578 
that constitute the plains. To the northward of Ballarat, portion of the Main Divide 
itself is of volcanic formation, and a wide sheet extending to the north, and finally dis- 
appearing under the Post-Tertiary deposits of the Loddon, covers the system of deep leads 
of Creswick, Clunes, and Daylesford, on their trend towards the Murray. At Ballarat 
there are four, and in other places two or three, distinct layers of basalt covering the leads. 
“The lowest overlie the deepest part of the gutters, and the next in succession 
spread more widely, till, as may now be seen, the uppermost lava-flow forms a wide 
sheet, covering not only the old rivers and their tributaries, but also most of the 
lower ridges of Silurian rock which sejjarate them. 
“ Throughout all the Newer Volcanic areas are found the points of eruption 
whence the lava streams issued, mammaloid or conical hills, in many of which well- 
formed crater-basins stiU exist, while in others the crateriform shape is still 
distinguishable, though the basin has been obliterated. Many of these extinct craters 
are now occupied by lakes or lagoons, as Tower Hill, near Warruambool, which has an 
insular peak rising from the centre of the lake; Mount Eels, and other crater basins in 
the western district, and Mount Mercer, south from Buninyong. Mounts Buninyong, 
Warrenheip, Pisgah, Eraiiklin, and numerous other volcanic hills 'in the Ballarat, 
Creswick, Daylesford, and other districts, are familiar instances of points of eruption 
where the outlines of the craters are still discernible. 
“ Around nearly all such points are scoriaceous lavas and volcanic ashes, among 
which are frequently found ejected masses of older rocks, from mere dust up to several 
tons in weight. 
“ For instance, in the volcanic ash of the Anakies, near Greelong, are found 
ejected blocks of granite. At Buninyong and Ilardie’s Hill, to the south thereof, are 
ash beds, composed principally of large and small fragments of slate and schist. In 
some places, as on the Werribee Plains, near Mount Mary, the ash beds present a 
stratified appearance, as though their materials had fallen into and had been arranged 
by water. It is probable that this may have been the case, but there is no evidence of 
any very considerable submergence since, as, had such taken place, very few, if any, of 
the volcanic hills, composed as they are of loose incoherent materials, would have 
preserved their form as we now see them. It is probable, however, as suggested by Mr. 
Selwyn, that some of them formed low islands in the Tertiary seas.” 
Of the New South Wales Volcanic Eocks, the late Mr, C, S. Wilkinson wrote *: — 
“ The volcanic rocks, dolerite, basalt, amygdaloid, Ac., are almost entirely of Tertiary age. 
They occur in many places on the high lands of the Great Dividing Eange, forming 
■jlateauB, and also upon its eastern and western slopes. They have been chiefly erupted 
from ‘ pipes or fissures,’ without forming any of those conical hills with crater-basins 
which so characterise many of the points of eruption in the volcanic districts of Victoria. 
The lofty Conobolas, near Orange, arc, however, extinct volcanoes. 
“In the Gulgong Gold Field we have amygdaloidal basalt containing analcime, 
stilbite, &c. From its position in regard to the drifts, it is probably of Upper Miocene 
age; while overlying the Pliocene drifts (deep leads) in the same locality occur extensive 
flows of basalt, which have filled up old valleys, and here and there spread out over 
considerable areas. Similar occurrences may be observed in the stanniferous districts 
of Inverell and in several other parts of the colony. 
“ Basaltic rocks occupy some of the highest points of the Dividing Eange near 
Kiandra, as at Mount Table-top, which is over 5,000 feet above the sea, and which the 
late Mr. Lament Young, who explored it in 1880, regarded as a point of eruption. 
* Notes on the Geology of New South Wales, by C. S. Wilkinson, Government Geologist. Sydney : 
by Authority : 1882, p. 62, 
