The Geology and Physical Geography of Jamaica : Study of a 

 Type of Antillean Development. Based u^oon Sm^veys made 

 for Alexander Agassiz. 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 tlie Geolocry of Jamaica, by H. T. de la Beche. Memoir. Trans- 

 actions Geol. Soc. London, 1829. 



2 Quart. Jour. Geol. Soc. London, Vol. XVI. pp. 324-326, 1860. 

 8 Ibid., Vol. XXL pp. 1-14, 1805. 



* Reports of the Geological Survey of Jamaica, London, 1869. 



