292 C. A. Cotton — Block Mountains in New Zealand. 



toto depression are at present confined to shallow valleys, the 

 fiood-plain floors of which, though of no great width, open oot 

 downstream and become continuous. They form a plain which 

 slopes towards the confluences of the streams with the Taieri 

 and is accordant with the valley plain of the Upper Taieri. 

 The recent revival of erosion along the base of the northern 

 fault scarp is perhaps due to climatic changes affecting the sup- 

 ply of waste to the headwaters of the streams. The valley 

 plains and the terraces are covered by a layer of greywacke 

 gravel. 



In the southern part of the Manuherikia depression the 

 relief is considerable. There are broad areas of high terrace 

 owing to the recent deepening of the valley of the Clutha, of 

 which the Manuherikia is a tributary. The effect of this may 

 extend into the upper Manuherikia; but it has not yet appeared 

 to affect the streams of the Ida Yalley depression ; while those 

 of the Maniototo depression do not belong to the Clutha 

 system. 



There has been a small rejuvenation in the Taieri River 

 where it flows through the Strath Taieri depression ; but the 

 floor of this narrow fault angle is for the most part a valley 

 plain. 



LIST OF PAPERS TO WHICH REFERENCE IS MADE. 



Andrews, E. C: Some interesting facts concerning the glaciation of south- 

 western New Zealand, Australasian Assoc. Adv. Sci. Rept., 10th 

 (Dunedin) Meeting, pp. 189-205, 1905. 



Beal, L. 0.: On the deposition of the alluvial deposits of the Otago gold- 

 fields. New Zealand Inst. Trans., vol. iii, pp. 270-278, 1871. 



Bell, J. M. : The geology of the Parapara Subdivision, New Zealand Geol. 

 Survey, Bull. S", 1907. 



Cotton, C. A.: The physiography of the Middle Clarence Valley, New 

 Zealand, Geogr. Jour., vol. xlii, pp. 225-246, 1913. 



On the relations of the great Marlborough conglomerate to the under- 



lying formations in the Middle Clarence Valley, New Zealand, Jour. 

 Geology, vol. xxii, pp. 346-363, 1914. 



The structure and later geological history of New Zealand, Geol. 



Mag., vol. iii, pp. 243-249 and 314-320. 1916 a. 



Block Mountains and a "fossil" denudation plain in Northern Nel- 



son: New Zealand Inst. Trans., vol. xlviii, pp. 59-75, 1916 6. 

 Davis, W. M. : The convex profile of bad-land divides. Science, vol. xx, 

 p, 245, 1892. 



The Mountain ranges of the Great Basin: Harvard Coll. Mus. Comp. 



Zool. Bull., vol. xlii, pp. 142-177, 1903. 

 The Wasatch, Canyon, and House ranges, Utah, Harvard Coll. Mus. 



Comp. Zool. Bull., vol. xlix, pp. 15-57, 1905 a. 

 The geographical cycle in an arid climate, Jour. Geol., vol. xiii, pp. 



381-407, 1905 &. 

 Observations in South Africa, Geol, Soc. America Bull., vol. xvii, 



pp. 377-460, 1906. 



Die erklarende Beschreibung der Landformen, Leipzig, Teubner, 1912. 



Nomenclature of surface forms on faulted structures, Geol. Soc. 



America Bull., vol. xxiv, pp. 187-216, 1913. 

 Finlayson, A. M.: Some observations on the schists of Central Otago, New 



Zealand Inst. Trans., vol. xl, pp. 72-79, 1908. 

 Gilbert, G. K. : Progress report for 1872, U. S. Geog. Surveys W. 100th 



Mer., p. 50, 1874. 



