160 Proceedings of the Royal Society of Victoria. 



The tuff and lapilli bed has a considerable amount of carbonate- 

 of lime occurring as a coating along the bedding and joint planes. 

 Harder and firmer vesicular basalt, very laminated in places, and 

 considerably decomposed, rests on this bed. It runs to the 

 surface, and varies in thickness from some 20 feet at the 

 southern to 30 feet at the northern end. 



Tlie general appearance of these sections when viewed from, 

 the north up the Werribee gives one the impression that the 

 flows originated at Mount Mary, as they appear to be at a 

 slightly lower level on the eastern than on the western side of 

 the river. 



The nearest point of eruption of any size — other than Mount 

 Mary — to this place is a hill shown in Allot. 23c, parish of 

 Tarneit, on Quarter-sheet 8 S.E., and described thereon as a 

 " Volcanic hill — red scoriaceous basalt." This hill rises to a 

 height of less than 100 feet above the plain, and the summit on 

 the northern, eastern, and southern sides shows a rising succession. 

 of fairly well-defined rims, one inside the other, of scoriaceous and 

 partially laminated dense basalt of light and dark grey colour. 

 On the north-western and western sides the slope is gradual and 

 regular on to the hollow part of the adjoining plain, as if the 

 final flow from the point had run off" in this direction, while 

 simply welling up and solidifying in that position on the 

 northern and eastern sides. On the southern and south-western 

 sides the slope is gradual, but along a low rise. There are 

 present numerous aboriginal stone flakes and occasional imple- 

 ments and pebbles of the same kinds of rocks as on Mount Mary, 

 with the exception of the altered clays. Of these one small 

 piece only, of what has somewhat the appearance of this clay, was- 

 found. The absence of this rock seems to prove either the 

 absence of these clays underlying at a depth, as in the case of 

 Mount Mary, or that the volcanic forces here were not strong 

 enough to break away the walls of the crater and eject such 

 broken blocks, or even to distribute tuffs in the vicinity ; thus 

 being no more than sufiicient to cause the molten rock to quietly 

 well forth and flow away, and this even only on the north- 

 western side. 



Taking the country generally, we find that volcanic products- 

 represented by basalt, scoria, tuff and lapilli cover nearly the 



