270 P rucecdiiKjti of Ihe lioi/ai Soclely of Yiclorhi. 



it was known that icebergs when they grounded did not 

 produce strict, in fact could not do so. When an iceberg 

 grounded it swung round on its heel, and if it produced an_y 

 marks at all on the rock, in the first place it bruised the 

 rocks, and in the second ]:)hice the rocks which had been 

 embodied in the iceberg and touched the rocky bottom 

 in the bed of the sea, produced marks wliich were arcs of 

 circles. Icebergs never made straight lines. Then there 

 was another line of argument, which to his mind entirely 

 disposed of the iceberg theory. The Mesozoic sandstone 

 was essentially of fresh or brackish water formation. 

 The only fossils found in the Mesozoic, were two fresh 

 water mollusca and the vegetable remains of ferns. A])art 

 from this, the form.ation liad all the characteristics of sedi- 

 mentary beds which had been formed in a lake. It was 

 known to most geologists, that the Mesozoic sandstone was a 

 fresh water lake deposit. Our mountains at the time it was 

 formed were very much higher than they are now, and a 

 series of lakes were formed between their shelving sides, and 

 as the lakes got tilled up with the sand which now formed the 

 Mesozoic sandstone, the water rose higher.' There was very 

 little doubt that it was never anything else than a shallow 

 fresh water lake, perhaps of considerable dimensions. He 

 would like to knovv how icebergs were going to float in fresh 

 shallow water. An icebeig had one part above water and 

 eight parts below. How were icebergs to float ? This was 

 not a marine deposit, and although 2500 feet in thickness, 

 we might depend upon it this Mesozoic sandstone had 

 accumulated gradually, and as it accumulated at the bottom 

 of the lake, the water had risen. No iceberg ever could 

 have floated in these waters, and therefore, in his opinion, 

 no icebergs could ever have caused these marks. There 

 was also another important piece of evidence that should 

 not be disregarded. Around all the remains of all these 

 ancient lakes in Victoria, below the sandstone bed was 

 found a bed of conglomerate. This was apparently the 

 case at Bacchus Marsh, with regard to the conglomerate 

 under discussion. The officers of the Government Geological 

 Survey attributed the bottom member to the action of 

 the water on the coast. Wherever the margin of this 

 sandstone was found, the conglomerate was found under 

 it. On the whole, the evidence was rather favourable 

 to a glacial origin for the bottom deposits at Bacchus 

 Marsh, and he attributed them to land ice,* not to icebergs. 



