400 Transactions. — Geology. 



expect to find, in an extended coast line like that of tliis province, that each 

 effort of the force should be simultaneous, or of a like nature over extended 

 areas. It is more natural to suppose that the action would be partial, here 

 an elevation, there a depression — ^and this is found to be so, though on the 

 whole these notes will prove, that the tendency has been in its latest mani- 

 festation an upward one, and that of a very general nature. 



The first extract to Avhich attention is called is to found in the proceed- 

 ings of the Wellington Philosophical Society, under date July 28, 1868, 

 when the chairman read a short paper " On indications of changes in level 

 of the coast line of the southern portion of the North Island as deduced 

 from the occurrence of drift pumice." Mr. Crawford remarked, " That 

 pumice, having a small specific gravity, floats on the water, and in rivers 

 flowing from the volcanic plateau in the interior of the island it may be 

 seen descending in great quantities and at all hours towards the sea. When 

 there, it is of course liable to be washed up at any part of the shore, and 

 if there is no cause again to carry it away, it necessarily remains stranded. 

 Pumice is found on the flats of the peninsula, near this city (Wellington) at 

 a height of about eight or ten feet above the present high-water mark. He 

 had not observed it on any of the coast terraces, consequently it is probable 

 that the land had attained within 10 or 20 feet of its present level before 

 the volcanic chain sent pumice to the sea ; and this will give an age to the 

 present coast line, or to one from 10 to 20 feet lower (supposing a steady 

 rise of the land), enough to satisfy a very ardent lover of antiquity." He 

 concluded by saying, " It may therefore be held that the probabilities are 

 against any great oscillation of the present sea-level in this part of the 

 North Island since the commencement of the vast period which must have 

 elapsed since the central volcanic group of Tongariro and Kuapehu (and 

 Mount Egmont inclusive) began to send down pumice to the sea." 



Dr. Hector said, " That pumice was a mechanical variety of obsidian, 

 the most perfectly fused product of volcanic eruptions, and did not indicate 

 any particular era in volcanic eruption or elevation of a chain of mountains 

 as Mr. Crawford seemed to require for his theory. * * * Mr. Crawford 

 did not prove by his paper that the sea had not been relatively lower ; or, 

 in other words, that the land had not been undergoing submergence. The 

 sea could never have been at a much higher level, or the pumice would 

 have been drifted up, but there is every reason to believe that the country 

 was much higher formerly, and in the interior contained larger lakes, by 

 which the pumice would be drifted up at great heights above the sea." 



In an essay on the geology of the North Island by the Hon. J. C. 

 Crawford, printed in the appendix to the first volume of" Transactions," that 

 gentleman, referring to terraces and raised beaches, says, — " These form a 



