42 
Geology and Physical Geography 
Some of the higher mountains rising from the general level of 
the table-land are marked by central masses of quartz-porphyry 
of a distinctive character from the bulk of the Snowy River 
porphyries. 
In the north, the Cobberas, the Wombargo Mountain, and the- 
range thence northward to Mount Hotham, and in the south, 
Mount Tara and Mount Nowa Now a belong to this class. The 
general conclusions arrived at by Mr. Howittaro, to quote his own 
Fig. 9.— Near Mcrrindal River. 
(d) Very fine-drained rock— felspathic 
dark to light purple, in alternating band* 
of colour. Throughout the fine-grained 
rock there are patches of coarse particles. 
The dip is probably N. 10°-20° E. at 53°. 
09 Similar fine-grained rock, with coarse 
fragments imbedded. 
(b) Fine-grained rock, grey in colour ; 
under the lens particles can bo made out 
which are angular— some seem to be 
minute prisms of felspar. 
00 Agglomerate of varieties of fel* 
stones, from 12 inches diameter to dust. 
The surface weathers very rough. 
words, that — “The Snowy River porphyries may bo regarded 
as a great volcanic sheet, the lowest part of which is seen in the 
Little River and the upper part at the Wombargo uplands. It 
rests upon the Lower Palaeozoic foundation, and in places has been 
let down by faults into it. Its lowest portions approach the 
quartz-porphyries in character, and in ascending it becomes more 
and more fragmentary.” 
In a portion of the district “ these great masses of felspathic 
rocks seem to lie grouped around a central mass of quartz-por- 
phyries of a somewhat peculiar character.” Mr. Ilowitt proceeds 
to draw “the inference that in the Snowy River porphyries we 
may see the accumulations of ash, agglomerates, and lavas, due to 
former volcanic activity in Palaeozoic times,” and that “ these 
rocks, whose characters are obscure, may well be regarded as 
having undergone such changes that former beds of fine ash, or 
even of agglomerates, may have become structureless rock -masses 
of siliceous and felsitic character.” 
Tho ridge extending from the Cobberas to near Buchan, along 
which occur the masses of quartz-porphyries, is regarded by Mr. 
Ilowitt as indicating the line of “ a meridional fissure on which a 
series of volcanoes was built up/* and the masses of quartz- 
porphyry as the “denuded stumps of volcanoes round which 
d — 
c— 10 ft. 
6—20 ft. 
a— 5 ft. 
