ON THE GEOLOGY OF THE NORTH-EASTERN WEST-INDIA ISLANDS. 43 



»Barbuda contains a formation resembling the coral-limestone of Barbados. It con- 

 sists of a white calcarious deposit full of shells, all of which are, as far as I have exa- 

 mined, of existing species. The existence of a miocene formation in that island seems, 

 nevertheless, to be indicated by the corals described by Dr. Duncan.» 



As all the fossil shells of Barbuda appear to belong to still existing species and 

 the miocene formation of the 'West-Indies contains comparatively few still living species, 

 it may be found most probable that the formation of Barbuda is of a låter date than 

 the miocene time, unless miocene beds also occur in the island together with more re- 

 cent strata. 



Antigua*). The island is composed of different kinds of rocks belonging to diffe- 

 rent geological ages. The oldest formation of Antigua is visible in the south-western 

 corner where it forms a mountainous land with peaks, of which the highest rises about 

 406 meters above the sea-level. 



This formation is composed of basalt of a globular structure and breccias, green- 

 stone and porphyry. In that part of the island veins, containing heavy spar, are found. 



Above this formation a series of stratified feldspatic clays of green or yellow colour 

 occur. The strata dip generally 15° — 20° to the north. Porphyry, greenstone and amyg- 

 daloid are found in this formation, which forms a band stretching from the Five Island 

 division in Dickinson Bay to English Harbour and Willough Bay. Its highest point is 

 Monkey-Hill. Near Drews Hill impressions of leaves, as also fossil wood and some shells 

 and corals are found. A bed of härd, opake, white lime-stone rests unconformably upon 

 this formation. It contains much chert, a great number of shells belonging to the genus 

 Cerithium or Melania, silicified wood, and corals. The chert-formation occurs, according 

 to DtnsrcAN, in the exact position of a fringing reef. The greatest part of the island is a 

 hilly land, consisting of white and yellow inarls and of more or less compact limestone 

 etc. This formation contains a large number of fossil corals and shells, among which are 

 also some terrestrial, but no fossil wood is found here. According to Duncan the fossil 

 coral-fauna has no connection with the extant Caribbean, but it has a great affinity with 

 the miocene fauna of Europé, as well as with what now exists in the Pacific Ocean. The 

 fossil corals prove that the formation is of miocene date (Duncan), and according to Ho- 

 vey about 70 percent of the fossil shells belong to still living species. 



Nevis**) is a high, conical and entirely volcanic island, south of S:t Kitts. It has 

 hot springs, sulphur deposits, and also still working fumarols. 



Redonda is a small and also volcanic island. (De Jonnés L'Hist. des Ant. Franc, 

 pag. 79). 



*) Litterature cm the geology of Antigua: 



1821 Nugent. Description of Antigua. Transact. of Lond. Geol. Soo. 1 Ser. Vol. V pag. 459. 

 1839 Howey. Geology of Antigua. Sillim. Am. Journ. Vol. XXXV p. 75. 



1863 Duncan P. M. On the fossil corals of the West-Indian Islands. Quart. Journ. Geol. Soc. Vol. 

 XIX pag. 408. 



I have not had an opportunity to read the paper by Nugent. 

 **) Macluue. Journal of the Acad. of Nat. Se. of Philadelphia. Vol. I Part. I p. 145. 



