Hardcastle. — The Tlrnarn Loess an a Climate Eegialcr. 331 



range of the loess ou Banks Peninsula may be a peculiar evi- 

 dence of the contemporary climate. I read tliat it extends 

 only some 800ft. up the hill-sides. Why so ? It cannot be 

 that was the limit — j^his the amount of any subsidence since — 

 to which winds could lift the loess-forming dust. Does not 

 this limit of height mark what was practically the limit of 

 vegetation capable of entrapping and retaining dust — in other 

 words, the snow-line? 



If we suppose the ice retreated from the field of its 

 greatest extension to the limits marked by the great lake- 

 dams, we have to deal with a great amelioration of climate, 

 and the change appears to have been as sudden as it was 

 great. There is an absence of marks of gradual retreat over 

 the country generally, and the great moraines have almost as 

 definite a limit of commencement as of termination. The 

 second great thaw, under the influence of which the glaciers 

 retreated to something like their present dimensions (or it may 

 have been further back), also apf)ears to have been a sudden 

 thaw. It was certainly very rapid, compared with the length 

 of time occupied in building up the great terminal moraines. 

 The fans, which originate from those moraines, also appear 

 to have been completed by an extraordinary, one might say a 

 cataclysmic, i-ush of water, not by ordinary river-action. The 

 small terraces and gutters which make old river-beds rough 

 travelling are absent from the surfaces of the fans, where these 

 have not been smoothed over by a surface of soil. A sweeping 

 rush of water would account for this. Probably, in some 

 cases such a rush of water might be attributable to breaches 

 in lake-darns, but scarcely in all cases. One of the most 

 remarkable instances of the smoothing of the surface of a fan 

 is that of the small fan of the Waihi (Woodbury), of which the 

 matCiial is, at the gorge, very coarse and bouldery. The river 

 at its highest now is but a small stream, that could scarcely 

 cover the levelled upper portion of the fan. It seems to me 

 that this fan could onlj' have been levelled in the manner it 

 was (before subsequent terracing on one side) by a powerful 

 rush of water. And there is no lake on any of its branches, 

 but it drains a bulky mountciin, which at the time glaciers 

 filled the great lakes probably carried a heavy load of snow. 



Much has been written about the great glacier period, but 

 I do not remember having seen attention drawn to the sudden 

 termination of the work of building the moraine dams. The 

 compactness of those great terminal moraines, their small 

 breadth in proportion to the length of the glaciers which piled 

 them, suggests a corresponding steadiness of climate. This, 

 however, may be misleading ; the moraines may be the record 

 not of a continuous and equable period of cold, but of a series 

 of maxima of nearly equal intensity. If such was the case,. 



