10 P- T. CLEVE, 



BucJcs Island, near the east end of Tortola, is a small islet of stratified, amphibolic, 

 and micaceous dark-gray rock. The strata strike N. W. — S. E. and dip to the S. W. 

 about 45°. 



Beef Island is separated from the eastern end of Tortola by a shallow strait. It 

 has a length of 4 kilometers. The highest point is 201 meters. The rock of the island 

 is diorite. Only in the west end some trap-like rocks occur, and in the south-eastern 

 corner is to be found an interesting variety of diorite, composed of hornblend, anorthite 

 and magnetic (titaniferous) iron-ore. The anorthite-diorite has a dark colour and a beau- 

 tiful spheroidal structure, so that the mountains in some spöts seem to be built of large 

 polygonal boulders, between which there are numerous veins of quartz or granite. The 

 granite is a pegmatite of white oligoklase, red orthoklase, half-transparent quartz and bronze- 

 coloured mica. It contains crystals of epidote, nodules of prehnite, rock-crystals and a 

 little magnetic iron. It can scarcely have been an eruptive rock. The oligoklase-diorite 

 resembles the diorite of Mary's Point in S:t John and of Virgin Gorda. I cannot exactly 

 say if the anorthite-diorite is only a local variety of the diorite, or if it forms a large 

 dike in the diorite. The former seems to me more probable. 



Scrub Island, near Beef Island, is long and narrow, reaching the hight of 137 meters 

 above the sea in the eastern part. The west end of the island contains felsitic rocks of 

 a gray or greenish colour, and in the eastern part are dark, not stratified, trap-like rocks 

 sometimes of porphyritic appearance and sometimes resembling a conglomerate. Between 

 Scrub Island and Beef Island lies a small cay, the Dog, of a dark crystaline rock, perhaps 

 anorthite-diorite. 



Great Camanoe, near Scrub Island, has the length from N to S, of 4^ kilometers. 

 The mountains reach the hight of 162—172 meters above the sea. The southern point, 

 the only part of the island I visited, is formed of a yellowish-gray felsitic rock, which 

 contains some hornblend. The northern part probably consists of bluebeache. 



Little Camanoe seems to be a felsitic rock. 



Guana Island north of Tortola has the hight of 247 meters. I have only landed 

 on the southern coast, where the cliffs are composed of a kind of felsite. The rock is 

 dark and conpact, somewhat variolitic, and shows some traces"of stratification. The strike 

 seems to be E — W and the dip to the south. Judging from the colour of the seacliffs 

 the northern part of the island seems to contain bluebeache. 



7. Virgin Gorda is a long and narrow island, extending from east to west to the 

 lenght of about 16 kilometers. The southern part is full of low hills, but in the middle 

 of the island is a mountain called Virgin Peak, rising to the considerable hight of 418 

 meters. The northern part is a very long and narrow branch of this mountain. One may 

 easily distinguish three kinds of rock in Virgin Gorda, viz: diorite in the south, quartzite 

 or metamorphic sandstone in the middle, and felsite in the northern part. The diorite is 

 a middling coarse granular mixture of white lime oligoklase, black hornblend and some 

 mica. The rock has no stratification, but a beautiful spheroidal structure. The surface of 

 the rock is covered with a great number of loose round boulders, sometimes as large as 

 small houses. They are nothing but the harder diorite balls, which have resisted the 

 denudating action, when the softer diorite-mass between thein has been swept away. The 



