[rBOC. Rot. Soc. Victoria, 34 (N.S Pt. I., 1921]. 



Ar'I'. 11. — The Age of the Ironstone Beds of the Mornington 

 Peninsula, as adduced from the Marine Fa/una* 



By FREDERICK CHAPMAN, A.L.S., F.R.M.S. 



(Palaeontologist to the National Museum, and Lecturer on Palaeontology, 

 Melbourne University.) 



[Read 14th April, 1921.] 



The Related Tertiary Beds. 



This peninsula is bounded on the west by Port PhilHp Bay 

 and on the east by Western Port. Owing to the dissection of 

 this area by faulting, and also through the complication of its 

 earlier structural featiu'es by local flows of basalt of the Older 

 Period, which partially obscures an undeveloped river system 

 of Miocene times, the geological succession of the various Ter- 

 tiary beds are here difficult to make out in true detail. 



As regards the position of the Grice's Creek and Balcombe 

 Bay fossiliferous marine marls, these fall into line with beds 

 in other areas, as at Muddy Creek (lower series) and the lower 

 beds in the Altona Bay coal-shaft and the Sorrento Bore, all 

 of which are of Oligocene (Balcombian) age, and therefore 

 are at the base of the Tertiary system as developed in south- 

 eastern Australia. 



But between these Balcombian and the Kalimnan beds of the 

 peninsula there should occur a series representative of the great 

 diastrophic movements on sea and land during the Miocene 

 period. The question arises : Have these beds been recognised ? 

 In reply to this it may be remarked that geologists have for 

 many years been feeling their way to some kind of conclusion 

 which has a more or less direct reference to the subject matter 

 of this note, without reaching a definite conclusion — hence this 

 present attempt. 



Earlier References to the Intermediate Series. 



A. E. Kitson (1900), in his ** Report on the Coastline and 

 Adjacent Country between Frankston, Mornington and Dro- 

 niana,"^ shows, in his accompanying map, the widely spread 



* Read at the Ilobart Meeting of the Aust. Assoc. Adv. Sc, held in 

 Melbourne, Jan.. 1921. 



1. Monthly Progress Ref). Geal. &urv. Vict., N.S. No. 1«, 1900, p. 12. 



