682 SUB ANTARCTIC ISLANDS OF NEW ZEALAND. [Geology. 



are sometimes separated by quite low saddles. At the east of this part of the coast 

 an inlet — Monument Harbour — reaches two miles into the land. The entrance to 

 a lagoon at the head of the bay is obstructed by a boulder-bank, across which the 

 waves break in rough weather and at high tide only. On either side of Monument 

 Harbour the land rises abruptly, and off its entrance are two needle-shaped islands 

 and a larger block, Jacquemart Island. Further west the coast-line, for the time 

 directed north, strikes straight across Mount Eboule in a vertical cliff, and further 

 westward Mount Dumas presents a vertical front for nearly its whole height of 1,650 ft. 

 Thence the cliffs become low, and there are several outlying islands ; but in the south- 

 west corner Mount Paris is intersected in the same way as Mount Eboule and Mount 

 Dumas. Thence as the coast-line stretches north and east it is relatively low until 

 a point is reached west of Tucker Cove. In the extreme south-west corner of North- 

 west Bay, where a mass of gabbro rock forms a protecting headland, there is a small 

 sandy beach, protected from the violence of the heavy westerly swell by Dent Island, 

 as well as by the westerly point of the bay. The remainder of the coast-line is ex- 

 tremely high and steep, with several outlying rocks. In the north it stretches some- 

 what to the west, and thus forms Courrejolles Point, a jagged promontory separated 

 from the rest of the island by a low neck. 



From this general account it will be noticed that the cliffs are far higher and 

 the outlying islands more numerous on the west and south than elsewhere, and 

 that the only accumulation of shore drift is at the entrance to Monument Harbour 

 lagoon and in the corner of North-west Bay. As will be seen afterwards, the differ- 

 ence in the hardness of the rocks cannot be held to be sufficient to account for the 

 change in height of the cliffs in different parts of the island. The only adequate 

 explanation is to be found in the prevailing south-westerly swell and current, which 

 have effected the removal of large rock-masses in the south and west of the island, 

 and the coast on these sides now strikes across what was the heart of the island. 



The entire absence of terraces in the harbours and on the exposed headlands 

 offers a strong presumption that the island has not been submitted to a movement 

 of elevation since its present features were acquired. The nearly complete absence 

 of bars of drift suggests that the present elevation has not been long maintained, 

 for with such a strong swell and prevailing current from the south-west the drift 

 from even such a short coast-line would be expected to build up a gravel-bank ex- 

 tending north-eastwards from Courrejolles Point. Of this no sign was seen, nor is 

 there any gravel-bank in the island, except at Monument Harbour, where it is but 

 50 yards long, and composed of material derived from the adjacent slopes of Mount 

 Eboule. If the absence of raised beaches and rock shelves is accepted as proof 

 that there has been no recent elevation, and the absence of bars of sand and boulders 

 is proof that the present level has not been long maintained, it is probable that a 

 movement of depression must be in progress. Of such a movement there appears 

 to be sufficient evidence in the existence of such inlets as North-east Harbour and 

 Perseverance Harbour. That both of these are due to an agent of surface-erosion 

 there is no doubt, and, as will be shown later, the present level of their floors may 

 be due to depression since their formation. The large number of outlying islands 

 also appears to be due to the action of depression, which has left the higher summits 

 only above the sea-level, or possibly to the greater resistance offered by the harder 

 rocks to wave-action. It was impossible to visit the islets, so this point could not 

 be settled. 



