so Proceedings of the Royal Society of Vict07'ia. 



with its gravels is left in what is, at first sight, an inexplicable 

 position. Since he wrote, the subject has received considerable 

 attention in the United States.* 



The officers of the Survey have devoted a great amount of cai*e 

 to these economically valuable beds,t and have divided the 

 gravels of this district into older and newer pliocene and recent. 

 The evidence of the separation of the first two named, is 

 frequently very obscure. I do not see, for instance, how the 

 lower portion of the Forty-foot Hill deposit is classed as of the 

 same age as that capping Diamond Hill, lower down the same 

 stream and about eighty feet higher above sea level. The 

 character of the deposits is described in the greatest detail by 

 U Irich, and it will suffice to state that all the rocks in the gravels 

 accur in situ in the present water-shed, there being a prepon- 

 derance of those found near the granite boundary. The indu- 

 rating action of metamorphism is shown both by the range 

 bounding the granite and by the occurrence of fragments many 

 miles below the metamorphic zone. Slickensided fragments 

 frequently occur, but I have not seen any examples of which could 

 be referred to glacial action. Some terrestrial fossils are recorded 

 on the Southern Maldon sheet from these older gravels. Amongst 

 other specimens was an almost complete skull of Sarcophilus 

 ur sinus. The only organic remains I have found are a few traces 

 of plants which were, however, quite indeterminate. 



Volcanic Rocks. 



Dykes of basic volcanic rock are fairly common, though very 

 few are shown on the map, their small size and decomposed 

 condition rendering their detection at the surface almost, if not 

 quite, impossible. The rock contains numerous crystals of olivene 

 and hornblende, frequently of large size. Black mica occurs in a 

 dyke at the Eureka Reef and in one near Harcourt, at the latter 

 place sometimes reaching three-quarter inch in diameter. | One 

 dyke, six feet tliick, at Burns' Reef, is traceable north for more 

 than a mile; others occur on the west side of Wattle Gully, at 

 the Englishman's Reef, Ajax Mine, while several are exposed in 



* Contributious to "Science," 1893, &c. 



t Ulrich— Cat. Rocks, &c., p. 189, et seq., ami repriuted iu Lock's Practical Gold ilining. 



t See also L'lricli, loc. cit., p. 35. 



