GEOLOGY OF NORTH GIPPSLAND, VICTORIA. 23 
oe the Native-Dog Creek, to the Toonginbooka River, or to the Little 
iver. 
Many of the agglomerates are extremely interesting. They are 
formed entirely of angular or slightly rounded fragments, varieties 
of felstone, or of quartz-porphyries, and with, in some instances, 
fragments of granite; these fragments are of all sizes from almost 
dust up to several fect in diameter. When the base is light in hue, 
or dark red, the contrast to the variously coloured and textured 
fragments is striking. Generally, however, the weathered surfaces 
are dull, and only show the fragments standing out in relief. 
The whole of these rock masses have evidently been subject to 
great changes; they are almost universally quartziferous, the quartz 
being more or less perfectly crystallized in double pyramids ; and I 
suspect that a great part of the apparent felstones is merely altered 
silicified ash. 
The general series of this formation, as seen in the deep gorge of 
the Little River, may be about 2000 feet ; the stream has cut a con- 
stant succession of falls in its rock-bound chasm. ‘The lowest rocks 
visible are allied to the quartz-porphyries with occasional agelome- 
rates; in the upper parts there are agglomerates, ash, and felstones, 
all much consolidated and siliceous, and penetrated by irregular 
branching veins and dykes of hard white felstone. In this gorge 
I found some of the beds of coarse ash beautifully distinguished 
from each other, not only by marked planes of deposit, but by the 
different texture of the beds themselves. The whole of the series 
appears to be of subaerial origin. 
All these considerations have led me to believe that in the Wom- 
bargo Mountain we may recognize the site of a Paleeozoic voleano, 
the central mountain being the denuded core round which some 
small portions of the vast masses of ejectamenta still remain 
grouped. 
The Cobboras, St. Pancras Peak, Mt. Statham, may be indicated 
as presenting quite similar appearances to those of Wombargo, and 
taken together may possibly represent a somewhat north and south 
line of volcanic orifices extending southward through the Buchan 
country. The isolated mountains which I have mentioned as stand- 
ing in the Marine Tertiary area convey to my mind a strong sugges- 
tion of similar origin and similar age. Such are Mount Taylor and 
Mount Nowa Nowa, in the neighbourhood of each of which the 
Tertiary gravels are largely composed of felstones and other igneous 
rocks belonging to the “ Snowy-River Porphyries.” 
The relative proportions, as given in the sketch section, of the central] 
quartz-porphyry and the surrounding felstones, are no doubt quite 
conjectural, and the former I believe to be far in excess of the truth. 
I merely wished to indicate as nearly as possible the general genetic 
relations, as I believe them to be, of these most interesting rock 
masses. 
(e) Middle Devonian.—I have already pointed out that the an- 
cient volcanic materials of the Snowy-River country rest upon the 
Silurian, and are overlain by Middle-Devonian marine beds. On 
