81 



the south coast and obscure their outcrops, limiting their study^ 

 for the most part, to small, isolated inliers. 



The only granitic outcrop that I had the opportunity of visit- 

 ing was at Cape Willoughby. The Cape is a bold granite foreland 

 at the eastern extremity of Kangaroo Island. Its high cliffs, 

 broken masses, and deep clefts present a scene of rugged gran- 

 deur, especiall} when the storms of the Southern Ocean try their 

 full force on these weather-beaten rocks. The granite consists of 

 pink-colored orthoclase, opalescent quartz, and pockets of biotite-. 

 The rock splits up along joint planes, and is everywhere under- 

 going disintegration by spheroidal exfoliation, producing enor- 

 mous hemispherical or subglobular masses. Near the extreme 

 point of the Cape a large intrusive mass of tine-grained aplite 

 takes the place of the granite, and exhibits numerous reticulated 

 veins penetrating the granite. The line of junction between the 

 granite and aplitic intrusion is very sharp and well defined, and 

 as the latter has not weathered to such a degree as the granite,, 

 the veins stand up as low ridges above the granitic surface. The 

 granite occupies about three miles of coastline, but I had not the 

 opportunity of visiting the points of junction between the 

 granite and the schistose rocks of the district. 



Granite boulders were noticed at some distance inland from 

 the Cape, but with the granite outcrops so near it would be a 

 doubtful matter to refer such scattered granite stones in their 

 present position to the agency of ice. The exposed granite 

 surface was carefully examined for ice marks, but its weathered 

 condition and comparatively rapid exfoliation precluded the 

 possibility of such markings having survived so great an interval 

 of time, except where specially protected. I was, however, 

 struck with the rounded and roche moutoniiee contour of the 

 granite, as it sloped away from the cliffs, and it is quite possible 

 that the larger features of the surface may still retain the outline 

 given to it by the moving ice. 



The sea beach, on both sides of the headland, exhibits a- 

 wonderful assemblage of large, rounded granite boulders, worn 

 by wave action into spherical or subspherical masses piled on 

 each other, and rendering the beach almost impassable to 

 pedestrians. 



At Hog Bay the bed rock is a fine-grained biotite schist, some- 

 times passing into a more siliceous stone, standing at a high 

 angle of dip which varies from 45° to 80° S.E. The whole of 

 the schistose series gives evidence of the great strain it has- 

 undergone in the process of folding, not only in the numerous 

 instances of local contortion, but also by the great number and 

 extent of the quartz veins which run in every direction, and 

 often develop into bunches. The quartz is often tinged with a. 



