The Geology and Physical Geography of Jamaica: Study of a 
Type of Antillean Development. Based upon Surveys made 
for ALEXANDER Acassız By R. T. HILL. 
INTRODUCTION. 
JAMAICA presents a more favorable opportunity for detailed geologic 
investigation than any other tropical area. The authorities have con- 
structed over 4,000 miles of macadamized highways and two lines of 
railroad across the island in different directions. Bridle paths have 
been cut to the highest peaks and other points of interest. These pub- 
lic works have made excellent exposures of the substructure, far better 
than can be seen in most tropical countries. Furthermore, many years 
ago the English government made, for its time, a most thorough recon- 
noissance geologic report, and map of the island, which served as guides 
for the present study, and relieved us of the preliminary drudgery of 
reconnoissance which ordinarily seriously detracts from the consideration 
of the higher geological questions in the tropics. 
The geology of Jamaica has been studied in situ by several writers, 
the principal of which have been De la Beche,! Barrett,? Wall, Brown,* 
and Sawkins,* all of whom except de la Beche were members of the 
Official Geological Survey. 
De la Beche’s conclusions upon the older formations of the island are 
noted elsewhere. His monograph contains many excellent observations 
concerning the Tertiary and later formations, which in a degree are 
more in harmony with the conclusions to be presented by us than the 
subsequent and more extensive reports of the official surveys which sup- 
planted them. 
1 Remarks on the Geology of Jamaica, by H. T. de la Beche. Memoir. Trans 
actions Geol. Soc. London, 1829. 
2 Quart. Jour. Geol. Soc. London, Vol. XVI. pp. 824-826, 1860. 
8 Ibid., Vol. XXI. pp. 1-14, 1865. : 
* Reports of the Geological Survey of Jamaica, London, 1869. 
