ON THE GEOLOGY OF THE NORTH-EASTERN WEST-INDIA ISLANDS. 47 



Ranina found by me in the eocene beds of S:t Bartholomew. According to Guppy the general 

 affinities of the fossils appear to be nummulitic. The lower part of the newer Parian is 

 evidently of the miocene tirne, there being found in it several fossil species, also occurring 

 in the raiocene beds of Anguilla, Jamaica and S:n Domingo. Below the detrital series and 

 exposed near the coast at Matura a newer formation, probably of pliocene date, was dis- 

 covered by Mr. Guppy, who has given a list of the fossil shells found there*;. A great 

 number of the shells belong to still living species, and are remarkable for their small size. 

 According to Mr. Guppy it is probable that the deposit belongs to about the same tirne 

 as the glacial epoch. 



VII. Suinmary of the geology of the West-Indies. 



From the account given above it is seen that the oldest rocks of the West-Indies 

 do not contain fossils and are, on that account, of an unknown geological age. They 

 occur in Trinidad and are called the Caribbean series. They extend farther to the west 

 in the northern part of South America. It seems very uncertaih whether this series occurs 

 in the other West-India islands. 



The oldest fossiliferous rocks of the West-Indian Archipelago belong to the creta- 

 ceous formation. 



The cretaceous formation is observed in Trinidad, Jamaica and in the Virgin-Islands, 

 and it is not improbable that the conglomerates, and the metamorphic and igneous rocks 

 of the large islands of Puerto Rico, S:n Domingo and Cuba may also be found to belong 

 partly to that formation. 



In Trinidad the cretaceous formation seems to be of an older date than the same 

 formation in Jamaica and the Virgin-Islands. One Trigonia resembling T. Boussignaultii 

 is found in the »older Parian» and this circumstance seems to indicate that the tirne for 

 the deposit of those beds is about the neocomian period. 



The cretaceous beds of Jamaica may be classed as a West-Indian equivalent to the 

 European Hippurite lime or to the »Turonien» and Gosau deposit. 



The fact of the rocks in the West-Indian cretaceous formation being mostly igneous 

 or igneo-sedimentary, evidently proves them to have been heaped up in a tirne of power- 

 ful volcanic activity, and, as the miocene formation in several places covers the highly 

 disturbed and metamorphosed cretaceous rocks, in almost horizontal and undisturbed beds, 

 one may conclude that, before the miocene time, the cretaceous rocks were raised to a 

 inountain-chain, having a common direction from east to west and running parallel with 

 the northern coastline of South America. 



Fossiliferous beds belonging to the eocene formation are found in Jamaica, in Tri- 

 nidad (the S:n Fernando beds), as also in S:t Bartholomew. It may be regarded, too, as 

 very probable that the same formation occurs in S:t Martin, Antigua, Guadeloupe (the »pierre 

 a ravets»), Barbados (Scotland), and possibly also in Cuba, San Domingo and Puerto Rico. 

 The eocene rocks of the West-Indies may be classed as ecpjivalents to the lower or 

 middle eocene formation of Europé (the lower »calcaire grossier» of Paris and »Bracklesham 

 beds» in England). 



*) Geolog. Magazine Vol. II (1865) p. 256. 



