older Bdtudts oj iirecm^hoiniKjIt, etc. 49 



general level. The latter also appears to be continuous with that of 

 similar deposits to the south referred to above In their lithologi- 

 cal and general eharatters, the deposits are similar, except that in 

 the Greensborough aiea they are much coarser-grained in places, 

 consisting largely nf very heavy gravels.^ This, however, is what 

 would be expected on ajDproaching the hills (to the north), from 

 which the rocks are derived. The most reasonable inference is that 

 the Greensborough sediments belong to and are of the same age as 

 those to the south. These, by the fossils obtained at Royal Park 

 and Beaumaris, have been placed as Kalinman, so that if the 

 Greensborough gravels and sands belong to this period, the Older 

 Basalt of the district may be considered as Kalimnan, or younger. 



The Older Basalt at Royal Park and other localities farther west 

 underlies the Barwonian, hence it must be of this or of an earlier 

 age. There is therefore a very considerable time gap between the 

 Older Basalt of Royal Park, Saltwater lliver, etc., and the Older 

 Basalt of Greensborough. 



The latter rock is much older than the Newer Basalt of the plains. 

 The Greensborough area clearly shows (as pointed out by Mr. Hart) 

 that before the eruption of the Newer Basalt, the Older Basalt had 

 been nmch denuded and the country deeply dissected. A large time 

 gap also therefore exists between the Older Basalt and the Newer 

 Basalt of the Greensborough district. There is thus evidence of 

 three distinct basalt periods, separated by wide intervals of time, 

 m the neighbourhood of Melbourne. 



If the Older Basalt of Greensborough were of the same age as 

 that of Royal Park, the underlying sediments would be much older 

 than Kalimnan. and would probably be contemporaneous with the 

 sedimentary beds below the Royal Park basalt, but the available 

 evidence points in the writer's opinion rather to Kalimnan age 

 than to a much older period. 



In the Greensborough ai-ea, most of the Kainozoic sediments are 

 closely associated with the basalts. The latter have apparently 

 acted as protective caps, and when the basalt is removed the sedi- 

 ments soon follow. Farther south there are numerous outcrops of 

 sediments uncapped by basalt. Greater thickness of sediments in 

 this direction (towards the sea) would, however, be expected, and 

 this thickness would temporarily save some rocks from removal by 

 denudation. In view, moreover, of the evidence brought forward 

 in this paper, it is impossible to say to what extent basalt may have 

 overlain the sedimentary rocks. 



1 Similar gravels are .also found at Kangaroo Ground. 



