GEOLOGICAL OBSERVATIONS 



travelled by the JSTorthern Party of our expedition in their 

 journey inland to the South Magnetic Pole, as well as 

 with the new land discovered by our expedition to the 

 west of Cape North. iThis vast plateau extending, it is 

 practically certain, for over 1200 miles from north to 

 south, and over 200 miles from east to west, 7000 ft. high at 

 its northern end, and at least 10,000 ft. at its southern, is 

 formed superficially of neve. Doubtless beneath the 

 neve is glacier ice. The neve is possibly of no very great 

 thickness, for the horizontally bedded or gently inclined 

 plateau rocks of the Beacon sandstone formation rise to 

 heights of 8000 to 10,000 ft. above sea-level along the 

 eastern border of the plateau. 



This structure of the plateau is illustrated on the 

 diagram (p. 306). 



(5) Icebergs have already been described under the 

 heading " Barrier Snow- and Ice-fields." 



(6) Pack ice has also been referred to under the head- 

 ing " Sea Ice." It may be noted that in the Ross Sea 

 the bulk of the pack ice, formed chiefly of fractured 

 masses of sea ice, partly of small snowbergs and icebergs, 

 impelled by the south-easterly winds drifts past Cape 

 Adare to the part of the Antarctic Ocean which lies 

 between Cape North and the Balleny Islands. This region 

 appears to be permanently beset with very old pack ice 

 and icebergs. As most of the blocks of sea ice have 

 been twisted and piled on one another, this pack may 

 be described as " screwed pack." 



(7) Thaw- WATER forming Surface Lakes, and 

 Surface^ Englacial or Subglacial Streams. — Some 

 of the streams formed by thaw- water have already been 

 described under the head of glaciers, in the case of the 

 Drygalski Glacier. In the latitude of this glacier in 75° 

 South, the thaw set in about December 10 and lasted to 

 about the third week in January. 



303 



