Geological Structure about Mornington. 45 



The character of the beds has been descriVjed sutiicieiitly fully 

 by Mr. Kitson, and though, for convenience, we call the beds 

 fei'ruginous, yet the superficial portions, as is usual in such 

 strata, are bleached more or less completely, and much of the 

 district is covered by a sandy loam. 



Posf-J^ocefie. 



Since the surface does not seem to have been submerged since 

 Eocene or, possibly, Miocene times, the classification of the 

 subaerially-formed beds is an academic rather than a practical 

 one. The valleys are mostly short and steep on the western 

 slopes, so that any recent alluvium is of small extent. Towards 

 the west and north the low-lying ground is often swampy, and 

 here the beds are of recent age. Mr. Kitson has arrived at the 

 same conclusion, and is content to map a large area as " Eocene ? 

 to Holocene," and his map is of great use to anyone wishing to 

 further explore the locality. 



It is clear that the western boundary, facing Port Phillip, 

 owes its abrupt rise in the main to the fault which let down the 

 Jurassic freshwater beds. Whether the eastern side of the long, 

 narrow ridge, of which Mount Eliza forms the granitic nucleus, 

 is due to the same cause is not so evident, though quite possible. 

 The descent of the surface is more gradual, except about 

 Moorooduc, and here a small creek, flowing south to enter the 

 sea at Mount Martha, working along the strike of the eastward- 

 dipping palseozoic beds is evidently the cause of the scarp. 



The absence of clear sections in many of the critical localities, 

 and the difficulty of interpreting many of the exposures, is due, 

 we believe, to extensive landslips of the soft tertiary beds down 

 the steep western slope towards the Bay. Had the questions 

 involved in a discussion of the geology of this ai'ea been easy of 

 solution, an adequate account would long ago have been written. 

 As it is, our interpretation of some of the points at issue may not 

 be the correct one, but it is better to have some definite basis for 

 future work. 



We have to thank Messrs. J. A. Kershaw, F. E. Grant, and 

 E. O. Thiele for the gift or loan of fossils which have added 

 several important forms to our list. 



