CAPE HILLSBOROUGH. 45 



these two shoal bays were all rough slate, or grey- 

 wacke, or quartz rock, with a dip to the west in the 

 only spot where the stratification was discernible. 



March 17, 18. — Running slowly on along shore 

 to Cape Hillsborough, visiting Li. Cumberland 

 Island on our way. This island exhibited a singular 

 mass of rocks, looking as if made up of angular 

 fragments of compact feldspar cemented together. 

 Cape Hillsborough is a bold headland, 900 feet 

 high, very steep nearly all round. Its base was 

 composed of a singular assemblage of quartzose 

 rocks, unstratified, and containing several imbedded 

 minerals. The upper part is composed of stratified 

 materials, in thick, well marked beds, dipping 

 S.W. at an angle of 15°. On the inner side of the 

 headland, accordingly, these rocks are found at the 

 sea level. In the cliff on the north side of the hill, 

 about 300 feet from the summit, the stratified rock 

 is white, earthy, pulverulent, easily decomposing, 

 but pretty tough when in mass ; much worn into 

 hollows with overhanging blocks and ledges. It 

 contains either angular fragments or worn crystals, 

 of a green translucent mineral, like a dull variety of 

 feldspar, but which may be olivine. Large round 

 blocks of a black rock were also seen embedded in 

 it, but in an inaccessible position. The materials, 

 notwithstanding their regular stratification and dip, 

 look very much as if of volcanic origin. In the 

 country at the back were some singular small conical 

 hills, capped by clusters of small basaltic columns. 



