64 THE VICTORIAN NATURALIST. 



in a gully crossing Riversdale-road, the same relationship of red 

 sands to Silurian at about the same level was noted. On reach- 

 ing the top of the hill at Highfield-road (270 feet) it was seen 

 that we were standing on a plateau with a gentle slope to the 

 south-west. The Malvern Town Hall, 2^ miles off in this 

 direction, was visible, and is 200 feet above sea level. It was 

 recalled that the country there was covered by the same red 

 sands. More to the southward the plain about Caulfield, about 

 160 feet above the sea, could be seen across the valley of 

 Gardiner's Creek, which on the line between the two places is 

 about 60 feet above the sea. To the east the plateau is cut off 

 by the broad, deep valley of Dandenong Creek and its tribu- 

 taries, and a glimpse of the Yarra valley was obtained to the 

 north. Far to the ncrth-west and west lay the lava-covered 

 Keilor Plains, which were visible across Melbourne, and which 

 from sea level at Williarastovi'n gradually rise as they sweep north, 

 till at Sunbury they are about 700 feet above the sea at a 

 distance of some 20 miles from the coast. 



The result of our excursion was to have it brought clearly 

 before our minds that to the east of Melbourne a mantle of red 

 clays, sands, and gravels lies over the surface of the Silurian 

 rocks which form the bed-rock of the district. The old surface 

 of these ancient tilted and folded rocks is uneven, but has a 

 general southerly slope. At Surrey Hills, near the reservoir, it 

 rises to 420 feet. At Mentoiie, 12 miles south, its surface is 

 about 560 leet below sea level. On the other hand, al St. Kilda 

 it crops out on the beach, and rises to over 50 feet higher a little 

 to the north. 



About Beaumaris the red sands contain marine fossils which 

 fix their relative age, and these beds, though the matter is in dis- 

 pute, we call Kalimnan (? Miocene). No fossils have been 

 found as far inland as we w^ere, and, judging by the character of 

 the beds, they are not marine, but represent material brought 

 down by streams from the Dividing Range to the north before 

 the Yarra dug its deep trench, which cuts off the plateau in that 

 direction. This material was spread over the land. Speaking 

 broadly, the freshwater beds may be regarded, I think, as of the 

 same age as the marine ones at Beaumaris. 



This sloping, sandy plain has been deeply cut into by streams, 

 even by the intermittent ones, such as Gardiner's Creek and its 

 tributaries, and by what in default of a more poetic name we 

 must call the Hawthorn main drain. 



In our previous excursion, a few weeks ago, to Keilor, we saw 

 that red sands of a similar character, though of somewhat greater 

 age, as the fossils show, underlay the lavas of the Keilor Plains. We 

 can, then, look back to times, before this outpouring of molten 

 rock, when country of a similar character lay all around the 



