[ '.is:-, ] 



XCIV. Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 

 [Continued from p. 820.] 



May 24th, 1911.— Prof. W. W: Watts, Sc.D., M.Sc, F.R.S., 



President, in the Chair. 



^PHE following communication was read: — 



' On the Geology of Antigua and other AYest Indian Islands, 

 with Reference to the Physical History of the Caribean Region.' 

 By It. J. Lechmere Guppy. 



After noticing the work of former observers on the geology of 

 Antigua, the author gives a brief description of the lormations 

 of that island, showing that it is divided into three principal 

 regions— (1) the Volcanic (or Igneous) Region ; (2) the Central 

 Plain ; and (3) the Calcareous Formation : the hrst-nanied being, 

 according to previous authors, the oldest, as it is pre-Tertiary, 

 and the others following in succession. The Calcareous Formation, 

 hitherto considered the newest, contains fossils, of which the most 

 remarkable is a species of Orbitoides. After a discussion of these 

 formations, and especially of the evidence for the so-called ' Oligo- 

 cene' age of the Calcareous Formation, the conclusion is reached 

 that this formation is the oldest — not the youngest, and is probably 

 Focene or older. The island was raised above sea-level by the 

 development of the great Antillian dislocation, which is described, 

 and divides each of the islands of Guadeloupe and Antigua into two 

 parts, of which the eastern is calcareous and the western volcanic. 

 In Antigua the Central Plain intervenes between the two parts, 

 while in Guadeloupe they are only separated by a narrow channel. 

 In support of this proposition the physical features of Antigua are 

 discussed, and it is shown that the island has not been submerged 

 since the volcanic pieriod. 



The position and age of the Scotland Series of Barbados are then 

 discussed, and that Series is shown to be Focene, the lower beds 

 being possibly Cretaceous and being a remnant of the Atlantis 

 Continent. 



The extension, age, and position of the Orbitoides Bed of Trinidad 

 are next dealt with, and some further remarks are added on the 

 physical history of the Caribean Region. 



