Western Victoria. 63- 



exposed portion forms a syncline about two miles long, the 

 crest of which rises some thirty feet or so above the Vjeach 

 at the Whaler's Bluff, whilst the extremities dip out of sight 

 at the lighthouse to the south, and at the Narrawong siding 

 to the north. 



The upper edge of the synclinal fold has a serrated 

 appearance, probably due to the slipping down of masses of 

 the much decomposed miocene basalt, which forms the 

 upper portion of the cliff 



The rock is a snow-white material, moderately hard, but 

 friable, and very porous. Its matrix is a chalky dust, a 

 mass of microscopic foraminifera, which have been identified 

 as being for the most part, globerigina bulloides, and orbulina 

 universa. There is with these an abundant admixture of 

 bryozoa, echini, pectens, terebratellse, and pteropods, all more 

 or less broken, and an occasional fishbone. The coarser 

 ingredients are often arranged in layers one or two inches 

 thick, and of considerable horizontal extent. These layers 

 stand out in a slight relief on the cliff face, and this seems 

 to be due to the presence in them of great numbers of 

 siliceous organisms, which afford, by their partial decom- 

 position, a siliceous cement, less affected by weathering 

 than the calcareous cement which elsewhere binds the mass. 



This chalk-like limestone is overlaid, conformably as it 

 seems, by a bed composed principally of oyster shells (Ostrea 

 Sturtiana). Owing to the talus of loose decomposed lava 

 from overhead, it is not easy to say what may be the exact 

 thickness of this bed, but I think that it probably averages 

 a foot. 



These two formations, the limestone and the oyster bed, 

 weather more slowly than the volcanic rock above them, 

 and consequently, the cliff face, where it is built up of these 

 different materials, presents a section having a marked 

 character. The portion composed of lava, slopes at an angle 

 of about forty degrees, while that of limestone is almost 

 vertical. (See Sketch H.) 



These formations (the limestone and the oyster bed) are 

 exposed at the surface only in one locality, that of the 

 Borough of Portland. The outcrop there extends from the 

 Courthouse, along the Cliff Road, to the bridge at the. 

 mouth of the Wattle Hill Creek, a distance of about a 

 quarter of a mile, and thence it runs inland up the valley, 

 for about a mile. The creek has cut through a great 

 thickness of volcanic rock, and it has eroded to a small 



