It is generally recognized that from a geological and geophysical standpoint the region of the West Indies is one of the most interesting in the world. Many investigators have studied the geologic formations. Oceanographic expeditions have given valuable data regarding the configuration of the bottom of the Atlantic and the Caribbean around the islands. Two great troughs have been found, one the Bartlett Deep in the Caribbean and the other the Nares Deep to the north of Puerto Rico, along both of which there is much seismic activity. Why do these troughs exist?—what maintains them?—are questions that are often asked but never definitely answered.
During recent years it has been possible to determine values of gravity at a number of places on the islands—notably in Cuba, Santo Domingo, Puerto Rico, and some of the Bahama Islands—and also on the peninsula of Florida. In addition there . . .