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



Surface - covering . 



Nearly the whole surface of the island is covered with vegetation ; only near 

 the tops of the hills and on the sea-shore is solid rock exposed. The upper portion 

 is covered with peat derived from Danthonia and other plants ; but where contacts 

 of the peaty covering with the solid rock were visible there seemed to be little true 

 soil produced from the decay of the underlying rocks. On the very tops of the hills, 

 where peat is frequently absent, there is a residual clay a few inches in depth, no 

 doubt derived from the basalt, and such occurs in basins on the hill-sides, to which 

 it has slipped or been swept by water-action. The covering of peat seems to exert 

 a protective influence on the rocks, so that beneath it denudation does not proceed 

 at such a rapid rate as it would on surface exposed to general atmospheric weather- 

 ing in a moist climate. The same statement is no doubt true, in a modified form, 

 of the lower parts of the slopes when they are protected by forest and a peaty cover- 

 ing derived from liverworts and other plants of similar character. This protection 

 has important bearing on the rate of weathering, and thus, directly or indirectly, 

 on various biological problems in connection with the group. 



Climate. 

 The climate of the islands is dealt with in detail in a separate report. (See p. 789.) 



GLACIATION OF THE AUCKLAND ISLANDS. 



There is evidence that in recent times the Auckland Islands were subjected to 

 a moderately severe glaciation. The direct positive proof of this rests on the fre- 

 quent occurrence of lateral moraines on the sides of both main and tributary valleys. 

 Within the Carnley Harbour drainage-basin good examples are to be seen on the 

 northern slopes of Adams Island, and perhaps best of all on the southern side of 

 the valley running into Coleridge Bay (fig. 7). Here there is a very distinct lateral 

 moraine belonging to an old glacier of the valley type, behind which is a small lake 

 several acres in extent. Close alongside it are two moraines belonging to a more 

 recent tributary glacier. These latter moraines are very similar to the small ones 

 on Ruapehu, and evidently belong to the last phases of the glaciation. 



On the eastern side of Circular Head Peninsula there are well-defined terraces, 

 several hundred feet above the sea, and running for half a mile in a direction parallel 

 to the axis of the valley. They occupy a position sheltered by a projecting spur 

 at their upper end, and, judging from their appearance as seen from below, they are 

 in all probability old lateral moraines ; but this cannot be stated for certain, as op- 

 portunity did not permit of a closer examination. It is not at all likely that they 

 are old river-terraces. 



On the eastern side of the group, in the larger valleys at the head of Norman's 

 Inlet and Smith's Inlet, just north of it, there are lateral moraines of much larger 

 size. These are well seen on the north side of the Norman's Inlet valley, and again 

 between this inlet and the one to the north, for it is almost certain the Norman's 

 Inlet glacier invaded the basin of its neighbour through a marked depression in 

 the valley-wall and the moraine formed under the sheltering influence of the bluff 

 which ends the dividing ridge. In Norman's Inlet, too, there are several morainic 



