HenukR80K. — Surface Furiiis (ind Drai ii(i{ft'-si/sti'iiis of Wrsf Xelmii. 309" 



the granite ranges south from Mount Domett, enters the Mokihiuxii basin 

 by Eough-and-Tumble Creek, thence along the Upper Ngakawhau and 

 Waimangaroa, past Mount William, and across the Buller by way of Cascade 

 Creek ; thence it flanks the Paparoa peneplain to Point Elizabeth : a 

 branch probably crosses the Grey between the first and second gorges. 



The faults of west Nelson, as far as the writer can tell, are all distributed 

 faults, often many chains wide. • 



Peneplains. 



The fractures of which the general course has just been indicated 

 separate the two main elements in the geography of the area, the pene- 

 plains and areas of depression. 



The most northerly elevated earth- block is that forming the Whaka- 

 marama Range. This peneplain has a north-east and south-west exten- 

 sion, and is bounded by the Aorere and Wanganui faults. The highest 

 peak is 3,980 ft., and several peaks attain 3,500 ft. This block consists 

 mainly of Palaeozoic rocks with a north and south or north-north-east and 

 south-south-west strike.* It is skirted on the west by a belt of - Tertiaries, 

 and is overlain on its northern limb by the same rocks. t 



The Pikikirima penej>lain is bounded by the Motueka and Takaka 

 faults. The highest peak is 4,359 ft., and the average of five peaks is 

 3,920 ft. The slope is to the north half of this earth-block, to the north and 

 east is of granite, the rest of Palaeozoic rocks, f the strike of which varies 

 much from north-east and south-west to north and south. J 



The Moimt Arthiu' peneplain is the principal one in this part of the 

 country. From it have been carved the Momit Arthur, Douglas, Haupiri, 

 Auatoki, and Leslie Ranges. It is hmited by the Takaka and Motueka 

 faults on the east ; on the west by the Aorere fault and by a probable 

 continuation of the Mount William fault. It is separated from the Lyell 

 peneplain on the south by the saddle between the Baton and Karamea. 

 This depression may be a fault-rift, or it may be a col between the trun- 

 cated domes (uplifted by the laccohtes beneath) of the Mount Arthur and 

 Lyell peneplains. The Mount Arthur peneplain is traversed by the Kara- 

 mea fault, which cuts off the Mount Arthur Range from the rest of the 

 peneplain. The highest point is 6,000 ft. above sea-level, and the mean of 

 eleven peaks is 5,110 ft. Granites appear right along the eastern and 

 western borders of this earth-block, and in patches in the north ; in fact, 

 the Palaeozoic sediments which form the central portions rest on a vast 

 plinth of granite. § These sediments contain numerous dykes, and strike 

 fi'om north-west and south-east to north-north-east and south-south-west. I 



The Lyell peneplain is determined on the east by the Motueka fault, 

 on the west by the Mount William fault, on the north by the col before 

 mentioned, and on the south by the Upper Buller Gorge, which the Buller 

 has formed by cutting through the saddle between the Lyell and Victoria 

 peneplains. The Karamea and Matiri faults traverse this peneplain. The 



* Cox : Geol. Surv., No. 15, p. 66. 



t Park : Geol. Surv., No. 20, p. 186 et seq. 



iCk)x: Geol. Surv., No. 13, p. 2. Park: No. 20, p. 228. Hochstetter'.s '• New 

 Zealand," p. 102. 



§Mackay: Geol. Surv., No. 12, pp. 102, 122. Cox: No. U, pp. 43. 44; No. 15, 

 pp. 63, 64. Park : No. 20, pp. 230, 231. Bell : N.Z. Geol. Surv. Bull. No. 3 (n.s.). 

 p. 70 et seq. 



H Maekay : Geol. Surv., No. 12, pp. 125, 127, 128. Cox : No. 14, pp. 45, 49, 50, 51 . 

 Park: No. 20, pp. 210, 211, 213, &c. Bell: N.Z. Geol. Surv. Bull. No. 3(n.s.),pp. 34, 45. 



