THE DELLBRIDGE ISLANDS 225 



were much weathered. From theu- shattered condition it seems probable that they 

 had fallen from the higher slopes of the island, where there may be kenyte in situ, or 

 where they may have been part of a mantle of moraine debris. 



On November 14th the north-western point of the island was visited by a seal- 

 killing party en route for Tent Island in the motor car, and this portion of the 

 island consists entirely of a massive flow of basalt with small porphyritic felspars, 

 which appears to be dipping to the south. 



Tent Island. Tent Island is nearly rectangular in shape, and is nowhere more 

 than 400 feet high. It was visited on November 14th by a motoring party sent out 

 after specimens of young seals. Ferrar describes its geology in the Geological 

 Memoir of the National Antarctic Expedition, 1901-4, as follows : — 



" The lowest rock exposed is a basalt agglomerate, which occupies the lowest 

 100 feet of the north-west cliff". It is covered by sheets of a vesicular glassy kenyte 

 with lenticular porphyritic crystals of felspar, like the rock of Cape Royds. These 

 rocks have a dip of about 20 degrees, are parallel, and are each almost 20 

 feet thick." 



Our cursory examination of the island confirmed this description, and there is 

 very little that can be added to it. The beds dip about south-east, and the slope of 

 the top of the island agrees with this diji in general direction. On the top of the 

 island is a very beautifully weathered kenyte boulder, which Murray photographed. 



The northern side of the island is deeply cut by a gully worn by water and frost, 

 down which, at the time of our visit, a stream of thaw-water was flowing. All the 

 drifts on the island had a very dirty appearance, owing to the concentration of the 

 dust by the past two or three days' thaw. Quite a quantity of the lighter portion 

 of this sediment was being removed by the water and deposited as a small delta in 

 the ice-foot. The work of the thaw was also evidenced by the quantity of jagged 

 pieces of rock which were lying about the ice-foot, and which had evidently been 

 broken off" by the frost action, and loosened by the heat of the sun. 



Both Tent Island and Inaccessible Island are surrounded by a very typical ice- 

 foot of frozen spray. 



Razor-hack and Little Razor-hack. These islands were not visited by members of 

 the expedition, and the only known specimens from them are a few fragments of 

 olivine basalt and trachyte, collected by the National Antarctic Expedition, 1901-4. 



TURK'S HEAD 



On November 15th the motor took a party down to the Turk's Head to 

 secure the skins of some young Weddell seals, and advantage was taken of this 

 trip to make a geological reconnaissance of this nunatak. Here the rock is ex- 

 posed as a bare cliff', in places over 300 feet high. Screes rest against the cliff" 

 at most places, and the weathered material is lying just at the angle of repose. 



