Marine geologic map of the Puerto Rico insular shelf, Isla Caja de Muertos area

This marine geologic map covers the western half of the Isla Caja de Muertos shelf off the south coast of Puerto Rico. Coverage extends from Playa de Ponce on the west to Punta Petrona, near the town of Santa Isabel, on the east, a distance of 26 km. Within the mapped area the shelf ranges in width from a minimum of 4 km to a maximum of 18 km. Clover (1971, p. 89) named the shelf for the prominent Isla Caja de Muertos, a small upfaulted block of lower and middle Tertiary rocks located near the center of the map area. The Isla Caja de Muertos shelf is not known to be bounded by faults, though Glover suggested faults on the west and south boundaries, and the bathymetry of the insular slope reveals a large east-west fault about 6 to 8 km south of the shelf edge.