196 



CAPT. F. W. HITTTON ON THE 



secondarj' anticline (e) runs from Hunters Hills, in South Canterbury, 

 northerly to the Two Thumb range, dipping to the north. Mt. Cook 

 is placed at the point where the synclines 6 and c and the anticline e 

 meet (fig. 1, x ). The anticline / runs from the gorge of the Ashley 

 in a westerly direction. In Otago the main anticline turns sharply 

 to the south, dipping slightly in that direction, and on its westei'ly 

 slope a synchne (fig. 1, g) runs from the Greenstone E,iver, west of 

 Lake Wakatipu, through the Hokamii Mountains to Catlin's Eiver, 

 following with considerable exactness the direction of the Otago 

 anticline. In the northern part of the South Island the main anti- 

 cline, turning more to the north, runs out at Tasman's Bay, and is 

 flanked on the north-west by a syncline (h) passing through 

 Snowdon and the Anatoki Mountains to Golden Bay ; and on the 

 south-east by another syncline (i) near IS'elson, followed by an 

 anticline (k) which runs from the neighbourhood of Top-house 

 in a north-easterly direction through Picton and Queen Charlotte 

 Sounds. 



All the sedimentary rocks, up to the Hokanui System inclusive, 

 partake in these flexures. The Waipara System is also, to some ex- 

 tent, involved in Otago and Nelson ; while the rocks of the Oamaru 

 and younger systems either retain their original plane of deposition 

 or are occasionally locally disturbed. These last occupy, for the 

 most part, valleys, or wrap round spurs of the older rocks. A 

 large fault (fig. 1, m) occurs in the west part of Otago, running in 

 a nearly north and south direction through Lake Te Anau, and 

 throwing up the Manapouri System to the west*. ISTo clear evi- 

 dence of the age of this " Te Anau fault " has as yet been obtained, 

 as the junction between the Manapouri and Maitai Systems has not 

 been closely studied ; but it appears to have been formed before the 

 deposition of the Maitai System. 



The North Island is very difierent. A narrow ridge, rising in 

 the Kaimanawa Kange, east of Lake Taupo, to 5000 feet or more, 

 runs from Wellington in a north-easterly direction, to near the 

 East Cape, attaining here also, in Hikurangi, a height of 5500 feet. 

 It is bordered on the south-east by hilly country, occasionally 

 attaining nearly to the altitude of the main range, and on the north- 

 west by country which is broken, but generally low, with the ex- 

 ception of three great volcanic cones — Mt. Egmont (8280), Euapehu 

 (9195), and Tongariro (6500) — near the central part of the island. 

 The rocks also differ much from those of the South Island. The 

 crystalline schists of the Takaka System, which are so conspicuous 

 on the south side of Cook's Straits, suddenly disappear and are quite 

 unknown in the north. The main range is formed by rocks belong- 

 ing to the Maitai and Hokanui Systems, smothered on each side by 

 Tertiary beds, through which rise, at intervals, throughout the Auck- 

 land Province, isolated ridges and peaks of the older Maitais and 

 Hokanuis. 



This sudden change at Cook's Straits strongly suggests the 

 presence of a fault with the upthrow to the south, although it is 

 * ' Geology of Otago/ p. 23, Dunedin : 1875. 



