Geology of Mooroodnc. Ul 



acid dykos which penetrate the sediuientaiy rocks in a c[uarry 

 north of Mooroodue Railway Station. He notes that they have 

 indurated the contiguous strata for distances ranging from less 

 than an inch to several feet. He describes 'ino>t of the dykes as 

 aplites, and makes the interesting observation that the musco- 

 vite and biotite in the dykes line the walls, while the centres 

 consist of the more acid quartz and felspiw. He gives a litho- 

 logica/l description of the sediments, and refers to the spotted 

 character of the thin bedded micaceous shales. The rocks are 

 described under the heading "Silurian" by Mr. Kitson, and 

 the same view is expres-sed in the large Geological Map of 

 Victoria of 1902. Mr. Kitson, however, remarks that the rocks 

 resemble in some respects the gi-aptolite^bearing shales of the 

 Lancefield district, and "' they may eventually prove to be of 

 Ordovician age, though the Silurian belt may be the exten- 

 sion of the Upper Silurian of the Melbourne district." 



In the year 1900, Mr. Evelyn Hogg published a paper en- 

 titled, "The Petrology of certain Victorian gi'anites." i. Mr. 

 Hogg does not discuss the granitic rock at Mt. Eliza, but 

 describes one from an adjoining locality, Frankston, as a 

 medium-grained graiiitite, a rock with pink felspar, orthoclase and 

 plagioclase being about equally represented, quartz and biotite. 

 The rock of Watson's Quarry, Mt. Martha, lying south of Mt. 

 Eliza, is described as a medium-gi'ained syenite. As these are 

 the nearest granitic masses to Mt. Eliza, their composition is of 

 some interest in this connection. It is to be noted, however, 

 that Mr. Hogg defines a granitite as including all holocrystalline 

 quartz-biotite, rocks in which a mouoclinic felspar is not the 

 dominant one, while he defines a syenite as a normal gi'anite 

 with hornblende. Most j^e-trologists would now, I think, describe 

 such a rock as a hornblende gi'anite. 



In 1901, Messrs. T. S. Hall and G. B. Pritchard published a 

 paperiuthe Proceedingsof theRoyal Society of Victoria, Vol. XIV., 

 N.S,. Pt. 1, entitled " Some Sections Illustrating the Geological 

 Structure of the Country about Morniugton." They go fully into 

 the previous literature of the area, and the greater part of the 

 paper is devoted to the detailed discussion of the Tertiary r(n-ks 

 and fossils of the district. The rocks of the Mooroodue quarry 



1 Proc. Roy. Soc. Vic-t., n.a., vol. xiii., 1900, p. 21S. 



