196 



clayey than in other places, but nowhere was any superficial 

 deposit of clay noticed as forming a compacter and more 

 retentive soil. The surface soil is generally white sand, which 

 is almost everywhere exposed owing to the open vegetation. 

 The soil types may be grouped as more or less consolidated 

 sand, travertine limestone, and white drifting sand. 



Tlie foreshore is of two types, rocky or sand. The whole 

 of the way along the south and west coasts, and along much 

 of the east, too, the v/aves wash over a broad pavement of 

 granitic rock that slopes away at a low angle to the sea, or 

 they beat upon a jumbled mass of boulders caused by its 

 destruction. There is thus no room for the development of 

 a littoral flora along most of these coasts, for the consolidated 

 sands rise from the platform of rock at a steep angle to the 

 plateau summit. Only in a few places does the development of 

 a wider boulder breastwork allow of the accunaulation of a 

 little sand at the cliff foot upon which littoral plants appear. 

 On the south coast of the Western Island the cliffs rise 20 to 

 30 yards back from the beach, the intervening area being a 

 level stretch of sand raised some 6 ft. above the shore line. 

 The terrace thus formed is a curious and distinctive feature 

 of the island, that suggests at first sight a raised beach, but 

 which is capable of other explanation. 



True dunes are developed only at the north-east end of 

 each island, especially the western, near the sand-spit that 

 connects the two islands. The strong south and south-west 

 gales sweeping round the corner of the islands deposit the 

 sand in these comparatively calm areas, building up a small 

 but typical coastal dune of the unstable type. 



The summit of the islands is a gently undulating plateau 

 termed' the ''roof" in this sketch. The southern coast is 

 highest, from whence there is a slight slope downwards towards 

 the north, the highest point on the group (159 ft.) being a 

 rounded knoll lying near the south-west corner. 



The partly consolidated sands of the roof and cliffs of the 

 islands are honeycombed by burrows of mutton birds or sooty 

 petrels and penguins. The effect of their activities is to con- 

 stantly disturb the sand between the larger bushes and open 

 the way for wind erosion. The sand which is blown away is 

 either held by vegetation on the roof forming local white 

 dunes, or is blown to the lee-side of the island and washed 

 away. The terrace referred to above on Western Franklin 

 has possibly been formed by such an accumulation of wind- 

 blown sand. 



Once wind erosion starts at any point the effect is cumu- 

 lative, and a "blow out" may develop, as it would in a recent 

 sand-dune area. Several such areas can be seen in various 



