394 Prof. J. Park — Pleistocene Olaciation, New Zealand. 



II. — Pleistocene Glaciation of ITkw Zealand. 

 By Prof. James Park, F.G.S., University of Otago, Dunedin, New Zealand. 



(PLATE XIV.) 



IN the June issue of the Geological Magazine^ for 1917 there 

 appears an article by Mr. C. T. Trechmann, D.Sc, F.G.S., on 

 "The Glaciation Controversy in New Zealand", in which he 

 traverses my views as to the extent of the Pleistocene glaciation 

 of this Dominion. I regret that my recent journeys to the Isle of 

 Pines and Cape Yorke Peninsula and the irregularity of the oversea 

 mails arising from the war conditions have prevented an earlier 

 reply. Mr. Trechmann deals first with the glaciation of the 

 North Island. He says it seems to him that the question of 

 the glaciation of the North Island stands or falls with the origin 

 of the striations on the large andesitic boulder lying near Mangaweka 

 in the Rangitikei Valley (see Plate XIV). He selects these striations 

 as the sole criterion of former glaciation, and argues that "if the 

 scratches are not glacial the boulder is not glacial, and if this 

 boulder is not glacial none of the others are glacial, and the chief 

 evidence for a glaciation of the North Island fails ". As a matter 

 of fact this great striated boulder was not discovered by me till 

 1915,^ or some five years after the close of the glaciation controversy 

 between Dr. P. Marshall and myself. ^ Its existence was unknown 

 in 1909. At that time I relied on other evidences of glaciation that 

 Mr. Trechmann passes over with little or no comment. 



I will briefly summarize the other evidences. In 1909* I dis- 

 covered at Turangarere, in the Hautapu Valley, a great tumbled pile 

 of angular and semi-angular boulders of andesite that range in size 

 from I to 6 feet in diameter; still greater piles and larger masses at 

 Mataroa and Tuihape, and a smaller pile at TJtiku. These boulders 

 are foreign to the Hautapu basin, which is composed of Pliocene 

 marine clays that are interbedded with a few thin beds of shelly 

 limestone. The only possible source of these andesitic masses is the 

 great volcano liuapehu (9,000 feet), which is separated from the 

 Hautapu Valley by the Wangaehu Valley and the Waiouru plateau- 

 like ridge that forms the divide between the Wangaehu and the 

 Hautapu lii vers. 



The present distribution of the andesitic piles would tend to show 

 that, when originally deposited, they extended across the Hautapu 

 Valley, and formed barriers that have since been breached by the 

 Hautapu lliver. The smaller material was resorted during the 

 process of excavation, and spread out as gravelly deposits along 

 the present course of the river. 



In 1909 I postulated that the agent which transported the 

 andesitic material across the Wangaehu Valley and the Waiouru 

 divide, and deposited it in widely separated piles in the Hautapu 

 Valley at distances ranging from 20 to 40 miles from its source, was 

 a Pleistocene extension of the existing Ruapehu glacier. 



i Geol. Mag., Vol. IV, pp. 241-5, 1917. 

 2 Trans. N.Z. Inst., N.S., vol. xlviii, pp. 135-7, 1915. 

 ^ Trans. N.Z. Inst., vol. xlii, pp. 589-612, 1909. 

 •* Trans. N.Z. Inst., vol. xl, pp. 575-80, 1909. 



