Art. IV. — Notes on Some Recent Marine Deposits in the- 

 Neighbourhood of Williamstown. 



By F. E. grant and E. O. THIELE. 



[Read 12tli June, 1902.] 



On the northern shores of Port Phillip, immediately to the' 

 west of Williamstown, there is a considerable series of beds of 

 recent age^ lying principally in depressions in the basalt, which, 

 is the prevailing rock of the district, but which, as a reference 

 to the Geological Quarter-Sheet shows, extends in places for 

 more than a mile inland. 



The best section at present exposed for the examination of 

 these beds occurs at a point on the now disused Railway to 

 Altona Bay, about 200 yards west of the Kororoit Creek, about 

 2^^ miles from North Williamstown Railway Station, and about 

 a quarter of a mile from the sea — lying immediately at the 

 back of the Williamstown Racecourse. This particular spot has 

 been referred to by Messrs. Hall and Pritchard^ as a Post 

 Tertiary marine deposit considerably above sea level. At this- 

 point the beds appear to be about 8 feet thick, and do not lie in 

 a hollow in the basalt, but form part of a small rise through, 

 which a cutting about 5 feet high has been made for the purposes 

 of the railway. At the north-east end of the cutting the rock; 

 is entirely basalt, the surface of which is seen to slope sea- 

 wards, passing at first under a thin layer of shells and travertine 

 and then disappearing altogether beneath the shell beds, which 

 show for the entire depth of the cutting at its south-western end. 

 These beds consist very largely of shells, intei'stratitied with a 

 a little fine white sand, and are regularly bedded. By careful 

 collection over SO species of Molluscs, also Echinoids, Polyzoa, 

 Corals, etc., can be readily obtained from the face of the cutting, 

 but we have so far been unable to find any which cannot be 



1 Proc. Roy. Soc. Vic, vol. ix. n. s., art. xiv. 



