172 Frederick Chapman: 



only be arrived at by a careful search of valley sections in those 

 areas, for evidence of silicilied tree-stems in situ. 



With regard to the silicification of loose sand overlain by basalt, 

 it is, for example, well known that the sands of'Kalimnan age in 

 the Melbourne area which would otherwise be of loose texture, where 

 covered by the newer basalt, are consolidated and silicified, it 

 may be assumed, by alkaline waters from the overlying lavas, 

 which either contained dissolved silica or dissolved it during 

 percolation; and frequently pieces of wood are found in the sands 

 which have been preserved through the reactions from the lava 

 above. It is therefore easy to conceive that in the same way the 

 thorough silicification of logs of wood might occur in the Miocene 

 deposits of the uplands and plateaus of Gippsland, where leaves 

 of Eucalypts and fronds of ferns have been found, as at Dargo and 

 Bogong. 



Up to the present no information regarding the occurrence of 

 silicified wood in the Dargo district has been furnished, the wood 

 there found being merely lignified. Thus, Reginald A. F. Mur- 

 ray, in his " Report on the Geological Survey of Portions of Dargo 

 ■and Bogong,"! mentions gravels, sands and clays with impure 

 lignites of Miocene age, resting on the bedrock and overlain by 

 Miocene basalt (op. cit. p. 98). The same author (p. 102) says, 

 " In a head of the Bundarrah, on the south-western margin of the 

 l>asalt, are exposed beds of yellowish brown laminar clay contain- 

 ing fossil leaves"; and again (p. 106), referring to the beds ex- 

 posed on the Mayford Spur at Synnot's claim, he states that '' here 

 also are siliceous conglomerates and ferruginous bands containing 

 fossil leaves." 



Description of Fossil Wood. 



Specimen A. Eucalyptus aff. melliodora, Cunningham. 



This specimen is a slab of silicified wood measuring about 15 

 cm. X 9 cm. x 3 cm. It was presented to the Museum collection by 

 Mr. G. S. Rees, of the Construction Branch of the Victorian Rail- 

 ways, and was obtained by Malcolm S. Moore, B.E., in 1915, from 

 Bruthen, during the construction of the Orbost railway line. The 

 following is a note on its occurrence kindly supplied by Mr. Moore 

 at my request : — 



1 Prog. Rep. Geol. Surv. Vict., No. V., 1878, pp. 96-117. 



