136 Robert A. Kehle : 



sedimentary series, and massifs of almost equally resistant dacite, 

 also of Palaeozoic age. The Older Basalt and Newer Basalt are of 

 Tertiary age. 



If the large stream^ that flowed in the vicinity of Klingsporn's 

 Station,^ Wood's Point, Mt. Leckie, Drouin, Lang Lang, French 

 Island, Flinders and Cape Shanck had its source at Mount BuUer 

 .and its outlet somewhere near Flinders Island in Bass Strait, as 

 the bathymetrical contours would suggest, only its headwaters are 

 represented in the 130 miles now above sea level. The most moun- 

 tainous part of its course was between Mt. BuUer and Drouin, and 

 in the vicinity of Flinders. Bearing in mind that the mature 

 erosion of a mountain region, which a reconstruction of the residuals 

 appears to suggest, is characterised by steep declivities rising some- 

 times thousands of feet above the flood plain, one may comprehend 

 much that seems unusual from the two thousand feet of lava 

 assumed to have existed at Flinders from the evidence of a bore, 

 and the amount of denudation disclosed by the slope above it. 

 Perhaps the valleys of the Kiewa, Buckland, and other streams in 

 the north-east province of Victoria are comparable to the Pre- 

 Older Basalt stream just mentioned; they are typical examples of 

 erosion in a mountain region ; and meander over well graded flood 

 plains. 



The erosion of the Port Phillip system during the Pre-Older 

 Basalt cycle was affected by different considerations. There were 

 no dacite massifs, and the contact metamorphic rocks were so 

 disposed that large areas of the less resistant rocks permitted a 

 rapid development of the stream system. 



Western Port and Port Phillip lava fields. 



With da'-a forthcoming from the sections of residuals (Fig. 4), 

 their configuration (Fig. 9), disposition, and the trend of " un- 

 covered residuals, "3 a reconstruction of the surface of the Western 

 Port and Port Phillip lava fields is possible. This reconstruction 

 {Fig. 4) sliows that at the cessation of volcanic activity the valleys 

 of the Pre-Older Basalt cycle were occupied in their upper portions 

 by long tongues of lava (confined lava fields), which merged south- 

 wards into a more extensive plain (extensive lava field). South of 



1 Ostensibly. Prof. Grejrory's Tarngo, vide Bibliog., No. 4. 



2 Klincsporn's Station is situated south-west of Mount Buller, between the Howqua and 

 Jamieson Rivers. The area of older Basalt representing: the residual has never been charted. 



3 Vide p. 147, post et fig. 8. 



