4 F. L. Stilhvell: 



phical allies of these rooks in Victoria, e.sx., the Kino^'s Quarry rnck 

 at Macedon (11), have resulted in very small flows, and any small flow 

 at Bendigo could well have been denuded away. 



Petrology. 



( lieiniral Chnrarferx. 



A rock sample from the Central Red, White and Blue Mine, Sheeps- 

 head line, was analysed. This samiple was taken from the thicker of 

 the two lavas which occur within a, few feet of each other in a small 

 crosscut at the 318-foot level. This rock was chosen because it was 

 found to be very fresh. The analysis made is in general similar to that 

 made by Mr. Frank Stone, quoted in Dr. Hewitt's paper (3), of a sample 

 of the New Chum lava in Lansell's 180 Mine. 



100.47 99.20 



i. Dyke, Central Red, White and IMue Mine, Sheepshead line. 

 Analyst, F. Stillwell. 



IT. Dyke, Lan-sell's 180 Mine, New Chum line. Analyst, F. Stone 

 The Sheepshead line is immediately east of the New Chum line, and 

 these analyses tend to emphasise the minor variations that can he noted 

 microscopically in various samples of the Bendigo monchicpiites. The 

 Sheepshead lava is relatively more acid, though at the same time it is 

 a fresher rock. The high titanium content tinds expression in the 

 highly titaniferous augite, and the abundance of ilmenite. Tlie low 

 silica percentage, moderately low alumina, moderately high alkalies 

 with soda predominating over potash, high lime, ferrous irtm and 

 magnesia are the chemical features of the monchicpiito group of rocks. 



