Vol. XXVII, 

 1910 



] Excursion — Toorak, Richmond Park, Hawthorn. 8; 



features in this splendid geological section of Silurian sandstones 

 and shales. The crushing that has gone on here must have been 

 enormous, for the strata are crumpled in all directions, and the 

 whole section is made up of faults, dykes, anticlines, synclines, 

 &c. Perhaps the most striking is a very fine monocline. The 

 pressure must have been intense, for the layers are in places 

 bent at right angles. The colouration of the clayey layers in it 

 is splendid, from the most delicate pink through to the reds, 

 browns, and yellows, a fine illustration of the effect of iron, 

 Nature's great colouring agent. Owing to the difficulty of 

 getting the right position, my photographs do not by any means 

 convey a good idea of this remarkable monocline. As we 

 approached Heyington station a fine Blue Crane was disturbed, 

 and flew across the river. 



Leaving the cutting and passing Heyington station, we were 

 able to study a fine meander of the River Yarra. Here we 

 noticed that the left bank was steep and high, while the other 

 was low, with a gentle slope. This is the result of the volcanic 

 flows before-mentioned, which filled up the old valley of the 

 Yarra, and forced the river to seek a new valley for itself. This 

 it did by working its way into the softer sedimentary rocks at 

 their junction with the hard basalt. We were able to make 

 a good comparison between the two formations, for, while the 

 sandstone surface was carved into ridges and valleys by the 

 eroding action of running water, and bearing rather a scanty 

 growth of pasture, the lava plain was almost level, with a fine 

 thick growth of excellent grass. Our path then led to the rafl- 

 way bridge over the river, from which, looking down stream, 

 we saw some very good examples of how lakes may be formed 

 behind raised flood plains by tributaries running at right angles 

 to the main stream. 



Crossing the bridge into Richmond Park, we wended our way 

 round the Burnley Horticultural Gardens, and noted some 

 " billabongs " along the Yarra. We then recrossed the river 

 by the Swan-street bridge, our objective being the now disused 

 basalt quarry in Morang-road, Hawthorn. This is a feature 

 of much interest, as it is one of the few places where the basalt 

 is found on the left side of the Yarra. The occurrence is ex- 

 plained as follows : — The bed of Hawthorn Creek (a small 

 tributary of the old Yarra) was not elevated enough to prevent 

 the lava flow from entering its valley, so it was filled up. This 

 formed, as it were, an arm, or off-shoot, from the main body 

 of the molten material. It followed up the valley of this creek 

 for a considerable distance, and is shown on the Geological 

 Survey,: map to extend as far north as Denham-street, and, 

 when the sewerage contracts were in progress, was traced 

 eastwards nearly to Elgin-street. Evidences in the quarry 



