Januaet 11, 1907] 



SCIENCE 



71 



geography, and hence to include a considera- 

 tion of air and oceans as well as of lands; 

 but as notes on meteorology and oceanography 

 were later handed over to other contributors, 

 and as the attention of the writer of this 

 series of notes came to be more exclusively 

 directed to the forms of the lands, it was 

 found that some readers interpreted physi- 

 ography as meaning the study of land forms 

 only. To avoid this misconception, the notes 

 now offered are placed under an unequivocal 

 title, for which some vsrriters have suggested 

 the single-word name, geomorphology or geo- 

 morphy. However named, the topic here 

 treated is to be regarded only as a large divi- 

 sion of physiography, and not as the whole 

 content of that subject. W. M. Davis 



WESTLAND, NEW ZEALAND 



The chief physiographic features of West- 

 land, a province of the southern island of 

 New Zealand, as described by J. M. Bell 

 (' Geology of the Hokitil^a Sheet,' Bull. No. 1, 

 N. S., N. Z. Geol. Survey, Wellington, 1906), 

 are: An interior alpine chain, trending north- 

 east, flanked on the west by an uplifted and 

 dissected peneplain, and this followed by a 

 coastal plain, which is interrupted near its 

 inner border by outliers of the dissected pene- 

 plain and trimmed along the coast by the 

 sea. The structure of the mountains is syn- 

 clinal in the main ; the highest peaks, 6,000 or 

 7,000 feet, are of grauwacke or sandstone. 

 The snowfields on the higher slopes and the 

 glaciers which descend into all the higher 

 valleys are much reduced from their quater- 

 nary extension. With one exception, the 

 streams issuing from the glaciers do not carry 

 rock flour; this, it is thought, marks the in- 

 efficiency of the present comparatively weak 

 glaciers in eroding the rocky beds of their 

 more powerful predecessors. 



The present altitude of the flanking pene- 

 plain (Wainihinihi) suggests that the alpine 

 chain as well as the peneplain owes its alti- 

 tude to modern massive uplift, as has been 

 found to be true in so many other ranges. The 

 range is therefore only the less consumed part 

 of an ancient mountain system, of which the 

 peneplain is the more consumed part. This 



idea is confirmed by the occurrence of occa- 

 sional elevations which surmount the uplands 

 of the dissected peneplain. The dissection of 

 the uplands has progressed so far in the neigh- 

 borhood of the principal rivers that the 

 isolated mountainous fragments receive dis- 

 tinctive names. The sides of the larger val- 

 leys have been smoothed by glacial action, and 

 in many cases the normal preglacial spurs 

 have been truncated. Cirques in the valley 

 heads, hanging lateral valleys along the main 

 valley courses, and roches moiitonnees in the 

 valley floors are frequently seen. The coastal 

 plain, fronting the Tasman sea, is of complex 

 form. In its first cycle a series of marine 

 gravels and clays were elevated and dissected: 

 the dissected plain was then submerged, partly 

 buried under new sediments, and elevated for 

 renewed dissection, with the higher remnants 

 of the earlier plain rising through the surface 

 of the newer one. The present cycle of dis- 

 section has been complicated by glaciation. 

 The greatest width of the plain is about 

 fifteen miles, and the elevation of its inner 

 border is 600 feet. I. B. 



RIVER TERRACES IN VERMONT 



The theory elaborated by Davis some years 

 ago in regard to the origin of river terraces 

 has been tested by E. F. Fisher, who has 

 applied it to the explanation of the terraces 

 found along West River in Vermont, near its 

 junction with the Connecticut. This theory, 

 as stated by Fisher, is that " the river terraces 

 of New England may be accounted for by the 

 behavior of meandering and swinging streams 

 slowly degrading previously aggraded valleys 

 without necessary change in volume, and by 

 the control exerted here and there over the 

 lateral swinging of the streams through the 

 discovery of rock ledges." It is found that 

 this theory alone is adequate to account for 

 the features noted in the region studied. 



Professor Fisher presents the results of her 

 studies in a paper entitled ' Terraces of the 

 West River, Brattleboro, Vermont ' (Proc. 

 Bost. Soc. Nat. Hist., XSXIII., 1906, pp. 9- 

 42). The lateral swinging of rivers by me- 

 anders, cut-offs and short cuts is considered, 

 and the evidence in favor of a fourth process 



