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



faces in Otago have been termed bj Park (1906, 1910) the 

 Barewood Plateau or Central Otago Peneplain ; and Speight 

 has recognized a similar surface in the Kaimanawa Mountains 

 in the North Island (1908). 



The most perfect examples known to the writer are those 

 forming the back slopes of some of the block mountains of 

 Central Otago, for example, the western slope of Pough Pidge 

 (see tig. 3); a long northeasterly slope from the broken pla- 

 teaus of Central Otago to the fault-angle depression followed 

 by the Shag Piver ; a similar slope southeastward to the Taieri 

 Plain ; a similar slope northeastward from the Kakanui Moun- 

 tains towards the Oamaru district (see iig. 4) ; the westward 



Fig. 4. 



Fig. 4. Part of stripped plateau surface descending northeastward to 

 Oamaru district, Otago, with, a deeply incised gorge, that of the Waianakarua 

 Eiver, on the right, and a large residual mesa of the overmass just to the 

 right of center. 



slope of the Hunter's Hills, noted by Thomson, with which 

 are associated similar slopes surrounding the Waihao basin ; 

 the surface of the Grouland Downs, Northwest Nelson ; and 

 the northwestward slope towards the fault-angle depression 

 followed by the Aorere River, northern Nelson. 



Salievts on Sir ipped Plateaus. — The generally flat surface 

 of a stripped plateau will be broken by a pattern of reentrant 

 ravines. Salient features may or may not be present. Such 

 may have originated as monadnocks on the eroded surface of 

 the undermass which has been lately reexposed, or as small 

 isolated fault blocks in which the surface of the oldermass has 

 been uplifted above its level in surrounding blocks ; or they 

 may be remnants of cover not yet removed, thus closely resem- 

 bling monadnocks in form. Certain remnants of cover may 

 owe their preservation to local induration or local thickening 

 of a relatively resistant stratum and to the presence of a lava 

 flow of small extent. Mesas or buttes of covering strata may 

 thus be scattered sporadically over a surface. Other salients 

 may owe their preservation to slight inequalities of uplift which 

 have caused unusually wide interfluvial spaces between conse- 

 quent streams. Salient features developed from monadnocks 

 and from small uplifted blocks niay be distinguished with 

 great difliculty even when flrst laid bare, for monadnocks may 



