ROCK TERRACES. 313 



above its present level the glacial sea stood. These 

 rock terraces could only have been formed so fully as 

 seen here during a vast period, and the ice-foot of Dr. 

 Kane, to which their formation is probably due, must 

 have remained on the shore during the entire year. Fine 

 examples of similar terraces are described and figured in 

 Kane's " Explorations," vol. ii. p.8i. At various points 

 along the coast the joint action of frost, the waves, and 

 floating ice can even now be seen building up these steps 

 in the slopes of trap and syenitic rocks, by taking advan- 

 tage of the jointure and cleavage planes which cross at 

 nearly right angles. At Strawberry Harbor the syenitic 

 rocks have broken oflf into huge cubical blocks of many 

 tons' weight. The rock abounds in cracks and fissures, 

 into which the ice has entered wedge-like, and burst them 

 asunder, while the fragments have been borne away by 

 shore-ice. Thus for a height of five hundred feet the 

 shore consists of a series of steps ten to thirty feet high, 

 forming broad shelves on which the sea-birds build, and 

 where a little vegetation lodges. Where the shore con- 

 sists of trap-rocks, as at Domino Harbor and Tub Island, 

 the steps are much smaller and more numerous. At 

 Domino there are regular steps in the quartzites, which 

 ■lend a very peculiar feature to the shores of the harbor, 

 as at a little distance the rocky slopes descending by 

 hundreds of steps to the water, appear like a lofty beach 

 of bowlders. At Sloop Harbor these rocky steps are of 

 vast extent, their tops shelving inland, and in profile the 

 rocky promontory presents a strange serrated outline 

 when viewed from the sea. The lofty sugar-loaf syenitic 

 island a few miles south of Hopedale, noticed previously. 



