706 SUBANTARCTIC ISLANDS OF NEW ZEALAND. [Physiography, Geology. 



4. Granites, gneisses, contorted schists, and gabbros occur in a conglomerate 

 at Carnley Harbour. This is a fact of the highest importance, as showing the pre- 

 sence of a continental area in the neighbourhood. 



5. It seems fairly certain that the great outpourings of basalt which form the 

 main mass of Auckland Island were subaerial, and not submarine, even in the earlier 

 stages. No marine tuffs were found underlying the basalts, and a coked peat-bed 

 between two flows of lava not only proves undoubtedly that there was land in the 

 region at that time, but also suggests that the climatic conditions were approximately 

 the same then as now. 



With this introduction, indicating the special points which will be referred to 

 more thoroughly later, the geological history of the Auckland Group may be con- 

 sidered in detail — i.e., as far as our limited investigations enable us to express definite 

 opinions. 



AUCKLAND ISLANDS. 



PHYSIOGEAPHY. 



Introductory. 



The Auckland Islands are situated almost due south of New Zealand, between 

 51° and 51° 30' S. lat., and between 165° 50' and 166° 15' E. long. They are thus 

 5 degrees south of the southern part of New Zealand. The depth of the sea between 

 them and New Zealand is nowhere greater than 200 fathoms. An elevation of 

 1,200 ft. would therefore connect the islands with New Zealand. The sea is swept 

 by constant heavy gales, as it lies well within the belt of prevailing westerly winds 

 that encircles the globe between latitudes 40° and 60° S. The winds have exerted 

 a marked effect, directly and indirectly, not only on the vegetation, but also on the 

 coast-line of these small islands. 



The group consists of two principal islands, of which Auckland Island proper is by 

 far the largest, being twenty-five miles long and seventeen broad at its widest part. 

 This island will be referred to in this physiographical account as "the mainland." 

 Adams Island lies immediately to the south of it, and is separated from it by Adams 

 Strait, or Carnley Harbour, as it is more commonly called. Adams Island is some- 

 what long and narrow, lying parallel with the general direction of the shore of the 

 mainland. This island is nearly fifteen miles long, and about five wide in its widest 

 part, but its average width is little over two miles. At the north end of the group, 

 lying round the entrance to Port Ross, there is a small archipelago, of which Enderby 

 is the chief island. The other islands are Ewing Island, Ocean Island, and Rose 

 Island. To the west, separated by about five miles of sea, is Disappointment Island, 

 of comparatively small size, being not more than two miles across. The general 

 shape of the group is like a blunt-ended pear, with the thick part pointing south. 



Coast Features. 

 The sea from which the islands rise is comparatively shallow. Along the north- 

 eastern coast there extends a fringe of submerged or half-submerged reefs of con- 

 siderable area, and stretching out in some cases for several miles from the present 

 coast-line. These no doubt form part of the island, now much depressed from a former 

 elevation. They are extremely dangerous to navigation. All round the coast de- 

 tached rocks are visible, occasionally far out to sea. Some sunken reefs are known 



