president's address — SECTION c. 53 



ol' quartzose mica-paragneiss containing sillimanite, as appears 

 trcm exaniinaticn of mateiial from areas described by McKay 

 (1896). Sillimanite-gneisses also occur in Stewart Island, as well 

 as missive pegmatitic granite. North-west of Preservation Inlet, 

 at Dusky Sound, Park (1888) describes a series^ of arenaceous 

 mica -schists, quartzites and magnesian schists with some lime- 

 stone, lying on the continuation of the strike of the graptolitic 

 rocks mentioned above. Eastwards these Dusky Sound rocks pass 

 into "granitic gneiss," and " felsitic schist" containing mica- 

 schist and crystalline limestone. Apparently the zone of maxi- 

 mum metamorphism here lies to the east of the coastline. The 

 same seems to be the case at Milford Sound. On the other hand, 

 the eastern boundary of the compleix of Fiordland seems to be 

 probably an immense fault (Hutton 1875, 1900; McKay 1892). 

 The easternmost portions of the complex are not noticeably gneissic 

 or schistose, but this structure appears and increases towards the 

 west, reaches a maximum and diminishes as described above. 

 Among the plutonic rocks, the characteristic metamorphic pheno- 

 mena are those of the upper and middle zone as defined by Gruben- 

 mann. This was first indicated by Speight (1910), whose account 

 we may supplement by the following remarks based en material 

 collected and described by Marshall (1905, 1908), and further 

 material obtained by Cotton and the writer. The granites of 

 Preservation Inlet, of Pigeon Island in Dusky Sound, and of 

 Stewart Island, show little or no sign of strain. These may belong 

 to a " newer granite " series, or to the latest portions of the single 

 jjeriod O'f orogeny and plutonic intrusions to be described. The 

 diorite of the Hollyford Valley, on the north-east of the crystalline 

 complex, has also no sign of strain, and differs somewhat from 

 the diorites about the head of Lake Te Anau ana the Clinton 

 Valley, which are more or less crushed, increasingly so as we pass 

 westwards until on the watershed. P'alloon Peak consists of a 

 strongly cataclastic rock, in which epidcte has replaced horn- 

 blende. In the same region also, and on the divide west of the 

 Hollyford River, thf mica-ncrite is strained, may be. morei or less 

 hornblendic or uralitised, and contains zoisite. (Cf. Bartrum 

 1920). West of the watershed, however, the features of the middle 

 zone of metamorphism may be seen. Garnets appear, and poikilo- 

 blastic structure is marked in the hornblende and sometimes m 

 the garnets. This is well seen in a rock from the Bowen Falls at 

 tht liead of Milford Sound, which rock also contains large prisms 

 of clinozoisite. Near the entrance to Milford Sound, the features 

 of the upper zone are approached once more in the characters of 

 the amphibolite and quartz-mica-schist of Anita Bay, in which 

 there are intrusive masses of peculiar cataclastic peridotites con- 

 taining magnesite (Marshall 1905, Speight 19lD). The sillimanite- 

 gneisses of Resolution and Stewart Islands, which show evidence 

 of high temperature, may be the contact-metamorphic effects of the 



