Crawford. — On Water-worn Pebbles in the Soil. 341 



Note by Professor F. W. Hutton. 

 This specimen was collected by me in Isthmus Sound, Preservation 

 Inlet, during March, 1874, when I was examining the west coast Sounds as 

 geologist to the Provincial Government of Otago. My observations seemed 

 to show that the granite was intrusive and much younger than the gneiss 

 with which it is associated in Preservation and Chalky Inlets, and in 

 my report to the Provincial Government of Otago* I considered that 

 it had pierced rocks belonging to the Maitai (=Kaikoura) System, 

 and consequently that it was much younger than the gneiss which 

 was considered as of Archaean age. Fragments of the slate are found 

 in the granite, and consequently the slate is the younger of the two. 

 The analysis by Professor Liversidge shows that the granite cannot be 

 metamorphosed slate, so consequently it must be intrusive. The age of 

 the slate is however doubtful, as Dr. Hector in his last geological map of 

 New Zealand has coloured it as belonging to his " foliated schists " of 

 uncertain age. The actual rock in question, however, is not a foliated 

 schist, but an argillite, that is an uncleaved slate, and the alteration 

 produced by the granite does not penetrate very far into it. 



Art. XLIV. — On Water-ivorn Pebbles in the Soil. 

 By James Coutts Crawford. 

 [Read before the Wellington Philosophical Society, 9th July, 1884.] 

 In the soil and subsoil of the Hataitai Peninsula, and I am inclined to 

 believe of all the district surrounding Port Nicholson, water-worn pebbles 

 may be found, in general sparsely distributed, possibly a foot or a yard or 

 more from each other, reminding one of the old story of the school plum- 

 pudding where the drummer-boy had to be called in to beat his instrument 

 to call the plums together. 



The occurrence of these pebbles may seem of small import, but in 

 reality they form a very puzzling geological problem, possibly involving 

 great movements of the earth's surface. How they got into their present 

 position I shall try to explain ; but I am quite open to conviction if any 

 one can produce a more plausible theory. 



An explanation by a subsidence of the land to the extent of 1,000 feet 

 or more is not admissible. There is no appearance of marine strata or 

 action above a height of about 15 feet from present high -water mark. 



It may be suggested that these pebbles are the remains of a conglome- 

 rate, or of a coarse sandstone rock, which has undergone decomposition, 

 but no traces are found of any such rock, 



