190 I-'ro<re<liii(/s of the Royal SocU'fi/ of Victoria. 



notable feature of the Korkuperriuiul Creek series, viz., stratitied 

 iBudstones, unstratitied mudstones or conglomerates, and sand- 

 stones. This association occurs again and again on the 

 Korkuperrimul Creek. Ganganiopteris occurs in sandstones at 

 various horizons on the Korkuperrimul, but is most frequent in 

 the uppermost sandstones at Bald Hill. So far we have not 

 detected any fossils in our beds, and from this circumstance, and 

 taking into account the dip and strike of the beds on the S. part 

 of our area on the Lerderderg, we conclude that the Goodman's 

 Creek series lie considerably below the Bald Hill sections, but are 

 probably higher than the lowest on the Korkuperrimul. 



Any theory of the conditions under which the glacial beds 

 were formed has to .satisfy two facts of prime importance, \iz., 

 the well-marked stiatitication of the mudstones and the foreign 

 nature of the included material. Stratification is indeed not 

 entirely absent from glacial deposits elsewhere exposed on the 

 earth's surface, but it nowhere occurs either to the extent or per- 

 fection that it does in the beds of the Bacchus Marsh area. The 

 large development of the stratified mudstones shows that in this 

 <listrict conditions prevailed during the glacial period which have 

 been for the most part aijsent or entirely subsidiary in other 

 glaciated areas. The theory which explains the formation of 

 glacial ))eds elsewhere is inadequate here. As prime agents in the 

 glaciation of tlie district we are limited to either icebergs or a 

 land ice-sheet ; either is a suitable vehicle for the transmission of 

 material from one area to another ; by means of either the 

 presence of the foreign boulders in our beds may be explained, 

 but in attempting to account for the stratification of the mud- 

 stones and the striation of the rock surfaces by means of icebergs 

 grave difhculties present themselves ; to these ditiiculties we have 

 referred in the paper previously mentioned and do not propose to 

 repeat them here. 



In the present paper we a.scribe the glaciation of the district 

 mainly to a sheet of land ice which moved from the south ; of the 

 dimensions of this sheet but little can be said at present ; it may 

 have been and probably was continuous with the one to which we 

 believe the glaciation of the Derrinal area is due, as the beds of 

 this area bear a striking resemblance to those of the Bacchus 

 Marsh area. The front of this ice-sheet terminated eventually 



