Les Saintes Trough

Les Saintes Trough
Name	Les Saintes Trough
Type	Submarine trough
Location	Caribbean Sea
Country	France
Region	Guadeloupe

Les Saintes Trough is a submarine trough located in the Caribbean Sea off the southern coast of Guadeloupe in the Lesser Antilles arc. The trough lies near Îles des Saintes and forms part of the complex plate boundary region where the North American Plate, Caribbean Plate, and nearby microplates interact. The feature is proximal to major island arcs such as Montserrat, Dominica, and Martinique, and is studied in relation to neighboring structures like the Puerto Rico Trench and the Venezuelan Basin.

Geography and setting

The trough occupies a bathymetric depression south of Guadeloupe (French overseas region), running roughly parallel to the Lesser Antilles volcanic arc and adjacent to the Antilles Current, Caribbean Sea circulation, and the continental margins of South America and Central America. Nearby maritime features include the Port-au-Prince Basin, the Grenada Basin, and the Aves Ridge. Political jurisdictions implicated by proximity include France (overseas territories), Dominica (Commonwealth of Dominica), and Montserrat (British Overseas Territory). The trough's bathymetry influences navigation routes used by vessels between Miami, Panama Canal, Curacao, and Trinidad and Tobago.

Geology and formation

The trough formed during Cenozoic convergence associated with subduction of the Atlantic Oceanic crust beneath the Caribbean Plate, and it records processes similar to those documented at the Andean subduction zone and the Aleutian Trench. Regional magmatism producing the Lesser Antilles arc links to volcanic centers such as La Soufrière (Guadeloupe), Soufrière Hills, and Mount Pelée. Sedimentary fill and structural evolution reflect influences from events like the Paleogene–Neogene transition, the uplift episodes related to the Eocene and Oligocene intervals, and basin development comparable to the Gulf of Mexico and Bahamas Platform histories. Tectonic inheritance from the opening of the Central Atlantic and motions described in reconstructions by the USGS contribute to the trough's architecture.

Tectonics and seismicity

The trough is situated within a seismically active segment of the Lesser Antilles subduction system, with earthquake catalogs compiled by institutions such as the USGS National Earthquake Information Center, Sismologie Antilles, and the International Seismological Centre. Notable regional seismic events linked to the plate boundary include ruptures analogous to the 1635 Saint Barthélemy earthquake and modern tremors recorded near Dominica earthquake (2004) and Montserrat volcano eruptions (1995–1998). The tectonic regime includes accretionary prisms, back-arc deformation similar to the Mariana Trough, and transform interactions comparable to the Enriquillo-Plantain Garden fault zone. Geodetic measurements from GPS campaigns, surveys by IPGP, and regional monitoring by NOAA document strain partitioning, slip rates, and seismic hazard assessments affecting Fort-de-France, Basse-Terre, and neighboring urban centers.

Sedimentology and stratigraphy

Sediment accumulation within the trough comprises hemipelagic muds, turbidites, and coarse-grained slides sourced from island arcs and continental inputs like the Orinoco River and Amazon River plumes. Core studies employ methods refined in programs such as the International Ocean Discovery Program and earlier Deep Sea Drilling Project expeditions to resolve sequences spanning the Pleistocene glacioeustatic cycles and the Holocene transgressive systems tract. Stratigraphic markers include tephra layers correlated with eruptions of La Soufrière (Guadeloupe), Soufrière Hills, and Saint Vincent (La Soufrière, 1902), as well as isotopic signals used in paleoceanographic reconstructions similar to work in the North Atlantic Deep Water studies. Gravity-driven mass-wasting, debris flows, and canyon-channel systems export sediment from islands such as Guadeloupe and Dominica into the trough.

Hydrocarbon potential and mineral resources

Exploration interest in the Caribbean basin has involved regional petroleum systems analogous to those in the Trinidad and Tobago and Venezuela margins; however, the trough's proximity to active arc volcanism and immature source rocks complicates assessments. Prospectivity debates reference basin modeling approaches developed by the American Association of Petroleum Geologists and licensing policies influenced by entities like TOTALEnergies and national authorities of France. Mineral resources of interest include manganese nodules, cobalt-rich ferromanganese crusts, and potential seafloor massive sulfide deposits analogous to those found at hydrothermal systems explored by NOAA OER and the International Seabed Authority in other ocean basins. Environmental considerations draw on conservation frameworks such as the Convention on Biological Diversity and regional fisheries managed under CLME+.

Biological and oceanographic environment

The trough hosts deepwater benthic communities, chemosynthetic assemblages, and pelagic fauna influenced by currents including the Antilles Current and mesoscale features like eddies observed by NASA altimetry. Biota links include deep-sea corals, sponges, and crustaceans comparable to species documented around the Lesser Antilles Shelf and Sargasso Sea interactions affecting migratory routes to Bermuda and Puerto Rico. Oceanographic programs by IFREMER, Woods Hole Oceanographic Institution, and Scripps Institution of Oceanography have characterized temperature, salinity, and dissolved oxygen profiles relevant to fisheries for Caribbean spiny lobster and reef connectivity with protected areas such as Guadeloupe National Park. Conservation and scientific collaboration engage stakeholders including European Union research funding and regional organizations like the Caribbean Community.

Category:Geography of Guadeloupe Category:Geology of the Caribbean Category:Submarine troughs