THE MLTAMORPHIC ROCKS OF ADELIE LAND. STILLWELL. 145 



dyke. At the western end of the exposure there are numerous dykes cutting through 

 the gneiss and have a general trend a little east of north. The dykes repeatedly divide 

 and unite with one another. They are mostly quite massive, and little evidence of 

 schistosity is noticeable. The direction of foliation of the gneiss is a little west of north. 

 In addition to the dykes, veins of quartz and felspar with garnet occur in two sets. A 

 north and south set are faulted and displaced a few inches by an east and west set. No 

 ice striae could be found, but the margin of the island, extending back to a height of 

 20ft. above sea level, consists of well-polished rock. The remainder is rough and jagged 

 as a result of longer exposure to atmospheric weathering ; the lower zone has probably 

 been relatively protected by a water or an ice-foot covering. 



Garnet Point. 



Garnet Point is also approached from the mainland by a steep ice ramp. It is 

 situated on the north-east portion of the promontory, and is about 10 milea distant 

 from Cape Gray, and about five miles north of the Cape Pigeon Rocks. It is approxi- 

 mately the same size as the exposure at Cape Gray. A feature of part of this outcrop is 

 the presence of abundant aggregates of garnet and mica, up to 2in. broad, which impart 

 to the rock, even at a distance, a mottled appearance (Plate XXVI., figs. 1 and 2). 

 The outcrop is divided by a steep transverse gully along which a large black dyke 

 appears. The marginal zone of polished rock is again noticeable, and a waterworn 

 pebble of the basic rock was found on a rocky ledge about 20ft. above sea level. 



Cape Pigeon Rocks. 



The Cape Pigeon Rocks are situated on the east side of the promontory and face 

 Watt Bay. They are considerably larger than the preceding exposures, and form 

 two rugged peninsulas which are separated by a narrow sea water channel, and 

 which terminate seaward in a cliff up to 100ft. in height. A panorama of the northern 

 peninsula is shown on Plate XXVIII. They are connected with each other on the 

 landward side by a sloping causeway of ice. The bulk of the rock consists of a 

 very coarse, grey, garnet felspar gneiss whose foliation trends 20 W. of N. It is 

 traversed in numerous places by basic dykes which cut across the foliation. Two large 

 dykes trending a little W. of N. are over 30ft. wide. One outcrops on the northern 

 peninsula and one on the southern (Plate XXVII., figs. 1 and 4). From one of them 

 a small dyke is seen branching off at right angles. They dip at a high angle to the west. 

 Smaller dykes may be only Sin. wide. A large pegmatite vein was noticed. On the 

 southern portion the rock is excessively contorted, and there are numbers of small dark 

 amphibolite patches which are elongated and drawn out in the direction of the foliation. 



StittuxU Island*. 



Stillwell Island is one of the largest members of the Way Archipelago. It is a 

 steep islet, with poor facilities for landing, and its maximum height is about 120ft. 



This information haa been supplied by Sir Douglu Mmwion from hi* diary. 

 SerioB A, VoL m., Part 1 K 



