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James V. Trumbull

Publications and source records attributed to James V. Trumbull.

4 recordsLinked to original sources
USGS1980

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.

Puerto Rico↗
USGS1971

Geology of the insular shelf south of St. Thomas and St. John, U.S. Virgin Islands

A reconnaissance study has been made of the geology of the insular shelf south of St. Thomas and St. John, Virgin Islands. High-resolution seismic-reflection profiling reveals that a buried northeast-southwest striking bedrock ridge controls the shallow structure of the eastern portion of the shelf. This ridge is thought to be related to the Virgin Islands pluton farther north. Bedrock in the western shelf portion is more deeply buried and is thought to be a flatter terrain, probably lithologically similar to rocks exposed on St. Thomas. The sediment cover appears to consist principally of carbonate grains in the sand-size range. This sand is covered to various degrees by carbonate nodules at depths below about 34 m, but at shallower depths the nodules are not present. Three large areas of sandy bottom were mapped 1) west of Brewers Bay, 2) near Buck Island, and 3) off south-central St. John. Variations in the amounts of land-derived particles, organic matter, and silt/clay sized material were mapped in these bodies.

Open-File Report↗