diabase and associated pyro- 

 clastic rocks are characteristic of this series. The pebbles of 

 gneiss in the conglomerate must, undoubtedly, have come from the 

 pre Cambrian metamorphics of eastern Victoria, and the large 

 felspar crystals, referred to by Mr. Stirlingl, may have come from 

 the same source. 



Further, Mr. Stirling's strong point of the occurrence of the 

 breccia first, on the east side of the limestone near the Copper 

 Mine township, and on the west side of it further south, can be 

 explained away when it is recognised that the limestone bands 

 are lenticular, and are not persistent in strike, and that there 

 may be two or more lenticular patches of limestone not quite on 

 the same line of strike. 



Moreover, tlie evidence at hand does not support Mr. Chap- 

 man's belief in contemporaneous andesitic vulcanicity. It seems 

 to me more probable, as Professor Skeats2 has suggested, that the 

 volcanic debris included in the limestones, is detrital. The as- 

 sociated conglomerates and grits contain abundant, undoubtedly 

 •detrital, igneous pebbles, and it is quite natural to expect that 

 some of this material should be deposited with the limestones. The 

 field relations do not lend any support to Mr. Chapman's sugges- 



1 Op. cit. 



2 "The Volcanic Rock of Victoria." Pres. Add., Sect. C, .\iis. Assoc. Adv. Sci., I90». 



