ANTARCTIC ADVENTURE AND RESEARCH 



such ridges just off Cape Geology (see Figure 24). 

 They were from one hundred to three hundred feet 

 long and from three to ten feet above the level of the 

 ice. Each ridge closely resembles a capsized canoe, and 

 they recall the earth folds in the Juras or Appalachians. 

 Between the ridges were their complements, the Pres- 

 sure Pools, where the sea-ice was warped down below 

 water level. The largest ridge was where the pressure 

 was greatest, i.e. where Cape Geology projected far- 

 thest. The ridges were parallel to each other, with 

 their axes about northeast-southwest, or nearly at right 

 angles to the shear cracks described above. This six- 

 feet ice can be buckled into remarkably sharp folds — 

 but usually the apex of the fold cracks under the strain. 

 These ridges changed somewhat in form during the 

 month we were surveying Granite Harbor. Other ex- 

 amples have been noted on a larger scale where the 

 Ross Ice Shelf presses onto Cape Crozier, and just 

 south of Cape Evans where a small glacier enters the 

 Bay Ice near Turk's Head. 



In very sheltered bays, such as the drowned Punch 

 Bowl cirque in Granite Harbor (just southeast of the 

 Fiat Iron in Figure 24), or again on the southeast side 

 of Cape Roberts, I came across peculiar forms of bay 

 ice, which do not seem to be described elsewhere. Here 

 a mass of old ice shaped just like a hoof has been 

 driven up into the bay presumably by pressure from 

 the later sea-ice. In accommodating itself to the smaller 

 width of its new position it has split down the center, 

 hence the name Cloven Hoof. In the Punch Bowl 

 cirque the sheet of ice was about six hundred yards 



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