ICE OONCA ON DRYCALSKI BARRIER. 



Snow cornice 

 formed by Fiscesu vima -«- 



■i 



.SOjpg^ards 



Traces of foraminifera 

 on Uie ice at the 

 Sides of Che cracks 



This crevasse widened 



tfafeet m about I3 hours 



ttetir/een 6 am of Dec. nV' 



and Sp.m ofthesameddy 



ICE DONGA ON DRYGALSKI BARRIER 



THE DRYGALSKI ICE TONGUE 55 



to 15 feet iu the direction of the Reeves Glacier. We were, consequently, still 

 in the region of pressure of the Drygalski Barrier. Farther to the north-east was 

 a large moraine bank with blocks of granite up to 7 feet in diameter. This was 

 a reddish porphyritic granite, with pink orthoclase crystals up to 2 inches in 

 diameter. It was associated with sphene-diorites, aplites, and fine-grained dolerite. 

 This large moraine must either have been resting on the sea bottom, or was partly 

 embedded in the surface of some old glacier ice. Sedimentary rocks were not 

 noticed in this moraine. Farther to the north-west, after passing over a little more 

 ice that looked like glacier ice, we passed, at the bottom of a gentle undulation, 

 cracks in the ice with open water in the cracks. We tasted this, and found 

 it to be very salt. There 

 can be no doubt that it 

 was sea water. Beyond, 

 to the north-west, glacier 

 ice belonging to the 

 Reeves Glacier rose against 

 us in great rolls from 50 

 to 80 feet in height, and 

 traversed by a perfect 

 labyrinth of crevasses. 



The line of demarca- 

 tion between the Nansen 

 Piedmont and the Dry- 

 galski Piedmont may, therefore, be di-awn provisionally at these cracks in 

 the sea ice. In retreating from the all but impassable ice waves of the Reeves 

 Glacier towards Backstairs Passage (see Plate IX.) we reached another extensive 

 moraine. 



In addition to numerous large boulders of granite, we found here fragments of 

 sandstone and limestone with small pieces of grey clay shale showing faint 

 imjDression of rootlets (?). This was, no doubt, derived from the Beacon Sandstone. 

 Each boulder was surrounded by a thin crust of ice, through which, when sledging, 

 we continually broke, falling into the thaw-water below. Between this moraine 

 and the rocky coast at Backstairs Passage, a distance of about 1 mile, was a stretch 

 of what certainly appeared to be sea ice, with an occasional open pool like that 

 shown in Plate XII. Fig. 3. 



At the back of the pool is a pressure ridge in the glacier ice or old sea ice. 

 This pressure appeared to come from the Drygalski part of the Barrier. Still 

 farther inland were marine muds, forming conical moimds resting on a foundation 

 of ice. The muds were 20 to 30 feet above sea-level, and washed in among the 

 boulders. This ice tasted slightly saline, but not as salt as typical sea ice. 

 Probably it was old glacier ice ; its salinity was due to its having been over-ridden 



Fig. 12 

 This " donga 



is a shear plane or shear zone in the Drygalski Bariiei-, 

 due to differential movement. The central parts of the donga are 

 probably old sea ice 



