6 Excursion to Kovkupervimul Creek (Bacchus Marsh). [vj."^'xxxv. 



The formation of this scarp diverted the Werribee and Lcrder- 

 derg Rivers, and in the process of cutting through this im- 

 pediment to its course the Werribee River formed the famous 

 gorge, the entrance to which was just visible to the south-west. 

 The union of the two rivers gradually formed an alluvial flat, 

 now very many acres in extent, and known throughout Victoria 

 for its wonderful fertility, the soil in many places being upwards 

 of twenty feet in depth. The party then proceeded towards 

 the Korkuperrimul Creek, which, flowing from the north to 

 the Werribee River, crosses the Ballan road just bej^ond the 

 junction of the road to Bald Hill. Here, on the side of the road 

 before reaching the bridge, an ironstone outcrop occurs, in which 

 may be found leaf impressions of two trees which at one time 

 grew in the neighbourhood. On splitting some of the pieces 

 of stone, fairly good specimens of Cinnamomitm polymorphoides, 

 M'Coy, and Laurus werribeensis, M'Coy, were obtained. We 

 then proceeded northwards, and on the slope of Bald Hill 

 inspected the upper beds of Permo-Carboniferous origin which 

 are there exposed in a ravine. Although fossils were obtained 

 here on the previous excursion, time prevented the party seeking 

 for them on this occasion. Further north, in a somewhat 

 damp depression, a number of fine mushrooms were gathered, 

 some of which measured six and eight inches across. A little 

 further north an intrusive dyke was pointed out, from which 

 some large orthoclase felspar crystals were obtained. It was 

 now time for lunch, so, obtaining water from a neighbouring 

 farm-house, we selected a shady spot near a big red gum, and 

 boiled the billy. The pools marking the course of the creek 

 teemed with animal life and algge, but unfortunately the 

 microscopists of the party had not brought their collecting 

 apparatus. Feasting and resting over, we resumed our walk 

 up the stream, such as it was, and at a bend inspected a cave- 

 like hole hollowed out of the glacial till. One of the party 

 took a fancy to a rounded pebble partly exposed in the face, 

 and succeeded in extracting it without much damage. It 

 proved to be a water-worn granite stone deposited in its recent 

 position many thousands of years ago ; now it is to rest in the 

 National Museum collection as a somewhat unique specimen, 

 the included stones in the glacial till being generally angular. 

 The fault line between the Permo-Carboniferous beds and the 

 Older Basalt was seen at several points along the creek. The 

 hills composed of Older Basalt were also more closely inspected, 

 when the different terraces marking succeeding layers or flows 

 of lava were seen to stand out prominently at places, making 

 an imposing sight, and seemed to indicate that the Older 

 Basalt had here a thickness of nearly i,ooo feet. Further along 

 the course of the creek some monchiquite dykes were pointed 



