206 CRUISE OF THE NEPTUNE 



thus described by Capt. M'Clintock: " Near Cape Rennell we 

 passed a very remarkable rounded boulder of gneiss or granite ; 

 it was six yards in circumference, and stood near the beach, and 

 some fifteen or twenty yards above it; one or two masses of 

 rounded gneiss, although very much smaller, had arrested our 

 attention at Port Leopold, as then we knew of no such forma- 

 tion nearer than Cape Warrender, 130 miles to the northeast; 

 subsequently we found it to commence in situ at Cape Granite, 

 nearly 100 miles to the southwest of Port Leopold. The granite 

 of Cape Warrender differs considerably from that of North 

 Somerset, the former being a graphic granite, composed of gray 

 quartz and white feldspar, the quartz predominating, while the 

 latter, a North Somerset granite, is composed of gray quartz, 

 red feldspar and green chloritic mica, the latter in large flakes. 

 Both the granite and gneiss of North Somerset are remarkable 

 for their soapy feel.' 



1 To the east of Cape Bunny, where the Silurian limestone 

 ceases, and south of which the granite commences, is a remark- 

 able valley called Transition valley, from the junction of 

 sandstone and limestone that takes place there. The sandstone 

 is red, and of the same general character as that which rests 

 upon the granitoid rocks of Cape Warrender and at Wolsten- 

 holm sound. Owing to the mode of travelling, by sledge on 

 the ice, round the coast, no information was obtained of the 

 geology of the interior of the country, but it appears highly 

 probable that the granite of North Somerset, as well as that of 

 the other localities mentioned, is overlaid by a group of 

 sandstones and conglomerates, on which the Upper Silurian 

 limestones repose directly. A low sandy beach marks the term- 

 ination of the valley to the northward, and on this beach were 

 found numerous pebbles, washed from the hills of the interior, 

 composed of quartzose sandstone, carnelian and Silurian lime- 

 stone.' 



