REPORTS OF RESEARCH COMMITTEES. 335 



F.— Advances in Physiography in New Zealand in the Last 



Ten Years. 



{By C. A. Cotton, D.Sc). 



G. L. Adkiu* has described the physiography of the coastal 

 district about the mouth of the Ohau River, Wellingtou, an im- 

 portant feature of which is a dissected plain, explained as a 

 coastal plain that has been lowered to some extent by erosion after 

 uplift, and later trenched by streams. The gravel fan of the Ohavi 

 River is also prominent, and various changes in stream-courses on 

 it are traced and are ascribed to successive stages of the Pleistocene 

 period. Adkin has also traced changes of drainage in the foothills 

 of the Tararua Rangef, and has recorded evidence of a small 

 amount of valley glaciation in the higher part of that range, j 



B. C. Astoai§ has described a, strip- of recently-emerged, very 

 rugged sea-bottom at Cape Turakirae, near Wellington. Emer- 

 gence of 95 feet is indicated, and the width of the emerged strip 

 varies from 250 yards to 400 yards. Several beach-ridges of 

 boulders at various levels mark pauses in the movement of uplift 

 that produced the emergence. 



J. A. Bartrumj; has described evidence cf eanergence to thei 

 extent of 600 feet at Westport, on the west coast of the South 

 Island. The highest strand forms a terrace, and is separated by a 

 line of ancient sea-cliffs from a more* recently emerged ccastal plain 

 which extends from the sea-margin to a height of 250 feet. (See 

 also later page for observations njade in ccllabcration with P. G. 

 Morgan.) Bartrum has also described under the name "high- 

 water rock-platforms " nearly horizontal benches very little below 

 high-water mark, which give place to steeper slopes seaward and 

 are ccmmon in the drowned valleys cf the Auckland district. 

 The cutting of these is ascribed to Avave-action working oii sub- 

 aerially weathered material above the level cf water-saturation.^ 

 Bartrum has briefly described the physiographic features of the 

 environs of Auckland**, where, besides mentioning the drcwned 

 valleys and very young volcanic cones of that well-known district, 

 he indicates that prior to its partial submergence the area was a 

 sub-maturely dissected peneplain. 



* G. L. Adkin, The Post-Tertiarv Geological History of the Ohau River and of the adjacent 

 Coastal Plain, Horowhemia Coimtr.'Xorth Island, Trans. N.Z. Inst., vol. 43, pp. 496-520, 1911. 

 Further notes on the Horowhenua Coastal Plain and the Associated Physiographic Features, 

 Trans. N.Z. Inst., vol. 51, pp. 108-18, 1919. 



t G. L. Adkin, Examples of Readjustment of Drainage on the Tararua Western Foothills, 

 Trans. N.Z. Inst, vol. 52, pp. 183-91, 1920. 



t G. I.. Adkin, The Discoverv and Extent of Former Glaciation in the Tararua Ranges, 

 Xorth Island, New Zealand, Trans. N.Z. Inst., vol. 44. pp. 308-16. 1912. 



§ B. C. Aston, The Raised Beaches of Cape Turakirae, Trans. N.Z. Inst., vol. 44, pp. 208-13, 

 1912. 



II J. A. Bartrum, the Geological History of the Westport-C'harleston High-level Terraces, 

 Trans. N.Z. Inst., vol. 46. pp. 255-62, 1914.' 



H J. A. Bartrum, High- Water Rock-platforms : A Phase of Shore-line Erosion, Trans. N.Z. 

 Inst., vol. 48, pp. 132-34, 1916. 



** .1. A. Bartrimi, Phvsiographic Notes on Auckland, Handbook for Scientific Visitors, p. 5, 

 Wellington, 1914. 



