208 



of red, white, and variegated sands and clays, and the middle 

 and lower portions consist of layers of sandstone which are 

 separated from each other by highly-coloured sands or clays, 

 the whole series being horizontally bedded. The principal 

 sandstone, which has become altered from a loose sand by the 

 infiltration of silica, is about 3 feet 6 inches in thickness, 

 and occurs in the series about 20 feet from the base of the 

 cliff. The sandstone is even-grained, sometimes cross-bedded, 

 and weathers under sea action to a rough surface, and is often 

 cavernous. Some portions of the stone are very siliceous, 

 while others are less so, causing much irregularity in weather- 

 ing (pi. xxvii.). The upper surfaces of the stone show 

 peculiar effects of the siliceous infiltration, producing knob- 

 like protuberances, concentric and serpentine patterns, in 

 low relief (apparently caused by successive waves of silici- 

 fication), some of which look like artificial design, and might 

 be compared with examples of Maori carvings. Slabs of 

 silicified rock alternate with other beds that are less indurated, 

 and the former are sometimes joined by connecting pillars 

 of harder material, which in the case of cross-bedding make 

 oblique angles with the horizontal slabs. 



By the undermining action of the waves the softer beds 

 are washed away, while the harder sandstones remain and 

 litter the beach with very large blocks of stone. No examples 

 of petrified wood were seen in situ , but examples were common 

 on the beach, and a good supply was bagged. The Rev. J. 

 R. Andrew (who accompanied us) in my presence picked up 

 a beach stone of the indurated sandstone carrying the im- 

 pression of a dicotyledonous leaf, which is now in the museum 

 of the Adelaide University. 



The following is a more particularized statement of the 

 beds as they occur at Rocky Point : — 



Sandy soil 



Nodular travertine and calcareous marl 



Yellow indurated sandstone 



Indurated reddish sandstone 



Yellow sand 



Red ferruginous sand 



Calcareous clay (honeycombed) 



Yellow ferruginous sandstone with iron- 

 stone layers 



White laminated clay with yellow and 

 red colouration in transverse joints, 

 and layer of pebbles on top 



Yellow sand 



Siliceous consolidated sandstone .. 



Red, yellow, and purple sandy-clay 



Yellow clay 



Fossiliferous Miocene rock (decomposed) 



80 



ft. 



in 



. 3 







1 15 







. 9 







1 



6 



. 5 







. 3 







. 3 







8 



... 1 



6 



... 7 







... 3 



6 



... 10 







... 4 







d) 6 



6 (above 





— sea level) 



