president's address — SECTION c." 117 



situated, not within the land area, but some distance east of the 

 present coastline (Cotton 1916, cf. Hogben 1914, 1918). Between 

 these movements, however, there occurred long periods of rest, 

 during which the cycle of erosion reach an advanced stage. Hence 

 along the coastline in different districts there are more or less 

 marked wave-cut terraces or raised beaches, while extending far 

 up the valleys are benches, or rock- cut terraces, indicating that 

 the valleys are not monocyclic, bat have been rejuvenated from 

 time to time. In the Reef ton district, Henderson (1917) has 

 correlated the raised beaches with the river-terraces extending to 

 a height of 500 feet above the sea-level.* In regions where 

 the crust was tilted towards the coast, the heights of the terraces 

 steadily increase as we pass up the valleys, a particularly clear 

 example being the meandering Rangitikei, which becomes deeply 

 entrenched in its old flood plain. An alternative explanation of 

 the entrenchment of the rivers in Canterbury below their alluvial 

 terraces, has been offered by Speight (1908), who suggests that 

 the river valleys became deeply alluviated during a pluvial period 

 following the glacial epoch, and that succeeding this was a period 

 of greatly diniinished rainfall, during which the now underladen 

 streams cut deeply into their former deposits. The further in- 

 vestigation of crust-movements will be greatly advanced by the 

 wise policy that has been adopted of placing bench-marks at various 

 stations along the coast. 



Such, then, is a summary of the present knowledge of the 

 geology of New Zealand, illustrated for the most part by the work 

 of the past decade. It is by no means a complete summary, for 

 considerations of space have caused the omission of much 

 interesting matter, notably all account ol the modern vol- 

 canic activity. Nor was it possible to consider the advances in 

 our knowledge of features of economic interest, or to enter into 

 much detail in regard to the problems of the faunal relations of 

 New Zealand during various periods. These will long remain 

 fruitful fields for discussion. One thing appears clear: — The out- 

 lines of New Zealand geology were drawn with broad generaliza- 

 tions. TcO' often, perhaps, clear statements of conclusions were 

 based upon incomplete evidence. The present is the time for 

 detailed investigations in all branches of our science; and as this 

 advances, we have the more often toi admire the arduous toil and 

 brilliant insight of those pioneers, Hochstetter, Hector, Haast. 

 Hutton, and that great field-geologist, McKay, by whom, from 

 sixty to thirty years ago, the foundations for onr work were -SrO;, 

 ■well and truly laid. nT" V 



* See also Bartnim, 1914. .. >■ ■■^ 'i^ " ^^, 





