244 THE VICTORIAN NATURALIST. [Vol. XXIII. 



EXCURSION TO CLIFTON HILL QUARRY. 

 After a somewhat threatening sky in the forenoon of Saturday, 

 9th March, the weather proved, later in the day, very favour- 

 able to the 22 members and friends who joined in the above 

 excursion. On reaching the quarry it was at once seen that 

 a great deal of rock had been taken out since our last visit, 

 consequently revealing some new features. The general aspects 

 of the volcanic phenomena shown in this quarry, such as the 

 columnar, spheroidal, vesicular, slaggy, and ropy structures, 

 were pointed out on the way down ; particular notice being taken 

 of the irregular nature of the lava near the sloping track, where 

 it looks as though the scoriaceous rock had been hurtled over 

 a precipitous bank, followed by a flow of the more compact 

 lava. To enable members to judge of the minute structure of 

 the more compact basalt, a lantern slide of a photomicrograph of 

 the basalt, taken from the top of the flow at this quarry, was 

 handed round. A projecting mass of silt stained with car- 

 bonaceous matter, near the floor of the quarry, showed a portion 

 of a tree-trunk embedded in it, and this formed a prominent 

 object lesson. On the southern side of the quarry a fresh 

 exposure had been made, which revealed a pale brick-red tuff 

 bed, similar to that exposed some time since at the eastern end, 

 containing small volcanic ejectamenta(lapilli), first noticed by Mr. 

 T. S. Hall. This new exposure contains, besides lapilli, volcanic 

 bombs measuring more than two inches in their longer diameter. 

 There is, perhaps, hardly enough evidence to decide the point as 

 to the existence of a tuff-cone at this spot although there are 

 unmistakable signs in this new exposure of false bedding, 

 especially where the wind has denuded the tuff, thus differentiating 

 the hard and soft layers. Resting on this tuff bed is a layer of 

 scoriaceous basalt, and this is immediately followed by very 

 ■compact lava. 



The steep ascent to the machine sheds was then made, the 

 party being interested half-way by the sight of a large boulder of 

 basalt showing part of a large vesicle with a layer of pretty 

 crystals of Phacolite on a dark green ground. Our steps were 

 then turned towards the Merri Creek, where we had an op- 

 portunity of seeing a clear section of basalt resting on Silurian 

 mudstone. Some interesting features in the terracing of the 

 Merri Creek valley were pointed out by Mr. J. A. Leach, M.Sc, 

 and a forsaken watercourse of the Merri Creek, leaving a pro- 

 minent islet, was also remarked. Although this excursion has 

 been several times repeated, there are always some fresh features 

 of interest to be seen. 



Among the minerals collected were Aragonite, Ferro-calcite, 

 Steatite, Phacolite, Vivianite, Magnesite, and Halloysitic clay. 

 The rock specimens included compact basalt, scoriaceous basalt, 

 tachylyte, and tuff — F. Chapman. 



